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Hematopoietic stem cell transplantation (thoracic complications)

There are many thoracic complications that can occur following hematopoietic stem cell transplantation. These can precipitate during various stages following transplantation and can be either infectious or noninfectious. Complications Early pulmonary edema engraftment syndrome diffuse alveo...

Heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a paradoxical thrombotic state resulting from an immune response to heparin. Epidemiology Occurs in 1:5000 patients who have received heparin, most commonly unfractionated heparin. Pathology HIT is induced by IgG antibodies. Clinical presentation T...

Hepatic lymphoma

Hepatic lymphoma is a term given to any form of hepatic involvement with lymphoma. This can be broadly divided into: secondary hepatic involvement with lymphoma: most common by far, many tend to be non-Hodgkin lymphoma (NHL) 1 primary hepatic lymphoma: extremely rare Pathology Risk factors f...

Hepatic myeloid sarcoma

Hepatic myeloid sarcomas, also referred to as hepatic granulocytic sarcoma or hepatic chloromas, are rare neoplasms comprised of myeloid precursor cells happening in the liver. They are a unique presentation of acute myeloid leukemia (AML). Please refer to the main article on myeloid sarcoma/c...

Hepatosplenomegaly

Hepatosplenomegaly is simply the simultaneous presence of a pathologically-enlarged liver (hepatomegaly) and spleen (splenomegaly). Pathology Etiology Infection Many, many infections can produce a mild concurrent enlargement of the liver and spleen. This list is by no means exhaustive! vira...

Hereditary spherocytosis

Hereditary spherocytosis (HS) (also known as Minkowski-Chauffard disease 1) is a group of hemolytic anemias due to a genetic abnormality of the erythrocyte cell membrane resulting in spherocytes. The clinical spectrum is broad, from a subclinical state to severe transfusion-dependent anemia. Ep...

Histiocyte Society classification of histiocytoses

The Histiocyte Society classification of histiocytoses and neoplasms of macrophage-dendritic cell lineages is currently in its 2016 revision of the organization's initial classification system from 1987. Terminology Histiocytes are mononuclear phagocytes that reside in tissues, including macro...

Histiocytic sarcoma

Histiocytic sarcoma is a rare malignant hematopoietic neoplasm that has been reported in association with other hematological malignancies (particularly B and T cell lymphomas). Pathology It comprises of tumor cells derived from the monocyte/macrophage lineage. Location It usually occurs in ...

Hodgkin lymphoma

Hodgkin lymphoma or Hodgkin disease (HD) is a type of lymphoma and accounts for ~1% of all cancers. Hodgkin disease spreads contiguously and predictably along lymphatic pathways and is curable in ~90% of cases, depending on its stage and sub-type. Epidemiology There is a bimodal distribution i...

Hodgkin lymphoma (pulmonary manifestations)

Pulmonary manifestations of Hodgkin lymphoma are relatively rare, present in 5-12% of patients at the time of diagnosis. It is relatively more common with the nodular sclerosing subtype. Pulmonary involvement usually indicates stage IV disease. Radiographic features Bilateral involvement is ...

How you can help build Radiopaedia.org

Contributing to Radiopaedia.org does not need to be a massive commitment. Even a few minutes here and there can make a real difference. This page is a great place to start if you want to get involved. There are many ways to do this: create your own case library and make your existing cases comp...

H-shaped vertebra

H-shaped vertebrae, also known as Lincoln log vertebrae, are a characteristic finding of sharply delimited central endplate depression, classically seen in approximately 10% of patients with sickle cell disease, and results from microvascular endplate infarction (figure 1) 3. It may occasionall...

Hyperimmunoglobulin IgE syndrome

Hyperimmunoglobulin E (hyper IgE) syndrome (HIES), also known as Job syndrome, consists of a heterogeneous group of complex hereditary combined B- and T-cell immune deficiency diseases characterized by recurrent Staphylococcus aureus chest infections, characteristic coarse facial appearance and ...

Hypersplenism

Hypersplenism is a cytopenia resulting from blood pooling in the spleen and is almost always associated with splenomegaly. Pathology Etiology There is an almost overwhelming list, some more common causes are given below 1,3,4: congestive splenomegaly: cirrhosis, Budd-Chiari syndrome, portal...

Hypervitaminosis E

Hypervitaminosis E (or hypertocopherolaemia) is very rare as vitamin E has low toxicity even in large doses. Clinical presentation In published case reports, patients have presented with a bleeding tendency e.g. cerebral hemorrhage 1. These affected individuals have imbibed supraphysiological...

Hypogammaglobulinaemia

Hypogammaglobulinaemia is an immune disorder characterized by a reduction in all types of gammaglobulins. Terminology While hypogammaglobulinaemia means some of loss of gammaglobulins, a total loss is termed agammaglobulinaemia which can occur in as an x linked form - X-linked agammaglobuline...

Hypovitaminosis K

Hypovitaminosis K (also known as vitamin K deficiency) is caused by a lack of vitamin K in the body. Clinical presentation The main symptoms and signs are related to a clotting dyscrasia as vitamin K is vital as a cofactor for the enzymatic activation of several key components of the clotting...

Idiopathic hypereosinophilic syndrome

Idiopathic hypereosinophilic syndrome (IHES) is a leukoproliferative disorder and refers to a situation when there is an unexplained prolonged eosinophilia with associated organ system dysfunction. The condition can affect several organ systems which includes: heart: cardiac involvement in idio...

Idiopathic noncirrhotic portal hypertension

Idiopathic noncirrhotic portal hypertension is the clinical diagnosis of exclusion featuring portal hypertension without hepatic cirrhosis, vascular obstruction, schistosomiasis, or a variety of other chronic liver diseases. Terminology Prior terms for this entity include noncirrhotic portal f...

Immunity

The human body regularly encounters harmful microorganisms, and because of this it has developed a system of defenses to help identify and eliminate infective pathogens in the body, known as the immune system. Humans have two types of immunity: innate immunity and acquired immunity. innate imm...

Infectious mononucleosis

Infectious mononucleosis (also known as glandular fever) is the term for infection with Epstein-Barr virus (EBV). The infection classically occurs in teenagers and young adults, hence its other name kissing disease. It is usually a clinical diagnosis, with confirmation by serum testing, but may ...

Inflammatory myofibroblastic tumor of the spleen

Inflammatory myofibroblastic tumors of the spleen are rare spindle cells tumors of indeterminate clinical behavior. Please refer to the article on inflammatory myofibroblastic tumors for a broad discussion on the subject. Radiographic features Ultrasound They usually present as a well define...

Intravascular lymphoma

Intravascular lymphoma (IVL), also known as intravascular lymphomatosis, corresponds to a rare variant of extranodal diffuse large B cell lymphoma that affects small and medium-sized vessels and has no specific clinical or laboratory findings. CNS and skin manifestations are the most common form...

Iron

Iron (chemical symbol Fe) is one of the trace elements that is essential for normal human health due to its central importance in the structure and function of hemoglobin and the cytochromes. Chemistry Basic chemistry Iron is a transition metal with atomic number 26 and an atomic weight of 55...

Labeled imaging anatomy cases

This article lists a series of labeled imaging anatomy cases by system and modality. Brain CT head: non-contrast axial CT head: non-contrast coronal CT head: non-contrast sagittal CT head: angiogram axial CT head: angiogram coronal CT head: angiogram sagittal CT head: venogram axial CT ...

Lactate dehydrogenase

Lactate dehydrogenase (LDH or LD) is a key enzyme in most cells, catalyzing the reversible conversion of pyruvate to L-lactate. Its contemporaneous main clinical uses are limited primarily to the investigation of hemolysis, serous collections and as a tumor marker. Physiology L-lactate dehydro...

Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a rare multisystem disease with a wide and heterogeneous clinical spectrum and variable extent of involvement. Terminology Langerhans cell histiocytosis was previously known as histiocytosis X. The newer term is preferred as it is more descriptive of its...

Large bowel lymphoma

Large bowel (colorectal) lymphoma is a very rare tumor, accounting for <0.5% of primary colorectal malignancies, ~1.5% of all lymphomas, and ~15% of gastrointestinal lymphoma. Large bowel lymphoma differs from gastric and small bowel lymphoma in clinical presentation, management, and prognosis. ...

Lead poisoning

Lead poisoning or plumbism is a multisystem condition due to the way in which lead interferes with the function of virtually every organ system. Plumbism most severely manifests due to its devastating effects on the CNS, but it also has important deleterious consequences on the skeletal, renal, ...

Leishmaniasis

Leishmaniasis refers to zoonoses caused by parasites of the genus Leishmania. There are three main forms of leishmaniasis: visceral (also known as kala-azar or dum-dum fever) cutaneous mucocutaneous leishmaniasis Epidemiology Leishmaniasis is a truly global disease with a higher burden in t...

Leukemia

Leukemia is a hematological neoplasm characterized by the overproduction of immature (blasts) or abnormally differentiated cells of the hematopoietic system in the bone marrow that often, but not always, extends into the peripheral blood. This article aims to provide an overview of leukemia as...

Leukemia (CNS manifestations)

Leukemia CNS manifestations can be divided into those related to the disease itself and those associated with its treatment. Leukaemias are hematologic malignancies in which occur a proliferation of hematopoietic cells at an undifferentiated or partially differentiated stage of maturation. CNS ...

Leukemia (musculoskeletal involvement)

Musculoskeletal involvement of leukemia is not always apparent on imaging, although the disease is per se characterized by the bone marrow infiltration. Leukemia is a hematological neoplasm characterized by the overproduction of immature (blasts) or abnormally differentiated cells of the hemato...

Leukemia (testicular manifestations)

Leukemia testicular manifestations, or testicular leukemia, can be seen in patients during and after acute leukemia. The blood-testis barrier limits chemotherapy from reaching the testicle, and therefore the testicle can act as a harbor for leukemic cells. typically presents with painless testi...

Leukemic cell lysis pneumopathy

Leukemic cell lysis pneumopathy, also referred to as acute lysis pneumopathy, refers to an acute respiratory failure that can occur in patients with leukemia after the initiation of chemotherapy, particularly in those with hyperleukocytosis. On imaging, it manifests with features of acute respir...

Leukemic infiltration of liver

Leukemic infiltration of the liver can occur with several forms of leukemia inclusive of acute myeloid leukemia (AML), acute lymphoid leukemia (ALL) and chronic myeloid leukemia (CML). Radiographic features CT Described features are non-specific but include: hepatomegaly periportal low att...

Leukostasis

Leukostasis, also known as symptomatic hyperleukocytosis, is a medical emergency in patients with leukemia, particularly acute myeloid leukemia (AML) and in the blast phase of chronic myeloid leukemia (CML), characterized by the over-accumulation of leukemic cells within the small vessels. Altho...

Li-Fraumeni syndrome

Li-Fraumeni syndrome is a hereditary cancer syndrome due to mutations in the tumor suppressor gene TP53. Approximately half of affected individuals are thought to develop invasive cancer by 30 years of age 1. Associated malignancies sarcomas osteosarcoma rhabdomyosarcoma CNS tumors gliomas...

Low attenuation lymphadenopathy

Low attenuation lymphadenopathy refers to abnormal lymph nodes that on CT appear to have lower attenuation than other soft tissues. This category can be split into two types: cystic (necrotic) lymph nodes metastatic carcinoma (or lymphoma) infections (tuberculous or fungal) cavitating mesent...

Lugano classification (lesion measurement guidelines)

The Lugano classification is a lymphoma staging system resulting from recommended changes in 2011 to the Cotswolds modified Ann Arbor staging. This article outlines the lesion measurement guidelines for the system: Eligible lesions lymph nodes: the longest diameter in axial plane should be >1....

Lugano classification (PET-CT treatment response)

The Lugano classification is a lymphoma staging system for non-Hodgkin and Hodgkin lymphoma. This article outlines the classification's response to treatment based on PET-CT. Also included in the classification are staging and response to treatment based on CT. Scoring system The Lugano clas...

Lugano classification (response to treatment on CT)

The Lugano classification is a lymphoma staging system resulting from recommended changes in 2011 to the Ann Arbor staging with Cotswolds modifications. This article outlines the classification's response to treatment based on CT. Also included in the classification are staging and reponse to ...

Lugano staging classification

The Lugano staging classification is the lymphoma staging system that is most commonly used in clinical practice currently. The categories for initial staging are defined in this article. See separate articles for the Lugano criteria for response assessment by PET-CT or by CT alone, as well as g...

Lupus anticoagulant

Lupus anticoagulant refers to an immunoglobulin that binds to phospholipids and proteins associated with cell membranes. The name lupus "anticoagulant" is in fact a misnomer where it is a prothrombotic agent. Patient's with lupus anticoagulant have a primary hypercoagulable state and are greater...

Lymphatic system

The lymphatic system (also known as the lymphoid system or systema lymphoideum in Terminologia Anatomica) is the collective term given to the lymphatic vessels and lymphoid tissues in the body 1,4. Terminology Occasionally the lymphatic system is considered with the reticuloendothelial system ...

Lymph node enlargement

Lymph node enlargement (rarely lymphadenomegaly) is often used synonymously with lymphadenopathy, which is not strictly correct. Terminology Lymphadenopathy (or adenopathy) is, if anything, a broader term, referring to any pathology of lymph nodes, not necessarily resulting in increased size; ...

Lymph node imaging

Lymph node imaging is a useful technique, aiding the clinician in determining whether nodes are benign or malignant. Multiple modalities are used for the assessment and characterization of lymph nodes, each with its advantages and drawbacks. Modalities Ultrasound size number shape contour...

Lymph nodes

The lymph nodes (commonly shortened to nodes, and known as nodus lymphoideus in TA 4) collectively form one of the secondary lymphoid organs. Macroscopically, a normal lymph node is a small ellipsoid structure, approximately 0.1 to 2.5 cm in maximal length 2,3. Nodes often possess a reniform mo...

Lymphoid organ

The lymphoid organs represent sites in the body in which lymphocytes are concentrated. They are divided into primary and secondary lymphoid organs 1. Primary Primary lymphoid organs are responsible for the generation of new lymphocytes: bone marrow thymus Secondary Secondary (a.k.a. periph...

Lymphoma

Lymphoma (historically lymphosarcoma was used for diffuse forms of the disease) is a malignancy arising from lymphocytes or lymphoblasts. Lymphoma can be restricted to the lymphatic system or can arise as extranodal disease. This, along with variable aggressiveness results in a diverse imaging a...

Lymphoma of the spinal cord

Lymphoma of the spinal cord is an uncommon manifestation of lymphoma. Although lymphoma more commonly involves the vertebral body (vertebral body tumors) or epidural compartment, intramedullary lymphoma may rarely occur. Apparent intramedullary spinal cord lymphoma may often, in fact, represe...

Lymphoma of the uterine cervix

Lymphoma of the uterine cervix is generally uncommon and when it does occur tends to present as cervical involvement with added background multi-organ disease rather than isolated primary cervical lymphoma 1. It is often considered part of the spectrum of uterine lymphoma. Epidemiology In the ...

Lymphoma response to immunomodulatory therapy criteria (LYRIC)

The Lymphoma Response to Immunomodulatory Therapy Criteria (LYRIC) represents an adaptation of the Lugano classification for the evaluation of lymphoma after immune-based treatment. During immunomodulatory agents (e.g. checkpoint inhibitors) therapy, imaging findings suggestive of progressive d...

Lymphoma (staging)

Many lymphoma staging systems for both Hodgkin lymphoma and non-Hodgkin lymphoma have been developed. The most widely used currently is the Lugano staging classification, which also separately defines criteria for response to treatment assessed by PET-CT or by CT alone. Patients having undergon...

Lymphomatoid granulomatosis

Lymphomatoid granulomatosis, also known as angiocentric lymphoma or angiocentric immunoproliferative lesion, is a rare type of non-Hodgkin's lymphoma associated with Epstein-Barr virus infection. Pathology There is a recognized association with antecedent infection with the Epstein Barr virus...

Lymphomatoid granulomatosis (CNS manifestations)

Lymphomatoid granulomatosis of the central nervous system is uncommon, but represents the second most common site of involvement in patients with systemic lymphomatoid granulomatosis, after the lungs, which are most commonly involved. It is considered one of the immunodeficiency-associated CNS l...

Lymphomatoid granulomatosis (pulmonary manifestations)

Pulmonary manifestations of lymphomatoid granulomatosis are important since the lung is one of the most frequent sites of involvement in lymphomatoid granulomatosis. It falls under the group of pulmonary angiitis and granulomatosis. Pathology Some consider the condition to be midway between ov...

Lymphopenia

Lymphopenia (also known as lymphocytopenia, hypolymphemia and sublymphemia) is a deficiency of circulating lymphocytes 1. It may be either primary or secondary. Terminology The spelling lymphopaenia is erroneous and should never be used. Pathology Etiology Primary primary immunodeficienci...

Magnetic resonance lymphangiography

Magnetic resonance lymphangiography (MRL) is an imaging technique used to visualize and map the lymphatic vessels. The technique is used for treatment planning in supermicrosurgical procedures, including lymphaticovenous anastomosis, lymphaticolymphatic bypass and vascularized lymph node transfe...

MALT lymphoma

Mucosa-associated lymphoid tissue (MALT) lymphoma, also called extranodal marginal zone B-cell lymphoma, is a type of low-grade extranodal lymphoma. Epidemiology MALT lymphoma represents ~7.5% of non-Hodgkin lymphomas. The average age of presentation is 60 years with a slight female predomina...

Mannose-binding lectin deficiency

Mannose-binding lectin deficiency is a condition that affects the immune system. Epidemiology It may be prevalent in 10-30% of the general population. Associations disease progression in cystic fibrosis 1 severe disease in those with bronchiectasis without underlying cystic fibrosis more s...

Mantle cell lymphoma

Mantle cell lymphoma (MCL) is a type of non-Hodgkin lymphoma (NHL) and accounts for ~5% of all NHL. It is a malignant neoplasm of virgin B cells that closely resemble normal mantle zone B cells surrounding germinal centers. Epidemiology They occur in older adults (mean age ~60 years), and ther...

Marginal zone lymphoma

Marginal zone lymphomas are a group of low grade Non Hodgkin's lymphoma (NHL) that arise from the marginal zone of B cell germinal follicles in lymph nodes. There are three types of marginal zone lymphomas depending on the site of origin. These include: Mucosa-accosiated lymphoid tissue (MALT) s...

Mediastinal lymph node enlargement

Mediastinal lymph node enlargement can occur from a wide range of pathologies, either by its own or in association with other lung pathology. Historically, a size cut-off of 10 mm short-axis diameter was used. Terminology Although mediastinal lymphadenopathy is used interchangeably - by some ...

Mesenteric lymph nodes

In the premultidetector CT era, mesenteric lymph nodes (often shortened to mesenteric nodes) were only really appreciated when enlarged. Following the advent of routine volume acquisition CT (and especially coronal reformats) lymph nodes in the mesentery are commonly seen in normal individuals, ...

Monoclonal gammopathy of undetermined significance

Monoclonal gammopathy of undetermined significance (MGUS) is the most common plasma cell disorder and refers to the presence of an abnormal monoclonal antibody in the blood but the absence of the overt bone marrow and clinical signs of multiple myeloma. Epidemiology MGUS is the most common pla...

MR liver iron quantification

MR liver iron quantification is a non-invasive means of measuring liver iron concentration, a key indicator in the management of patients with hemochromatosis (primary or secondary). Advantages Apart from being non-invasive, sampling occurs in a large cross-section of the liver, as opposed to ...

Multiple myeloma

Multiple myeloma is a monoclonal gammopathy and is the most common primary malignant bone neoplasm in adults. It arises from red marrow due to the monoclonal proliferation of plasma cells and manifests in a wide range of radiographic abnormalities. Multiple myeloma remains incurable. Terminolog...

Multiple myeloma (extraosseous manifestations)

Extraosseous myeloma refers to any manifestation of multiple myeloma where there is plasma cell proliferation outside the skeletal system. This can potentially affect any organ system and the reported disease spectrum includes: reticuloendothelial system lymph nodes (considered to be most comm...

Muscle lymphoma

Muscle lymphoma is a rare manifestation of lymphoma. Epidemiology Muscle lymphoma is rare, representing <2% of all lymphomas. The average age of presentation is 70 years 1. Clinical presentation Focal swelling and/or pain along with B-type symptoms 2. Any muscle can be involved but most comm...

Myelodysplastic syndrome

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal hematological stem cell disorders characterized by dysplasia and ineffective hematopoiesis. It carries a risk of transformation to acute leukemia. Epidemiology Its overall incidence is thought to be around 3.3 per 100,000. The...

Myeloproliferative neoplasm

Myeloproliferative neoplasms are a diverse group of conditions that are characterized by an excess of terminally differentiated myeloid cells (red cells, white cells, and/or platelets) in the peripheral blood. Pathology Classification The classic four types of myeloproliferative neoplasms are...

Necrobiotic xanthogranuloma

Necrobiotic xanthogranulomas are a rare form of cutaneous non-Langerhans cell histiocytosis. Epidemiology The condition occurs mostly in older adults 2. Clinical presentation Patients demonstrate cutaneous papules that develop into large, firm plaques, papules and nodules, which are often ye...

Neuroacanthocytosis syndromes

Neuroacanthocytosis syndromes (NAS), previously known collectively as Levine-Critchley syndrome, are characterized by basal ganglia degeneration, acanthocytosis, and normal serum lipoprotein. There are four core NAS: chorea-acanthocytosis (ChAc) McLeod syndrome (MLS) Huntington disease-like ...

Neurolymphomatosis

Neurolymphomatosis is a rare condition characterized by the direct invasion of the cranial and peripheral nerves and roots by lymphoma, in the great majority B-cell non-Hodgkin lymphoma. It should be differentiated from non-tumor conditions associated with lymphoma that also affect the peripher...

Nodular lymphoid hyperplasia

Nodular lymphoid hyperplasia (NLH) is a type of rare, benign, lymphoproliferative disease. It is most commonly reported affecting the gastrointestinal and respiratory systems. The presence of gut/mucosa associated lymphoid tissue (GALT/MALT) can be seen in children and young adults as a normal ...

Non-Hodgkin lymphoma

Non-Hodgkin lymphoma (NHL) is a catch-all term for lymphomas that are not of the Hodgkin subtype. It is a heterogeneous group of malignancies in terms of histology, clinical presentation, and prognosis. See 2008 WHO classification for further information on subtypes.

Non-lymphomatous pulmonary lymphoid disorders

There are several non-lymphomatous lymphoid disorders that can affect the lung. This implies that they consist of lymphoid tissue but may not have progressed as far as an overt lymphoma. They include: Castleman disease plasma-cell granuloma lymphocytic interstitial pneumonia angioimmunoblast...

Normal gastrointestinal tract imaging examples

This article lists examples of normal imaging of the gastrointestinal tract and surrounding structures, divided by modality. Plain radiograph abdominal film example 1 example 2: erect and supine example 3: pediatric example 4: pediatric example 5: young adult male Barium studies barium ...

Normal hepatobiliary imaging examples

This article lists examples of normal imaging of the liver and biliary tree and surrounding structures, divided by region and modality. Liver Plain radiographs liver silhouette: example Ultrasound liver ultrasound example 1 with shear wave elastography liver Doppler ultrasound: example ne...

Ommaya reservoir

Ommaya reservoir, also known as Ommaya shunt, is a device consisting of an intraventricular catheter connected to a reservoir (port) implanted beneath the scalp. It is used for intrathecal administration of medication such as chemotherapy (mainly in the treatment of meningeal lymphomas, but also...

Pancreatic lymphoma

Pancreatic lymphoma is most commonly a B-cell sub-type of non-Hodgkin lymphoma. Epidemiology Pancreatic lymphoma is typically seen in middle-aged patients with a mean age of around 55 years old and is more common in immunocompromised patients. Clinical presentation Symptoms are often non-spe...

Paraneoplastic syndromes

Paraneoplastic syndromes occur secondary to the indirect effects of a malignancy and occur remotely to the primary malignancy. Symptoms are mediated by cytokines, hormones or immune cross-reactivity. These syndromes can cause a diverse range of symptoms and can affect multiple systems. Epidemio...

Paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hematopoietic stem cell disorder whereby some of the red blood cells produced are defective and are susceptible to premature destruction by the immune system, leading to hemoglobinuria. Terminology The term comes from a mistaken 19th cen...

Periprocedural anticoagulation

When planning an interventional procedure a patient’s coagulation status must be assessed and optimized to best balance the risk of bleeding and thrombosis. The following must be considered; bleeding risks associated with the procedure medications the patient is taking that alter coagulation o...

Perisplenitis

Perisplenitis is acute inflammation of the splenic capsule and its peritoneal covering. Epidemiology It is seen uncommonly but there is no data on its actual incidence. Clinical Presentation It is seen usually in young and middle-aged patients, with acute left hypochondrial or lower chest pa...

Pernicious anemia

Pernicious anemia (PA) is the commonest cause of vitamin B12 deficiency (or hypocobalaminemia) in the world, due to an autoantibody against intrinsic factor, the cofactor required for absorption of this vitamin. Epidemiology Pernicious anemia is the commonest cause of hypovitaminosis B12 globa...

PET-CT indications

PET-CT is a combination of cross-sectional anatomic information provided by CT and the metabolic information provided by positron emission tomography (PET). PET is most commonly performed with 2-[F-18]fluoro-2-deoxy-D-glucose (FDG). Fluorine-18 (F-18) is an unstable radioisotope and has a half-...

Pituitary lymphoma

Pituitary lymphoma is very rare, although lymphomatous (or leukemic) infiltration of the perisellar dura is not infrequently encountered as part of more widespread CNS disease. This article concerns itself with involvement of the pituitary itself rather than the region more broadly. For a genera...

Plasma cell leukemia

Plasma cell leukemia (PCL) is a rare and aggressive form of leukemia and plasma cell dyscrasia. It can be divided into primary (pPCL) and secondary (sPCL) following previously diagnosed multiple myeloma. It is also considered clinically and genetically distinct from multiple myeloma. Plasma cel...

Plasmacytoma

Plasmacytomas are discrete, solitary tumors of neoplastic monoclonal plasma cells in either bone or soft tissue (extramedullary). It is a rare tumor that is associated with latent systemic disease in the majority of affected patients. In contradistinction to multiple myeloma, there is minimal or...

Pleural lymphoma

Pleural involvement with lymphoma can occur in two situations: primary pleural lymphoma primary effusion lymphoma secondary involvement of the pleura with lymphoma

POEMS syndrome

POEMS syndrome is the acronymic name for a rare multisystem paraneoplastic disorder comprising of a minimum of three of the following features in the setting of a plasma cell dyscrasia: P: polyneuropathy O: organomegaly hepatomegaly, splenomegaly or lymphadenopathy E: endocrinopathy diabete...

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