Diffuse Large B Cell Lymphoma with Pseudoacinar Arrangement: A Potential Diagnostic Pitfall

Excerpt

A 62-year male presented with fever, weight loss and shortness of breath of 2 months duration. He had pallor, hepatosplenomegaly; anemia and thrombocytopenia. Bone marrow smears showed clusters of large pleomorphic atypical cells with frequent acinar arrangement and abundant vacuolated cytoplasm (Fig. 1a–d). No lymphoglandular (LG) bodies were seen, raising the suspicion of metastatic carcinoma. Biopsy showed sheets and interstitial excess of atypical cells with interspersed normal hematopoietic elements (Fig. 2a, b). Immunohistochemistry for Pan cytokeratin was negative, ruling out a carcinoma. Strong membranous positivity for CD45 and CD20 (Fig. 2c–e) was seen, while CD3, CD5, CD23, CD10, CD30, and cyclin D1 were negative. Together with diffuse nuclear MUM-1 positivity (≥ 30%) and CD10 negativity (< 30%), a diagnosis of diffuse large B cell lymphoma (DLBCL), non-germinal center B-cell subtype was offered as per Hans-algorithm [1]. Patient succumbed to heart failure. In view of the absence of lymphadenopathy and any mass lesion on examination and imaging, the patient is likely to have primary bone marrow DLBCL.

…