Browsing by Author "Mwazha, Absalom."

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Gastrointestinal tract plasmablastic lymphoma in HIV infected adults: a histopathological audit.
(2020) Mwazha, Absalom.; Nhlonzi, Gamalenkosi Bonginkosi.
Background: Plasmablastic lymphoma (PBL) is an aggressive B-cell lymphoma that is characterised by the expression of plasma cell antigens and loss of pan B-cell antigens. The neoplasm is extensively reported in the oral cavity and anorectal region but rarely in the gastrointestinal tract where only isolated case reports and small case series exist. In the current study, morphologic, immunohistochemical and molecular features of 17 cases of gastrointestinal tract PBL were reviewed. Materials and Methods: Ten-year retrospective study that reappraised the histomorphological and immunophenotypic features of HIV-associated PBLs in the gastrointestinal tract that were diagnosed and coded as ‘plasmablastic lymphoma’. Results: The average age of the study patients was 41 years with a 3:1 ratio of males to females. The most frequent site of involvement was the small intestine (42%). Majority of the cases showed a predominant diffuse (82%) growth pattern. Immunoblasts and plasmablasts were observed in all cases. Sixty-five percent (65%) of the cases exhibited scattered centroblasts and one case demonstrated predominance of centroblasts. Other features observed include pseudo-alveolar growth pattern, plasmacytic differentiation, scattered multinucleated giant cells, focal clear cell change, high mitotic activity with high proliferative indices (Ki-67 >90%), apoptotic bodies and necrosis. Immunohistochemistry revealed absence of pan B-cell antigens and expression of plasma cell antigens. Epstein-Barr virus-encoded RNA was expressed in 53% of the cases. Conclusion: This study highlights the spectrum of histopathological features of gastrointestinal tract PBLs. Additional observations not previously described or emphasised in literature includes pseudo-alveolar growth pattern, centroblast-predominance, multinucleated giant cells and clear cell change. Awareness of this entity in the gastrointestinal tract and its histopathological features and immunohistochemical profile is essential for making an accurate diagnosis and avoiding potential diagnostic errors. Keywords: Plasmablastic lymphoma; HIV-related lymphoma; AIDS-related lymphoma; gastrointestinal tract; stomach; small intestine; colon.
A morphologic and immunohistochemical appraisal of invasive breast carcinomas with neuroendocrine differentiation.
(2021) Naicker, Nimallen.; Nhlonzi, Gamalenkosi Bonginkosi.; Mwazha, Absalom.
Background: Invasive breast carcinomas with neuroendocrine differentiation (IBCNED) are a heterogenous group of tumours first recognised, as a distinct entity, by the World Health Organisation (WHO) in 2003. The classification of these tumours has undergone significant changes since they were first described, and the diagnostic criteria has been inconsistent amongst reporting authors. IBCNED have not been studied in the South African context, and this study aims to review the incidence, demographic profile, histopathology and immunohistochemical profile of IBCNED. Materials and Methods: A three-month retrospective study of cases with the diagnosis of invasive breast carcinomas was undertaken to determine the clinicopathologic profile of IBCNED. Results: The mean age of female patients with IBCNED was 55 years. Thirty-five (35/91, 38%) cases were positive for synaptophysin and/or chromogranin A. The tumours showed a histomorphology comparable with invasive breast carcinoma of no special type and were predominantly (33/35, 94%) moderately to poorly differentiated. The predominant molecular subtype, with 91% (33/35), was luminal B . Conclusion: IBCNED show a diverse range of histomorphologic features, similar to those seen in conventional breast carcinomas of no special type, however they do have distinct cytomorphological characteristics and show a predilection for luminal B molecular subtype. A larger cohort is necessary to confirm these findings and to expand knowledge and treatment options.