Blastic plasmacytoid dendritic cell neoplasm: Report of two pediatric cases.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare subtype of acute leukemia that typically follows a highly aggressive clinical course in adults, whereas experience in children with this disease is very limited. We report cases of two children in whom bone marrow showed infi ltration by large atypical monocytoid ‘blast-like’ cells which on immunophenotyping expressed CD4, CD56, HLA-DR and CD33 while were negative for CD34 other T-cell, B-cell and myeloid markers. The differential diagnoses considered were AML, T/NKcell leukemia and acute undifferentiated leukemia. Additional markers CD303/ BDCA-2 and CD123 which are recently validated plasmacytoid dendritic cell markers were done which helped us clinch the diagnosis of this rare neoplasm. An accurate diagnosis of BPDCN is essential in order to provide prompt treatment. Due to its rarity and only recent recognition as a distinct clinicopathological entity, no standardized therapeutic approach has been established for BPDCN.

Morphological spectrum of leukemic mantle cell lymphoma.

Background: Leukemic involvement in mantle cell lymphoma (MCL) is common, and can be secondary to nodal or extranodal disease or can be de-novo. There is paucity of literature that describes the morphological spectrum. Aim: This study was aimed at studying the morphological spectrum of leukemic MCL and to correlate the morphology with other features. Materials and Methods: Twenty six such cases diagnosed over a period of four years were studied. Peripheral blood and bone marrow aspiration smears stained with Wrights stain were examined by three hematopathologists. Immunophenotyping was done using multicolor flow cytometry. Fluorescence in situ hybridization (FISH) done in 12 cases showed t(11;14)(q13:q32). Results: Six cases had de-novo leukemic involvement; while 20 cases had secondary involvement. Morphologically, the cells were small (less than twice the size of red blood cell) or large. Small cell morphology in turn showed irregular nuclear border (n=13) or round nuclear contour (n=6). Large cells had blastic morphology (n=5) or had central prominent nucleoli resembling prolymhphocytes (n=2). Twenty cases showed characteristic immunophenotype of CD5+/CD19+/CD20+/FMC7+/CD10-/CD23- and light chain restrictions. Three cases expressed CD23 and two cases were negative for FMC7. Five out of 12 cases, where FISH was done, showed cytogenetic abnormalities in addition to t(11;14)(q13;q32). Conclusion: Morphological spectrum of leukemic MCL ranges from small cells resembling chronic lymphocytic leukemia (CLL) or follicular lymphoma (FL) to large cell mimicking prolymphocytic leukemia (PLL) or acute leukemia. Large cell morphology was associated with more frequent additional cytogenetic abnormality as well as a poorer outcome.

Clinico-pathological profile of Hairy cell leukemia: Critical insights gained at a tertiary care cancer hospital.

Context: Hairy cell leukemia (HCL) is a rare, low grade, B-cell neoplasm with a characteristic morphologic and immunophenotypic profile. It has to be distinguished from chronic lymphoproliferative disorders because of different treatment protocol and clinical course. Aims: To evaluate clinicopathological features including immunophenotypic analysis of cases diagnosed as HCL. Materials and Methods: The present study included 28 cases diagnosed over a period of nine years (2002-2010). Clinical presentation, complete blood count, bone marrow aspirate, and flow cytometric analysis of cases were reviewed. Treatment and follow-up details (ranging from 3-90 months) were noted. Results: This study revealed 28 cases (referrals-7, indoor-21), aged 26-69 years with a median age of 47 years, with a male predominance (M:F=6:1). The presenting complaints were weakness (80%) followed by fever (56%) and abdominal pain. Physical examination revealed splenomegaly in most patients (92%) and hepatomegaly in a minority (28%). The common laboratory features were anemia in 23 cases, pancytopenia in 14 cases, while two patients had leukocytosis and three patients had normal WBC count. Dry tap was observed in 84% of the cases where hairy cells constituted 16-97% of non-erythroid nucleated cells. Tartarte resistant acid phosphate staining was positive in all the eight cases where it was done. CD5 was negative in all the cases, while CD10 was expressed in three cases (13%) and CD23 in five cases (19%). Conclusions: Though pancytopenia is common, occasional patient can present with normal blood counts or leukocytosis. Few unusual findings include presence of lymphadenopathy, absence of palpable splenomegaly, and expression of CD23 and CD10 by the leukemic cells.

Leukemic phase of anaplastic lymphoma kinase positive, anaplastic large cell lymphoma.

Anaplastic large cell lymphoma (ALCL) is a distinct type of CD30+ T/null-cell non-Hodgkin's lymphoma that frequently involves nodal and extranodal sites. The presence of leukemic phase in ALCL is extremely rare and occurs exclusively with ALK1-positive ALCL. We describe two patients with ALK1-positive ALCL who developed a leukemic phase with rapid progression of the disease. Immunophenotypic pattern assessed on peripheral blood by flow cytometry revealed CD45, CD30, and CD25 positivity in both cases but NPM-ALK1 was expressed in only one case. Both patients developed leukemic phase as a terminal event of the disease and we share the immunophenotypic features of both cases.