Fine-Needle Cytological Characteristics of Carcinoma Breast with Medullary or Medullary-like Features Masquerading as Dendritic Reticulum Cell Sarcoma: An Attempt to Explore the Reasons for Erroneous Cytologic Interpretation.

BACKGROUND: Infiltration of tumors by dendritic reticulum cells (DRC) reflects the host immune defense mechanism. We observed three breast carcinomas cases with dense tumor-infiltrating DRC and lymphocytes in fine-needle aspiration (FNA) smears, leading to cytodiagnosis or differential diagnosis of dendritic reticulum cell sarcoma (DRCS). An attempt was made to find out the reason behind such an erroneous interpretation. MATERIALS AND METHODS: Between 2009 and 2014, two cases were diagnosed as DRCS of the female breast by FNA cytology and in one case possibility of DRCS was considered along with medullary breast carcinoma (MBC). We compare and contrast the cytomorphological features of these three cases with those of nine cytologically diagnosed MBC. RESULTS: Cases diagnosed as DRCS or MBC showed singly dispersed tumor cells, nuclear pleomorphism, bare nuclei, prominent nucleoli, and presence of lymphocytes. There was no significant difference between the two groups for discohesive clusters, syncytial clusters, plasma cells, neutrophils, foamy histiocytes, and necrosis. However, there was significant difference for presence of cohesive clusters (0% DRCS and 100% MBC, P = 0.00485), severe degree (+++) of pleomorphism (100% DRCS vs. 11.1% MBC, P = 0.01818), +++ DRC (P = 0.04697), and DRC with ++ to +++ enlarged nuclei (P = 0.03333), and pleomorphic nuclei (P = 0.00833). Two of the three cytologically diagnosed DRCS cases proved to be MBC or MBC-like and one as invasive ductal carcinoma. Six of nine cytologically diagnosed MBC cases with histology proved to be invasive breast carcinomas. CONCLUSION: Criteria for cytodiagnosis MBC need a fresh look. Cases with numerous dendritic cells possibly represent MBC.

T-cell-rich B-cell lymphoma (TCRBCL): limitations in fine-needle aspiration cytodiagnosis.

Exclusive reports on fine needle aspiration (FNA) cytodiagnosis of T-cell-rich B-cell lymphoma (TCRBCL) are scarce in literature. This report reflects the diagnostic difficulties associated with cytodiagnosis of this rare variant of diffuse large B-cell lymphoma. The study is based on 11 cases with age ranging from 16 to 63 years and a median of 50 years. Male to female ratio was 6:5. Ten cases presented with lymphadenopathy and one had lymphadenopathy as well as extranodal solid tumor. The initial cytodiagnosis was suggestive of TCRBCL in one case, TCRBCL/Hodgkin's lymphoma (HL) in three cases, TCRBCL/HL/anaplastic large cell lymphoma (ALCL) in two cases, TCRBCL/ALCL in one case, and TCRBCL/non-Hodgkin lymphoma (NHL) T-cell/ALCL in one case. There was also a cytologically diagnosed HL case, which on review turned out to be HL/TCRBCL. Histopathological diagnosis was HL in all these nine cases. There were two histologically diagnosed TCRBCL cases during this period, with cytodiagnoses of NHL other than TCRBCL in one and HL in the other. While highlighting the difficulties associated with the cytodiagnosis of TCRBCL, this study conveys a word of caution that adequate immunocytochemical studies should be performed before diagnosing this rare neoplasm with a varied cytomorphology.