Primary mediastinal large B-cell lymphoma

Case contributed by Dr Henry Knipe

Presentation

Vomiting, tachycardic ?free gas/perforation.

Patient Data

Age: 20
Gender: Female
X-ray

Chest

The cardiomediastinal contour is markedly abnormal. There is abnormal nodular expansion of the left side of the superior mediastinum, involving the soft tissues adjacent to the aortic knuckle which is indistinct; the aortopulmonary window which is expanded and the left side of the heart. The trachea is displaced to the right that does not appear significantly narrowed in this projection. The cause for this is unclear however differential diagnosis includes an abnormal mediastinal soft tissue mass or lymphadenopathy. Further evaluation with a CT scan through the chest is required.

The heart size is difficult to assess. There is mild apparent elevation of the left hemidiaphragm. The underlying lungs and pleural spaces are clear. No evidence of free subphrenic gas.

Mediastinum: A large soft tissue mass in the left anterior mediastinal measures up to 8.3 x 6.5cm in the axial plane and extends into the left hemithorax.. In the craniocaudal axis, the mass extends from the medial aspect of the left hemidiaphragm cranially beyond the thoracic inlet to the level of the thyroid gland. In the superior mediastinum, the mass encases both brachiocephalic and left subclavian and left common carotid artery and the proximal large veins and results in rightward displacement of oesophagus and trachea. The mass encases the left main bronchus and lies just anterior to the left bronchus intermedius. No hilar, axillary or subclavian lymphadenopathy. There is probable involvement of both left recurrent laryngeal and phrenic nerves.

Chest: Minor groundglass change in the perihilar region of the left lower lobe. The lungs and pleural spaces are otherwise clear. In particular, there are no pulmonary parenchymal nodules or nodes identified.

Case Discussion

Completion CT staging of the abdomen and pelvis was unremarkable. The patient underwent an US-guided biopsy of the superior mediastinum mass. 

Histopathology report

MACROSCOPIC DESCRIPTION: 1. "Chest biopsy": One cream core biopsy up to 9mm. A1. 2. "Chest Bx": One cream core biopsy up to 8mm. A1. (SEK)

MICROSCOPIC DESCRIPTION: 1&2. Sections show cores of tissue containing a dense mixed cellular infiltrate comprising large atypical cells with admixed small regular appearing mononuclear cells. The large aberrant cells have elongate sometimes folded nuclei with prominent nucleoli, occasional bilobed nuclei and indistinct cytoplasm. In areas the large cells are the predominant cell type and form sheets. There are many apoptotic cells. There is necrosis at the end of one of the biopsies. There is patchy, fine fibrous stroma without obvious compartmentalization. The admixed mononuclear cells mostly appear to be lymphocytes. There are occasional neutrophils. One eosinophil is noted. By immunohistochemistry the large cells are CD45+, CD20+, CD79a+, PAX5+, CD30+(focal and weak), CD15-, CD3-, ALK1-, EBV-LMP-, EBV-CISH-, CD23+, bcl6+, CD5-, EMA-. Fascin is difficult to interpret.

DIAGNOSIS: 1&2. Mediastinal mass biopsies: Large B-cell lymphoma with features favouring Primary mediastinal large B-cell lymphoma.

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Case information

rID: 26688
Case created: 3rd Jan 2014
Last edited: 5th Sep 2015
Systems: Haematology, Chest
Inclusion in quiz mode: Included

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