Rhinoscleroma

Rhinoscleroma is a chronic granulomatous infection involving the upper respiratory tract due to Klebsiella rhinoscleromatis. It initially involves the nasal mucosa but it may progress to involve any other part of the upper respiratory tract.

Untreated rhinoscleroma slowly progresses over many years ¹.

Clinical presentation

Patients most often present with nasal obstruction. Other nonspecific symptoms are often encountered such as epistaxis, rhinorrhearhinorrhoea, dysphagia, stridor, and dysphonia.

Epidemiology

Patients with rhinoscleroma are usually between 10 to 30 years old. Poor hygiene, prolonged close contact, and malnutrition are considered risk factors. It It is endemic in Central America, Egypt, tropical Africa, India, and Indonesia ³.

Radiographic features

Characteristic radiological feature of rhinoscleroma is the presence of nasal mass with the following criteria; ^{4, 5,5}:

CT

• bilateral or unilateral expansile nasal masses, lesions are usually homogeneous, hyperdense and non-enhancing
• masses usually extend through the nasal narenares anteriorly and into the adjacent paranasal sinuses
• lesions line the sinus wall causing bone sclerosis, bone thinning (pressure atrophy) or it may absorb it with extra-sinusextrasinus extension
• no bone destruction which helps to differentiate it from malignant lesions
• in longstandinglong standing cases, rhinoscleroma may extend to involve other parts of the upper respiratory tract, :
  • such as phayrnxpharynx with nodular infiltration of the orophayrnxoropharynx, tonsillar bed, soft and hard palate. It
  • may also show laryngotracheal involvement, the usual site of laryngeal involvement is the glottic–subglottic region showing concentric narrowing of the airway, thickening of the tracheal wall and nodular thickening of the tracheal mucosa ⁵

MRI

lesionsLesions demonstrate characteristic signal intensity ^4,5:

• T1: mild to marked high signal intensity secondary to increased protein content within Mikulicz cells and RusselRussell bodies
• T2:  hyperintense hyperintense due to its high cellular component with hypointense foci of fibrosis
• T1 C+ (Gd): inhomogeneous contrast enhancement secondary to areas of fibrosis.
• DWI: diffusion restriction with low apparent diffusion coefficients values secondary to high cellularity, which could mimic malignancy

Differential diagnosis

The differential diagnosis of nasal masses includes granulomatous and neoplastic diseases which canmay mimic rhinoscleroma ⁵.

Granulomatous diseases include:

• infectious granulomatous processes:
  • bacterial (tuberculosis, actinomycosis, leprosy, and syphilis),
  • fungal (histoplasmosis, sporotrichosis, paracoccidioidomycosis)
  • parasitic (mucocutaneous leishmaniasis)
• noninfectiousnon-infectious granulomatous diseases (granulomatosis with polyangiitis and sarcoidosis)

Neoplasms:: such as(lymphoma and sinonasal carcinoma). Expansion

Findings helping differentiate rhinoscleroma from nasal malignancy:

• expansion of the nasal cavities,
• scalloping of the sinus wall,
• lack of bone destruction and
• hyperintensity on T₁ help to differentiate rhinoscleroma from nasal malignanciesT1

Differential diagnosis for tracheal subglottic narrowing includenarrowing includes:

• diffuse tracheal narrowing narrowing
• focal thickening of the tracheal wall