Primary leptomeningeal T-cell lymphoblastic lymphoma: a rare cause of chronic meningitis

Primary leptomeningeal CD30 positive diffuse large B cell lymphoma disguise as meningioma in a young adult: a case report

BACKGROUND

Primary leptomeningeal lymphoma (PLML) without brain parenchymal involvement or systemic disease is very rare, comprising of approximately 7% of all primary central nervous system lymphomas (PCNSL). PLML is a diagnosis of exclusion which should be confirmed on biopsy after ruling out metastasis from systemic lymphomas and dissemination from PCNSL.

CASE DESCRIPTION

A 21-year-old patient presented with the chief complaints of headache, diplopia, decreased vision for five months, and a swelling on the left side of the forehead for four months. On radiology, a large, lobulated, extra-axial mass lesion along the left frontal region with its base towards dura noted. No parenchymal or subependymal CNS lesions were found on CT/MRI. Histopathology was reported as primary leptomeningeal CD30 positive diffuse large B cell lymphoma.

CONCLUSIONS

PLML is a very rare meningeal tumor that requires a very high index of suspicion and is always a diagnosis of exclusion.

Primary Leptomeningeal Lymphoma: Clinicopathologic Features of 2 Rare Phenotypes

Primary leptomeningeal lymphoma is exceedingly rare. We describe 2 rare lymphoma cases with exclusive leptomeningeal disease: 1 ALK-positive (ALK+) anaplastic large cell lymphoma (ALCL) and 1 primary effusion lymphoma (PEL). Case 1: A 19-year-old man presented with symptoms concerning for leptomeningitis. Cerebrospinal fluid (CSF) analysis revealed lymphocytic pleocytosis. Spine MRI demonstrated pial enhancement from T10 through the conus medullaris and cauda equina enhancement/thickening. A biopsy showed leptomeningeal involvement by large lymphoma cells with hallmark cells and brisk mitotic activity. By immunohistochemistry, cells were CD7/CD30-positive with cytoplasmic ALK staining. No systemic disease was identified. The diagnosis of primary leptomeningeal ALK+ ALCL was made. Despite 2 CSF relapses requiring systemic therapy and autologous bone marrow transplant, the patient was in complete clinical remission 9 years after the diagnosis. Case 2: A 60-year-old, human immunodeficiency virus-positive man presented with symptoms suggestive of leptomeningitis. Brain MRIs revealed multifocal, supratentorial, and infratentorial leptomeningeal enhancement. A right frontal biopsy demonstrated leptomeningeal involvement by large lymphoma cells negative for B-cell immunostains, but CD138, MUM-1, and HHV8-positive, with aberrant CD3 expression. EBV-encoded RNA in situ hybridization was positive. In absence of solid lesions/extracranial involvement, the diagnosis of leptomeningeal PEL was rendered. Despite initial complete remission after chemotherapy, the patient died 9 months later.

Primary leptomeningeal lymphoma masquerading as infectious tubercular meningitis

Primary central nervous system lymphoma (PCNSL) is infrequent and often poses diagnostic conundrums due to its protean manifestations. We present the case of a South Asian young man presenting with raised intracranial pressure and a lymphocytic cerebrospinal fluid (CSF) with pronounced hypoglycorrhachia. Progression of the neuro-ophthalmic signs while on early stages of antitubercular treatment led to additional investigations that produced a final diagnosis of primary leptomeningeal lymphoma. Treatment with chemoimmunotherapy (methotrexate, cytarabine, thiotepa and rituximab (MATRix)) achieved full radiological remission followed by successful autologous transplant. This case highlights the difficulties and diagnostic dilemmas when PCNSL presents as a chronic meningeal infiltrative process. While contextually this CSF is most often indicative of central nervous system tuberculosis and justifies empirical treatment initiation alone, it is essential to include differential diagnoses in the investigation work-up, which also carry poor prognosis without timely treatment. High suspicion, multidisciplinary collaboration and appropriate CSF analysis were the key for a correct diagnosis.