Demonstration of cyclin D1 expression by immunohistochemistry in a CD5-positive small B-cell proliferation is extremely helpful in the diagnosis of mantle cell lymphoma in tissue samples, including bone marrow trephine biopsies (BMTB) and in differentiating them from chronic lymphocytic leukaemia (CLL). Following the identification of cyclin D1 expression in one case of CLL on BMTB, 64 additional cases, which included 25 lymph nodes, one tonsillar lesion, one skin lesion and 37 BMTBs were systematically reviewed for presence of cyclin D1 overexpression. Overall, in seven of 65 samples (approximately 10%) of CLL, a minority of the leukaemic cells in the proliferation centres expressed cyclin D1. Cytogenetic analysis had been performed in three of seven cases and there was no evidence of translocation involving CCND1 locus. Our findings suggest that a small subset of CLL overexpresses cyclin D1 in amounts that can be demonstrated by immunohistochemistry. Our observation has impact on the diagnosis of small B-cell lymphomas in BMTB and other tissue samples.

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL), accounts for ∼5% of all cases of Hodgkin lymphoma and is characterized by involvement of the peripheral lymph nodes. NLPHL occurs in young adults and is associated with frequent relapses. In 3% to 7% of cases, NLPHL progresses to a diffuse large B cell lymphoma. Furthermore, a proportion of NLPHL also have areas with features of T cell/histiocyte-rich large B cell lymphoma (THRLBCL), either at presentation or on follow-up. Here, we describe a 32-year-old man who presented to the emergency department with small bowel perforation. The resected small bowel showed fullthickness mural ulceration and involvement by a lymphoma with features of NLPHL that also had areas resembling THRLBCL. The patient had axillary lymphadenopathy, biopsy of which showed NLPHL with focal THRLBCLlike areas. Such a lymphoma presenting as small intestinal lesion/perforation has not been reported in the literature before. We take this opportunity to review the literature on extranodal presentations of NLPHL and discuss the natural history of this disease.

Acute lymphoblastic leukaemia (ALL) presenting as a transient pancytopenia is known to occur in children and less commonly in adults. The period of pancytopenia usually resolves after about 5-38 weeks, to be followed by overt ALL. The pathogenesis is not known and there are no specific cytogenetic abnormalities. Diagnosis is often difficult during the period of bone marrow hypoplasia. Quantitative flow cytometry can help to establish early diagnosis, and can be used on more patients presenting in a similar way.

The diagnosis of myeloma requires the presence of 10% or more clonal plasma cells on bone marrow examination or of a biopsy-proven plasmacytoma along with evidence of end-organ damage that can be attributed to the underlying plasma cell disorder [1]. The above-mentioned case had >90% neoplastic plasma cells in the bone marrow and a significant anaemia as a result of the bone marrow infiltration. Cytological features of myeloma cells can be highly variable. They include tumors with mature and benign appearing plasma cells; small lymphoid-like cells; atypical but differentiated plasmacytic cells; blastic cells with high nucleus: cytoplasmic ratio and fine chromatin; large cells with immunoblastic features and highly pleomorphic forms. The current case showed immunoblastic features and pleomorphism. Differential diagnosis varies as per the cytological features and includes benign/reactive plasma cell infiltrates, small cell lymphomas, large cell lymphomas, metastatic carcinomas, and other metastatic tumors. Documentation of the expression of immunoglobulin either at protein level or at RNA level confirms the B-cell/plasma cell lineage of these tumors. Expression of CD138, CD79a, and CD56 is helpful in the diagnosis of myeloma, though carcinomas can express CD138 and those with neuroendocrine features can express CD56. Expression of cyclin D1 is noted in 40% of cases and is a very helpful feature in the diagnosis and follow-up of myeloma on bone marrow trephine biopsies [2]. Cases with uniform and strong expression of cyclin D1 are associated CCND1 translocation. A man in his seventies presented with anemia, pyrexia, and chest symptoms. His hemoglobin was 7 g/dL and white cell count 7.7 3 10 9 /L, neutrophils 5.08 3 10 9 /L and platelets 87 3 10 9 /L. His globulin was 105 g/L, and further evaluation of serum proteins showed that he had an IgG Kappa paraprotein of 84 g/L. The urine revealed the presence of an IgG Kappa paraprotein of 5.3 g/L and presence of Bence-Jones protein. On the skeletal survey, there were no osteolytic lesions. Bone marrow aspirate revealed sheets of large abnormal cells with large nuclei and prominent nucleoli. The cytoplasm was basophilic with perinuclear halo (a-c; MGG, 31000). Bone marrow trephine biopsy showed hypercellular marrow (d; H&E, 3100), and was entirely replaced by sheets of atypical large cells with large nuclei having relatively fine chromatin and prominent nucleoli, which were often single and centrally located; they had moderate amounts of cytoplasm and the plasmacytic features with eccentric placement of nuclei being subtle (e; H&E, 3600). The neoplastic cells were positive for CD138 (f), CD56 (g) and a proportion of cells expressed cyclin D1 at variable intensities (h). In-situ hybridization for light chains showed kappa light chain restriction [kappa (i) and lambda (j)] (magnifications of e-j X400).