Solitary Fibrous Tumor of the Central Nervous System: A Report of Two Cases with Emphasis on Diagnostic Pitfalls.

Solitary fibrous tumor (SFT) is a rare primary central nervous system neoplasm that usually presents as a dural-based mass. Awareness of the entity is limited by the rarity of the tumor which renders it prone to misdiagnosis. We present two cases of SFT located in the right parafalx and intraventricular region. The cases were classified as WHO grade 1 and grade 2, respectively. The present study discusses the radiological, histomorphological, and immunohistochemical features of SFT, with emphasis on potential diagnostic pitfalls that may lead to erroneous diagnosis.

Clinicopathological Review of Human Coenurosis in Kwazulu-Natal, South Africa: A Retrospective Single Center Study.

Background: To describe the clinicopathological features of human coenurosis diagnosed at a single center in an academic Anatomical Pathology Laboratory, KwaZulu-Natal, South Africa. Methods: This was a 10-year retrospective laboratory based study, from 2011-2020, which reappraised the clinical presentation, histomorphological tissue reaction patterns and outcomes in patients diagnosed with coenurosis. Results: Five cases of coenurosis and 19 cases of cysticercosis were diagnosed during the study period. Following re-appraisal of the slides, 6 cases of coenurosis were confirmed and included in the study cohort. The anatomical distribution of disease was as follows: brain (1), liver (1), eye (1) and soft tissue (3). There were 3 males and 3 females and the patients' age ranged from 2 to 46 (mean 22.2) yr. Three patients were HIV positive whilst the clinical history of the infection was not available for the other 3 patients. All patients presented with mass effect related symptoms, ranging from headache to a painful soft tissue swelling. Two cases displayed synovial metaplasia in addition to characteristic chronic subacute inflammation and fibrosis. One case had supportive inflammation. Two cases comprised of coenuri exclusively and therefore it was not possible to assess tissue reaction. Conclusion: We describe the first cases of human coenurosis in HIV positive patients and for the first time report synovial metaplasia as one of the reaction patterns of coenurosis. Whenever cysticercosis and hydatidosis are considered clinically, a negative serology should prompt clinicians to consider coenurosis in addition to the neoplastic diagnostic considerations.

Histoplasma capsulatum var. duboisii: A KwaZulu-Natal, South Africa public sector perspective.

BACKGROUND: Histoplasma capsulatum var. duboisii (H. duboisii) causes potentially fatal disease in the immunocompromised patient, and the literature on these cases is limited. The study was undertaken to describe the cases of H. duboisii seen in a resource-limited setting. METHODS: A 5-year retrospective, laboratory-based histopathologic review of all H. duboisii cases. RESULTS: A total of 24 patients were diagnosed with cutaneous H. duboisii infection. The male-to-female ratio was 1.4. All the patients were human immunodeficiency virus (HIV) positive, and 70.83% (17 of 24 patients) were on antiretroviral therapy. The clinically identified lesions were as follows: plaques, nodular plaques, papules, papulo-pustules, and umbilicated papules. Histopathological appraisal revealed organisms typical of H. duboisii. The commonest epidermal alterations were interface change, parakeratosis, spongiosis, ulceration, acanthosis, hyperkeratosis, transepidermal elimination, and exocytosis in decreasing order. The dermal changes included histiocytic pattern (n = 14), neutrophil-rich (n = 13), non-necrotizing granulomatous inflammation (n = 9), and karyorrhexis (n = 6). Histoplasma was confirmed in 53% (8 of 15 samples) of the tissue samples submitted for routine fungal culture. CONCLUSION: This study showed the demographics, clinical and histopathology features of H. duboisii infection in a resource-limited setting. Further research on histopathological features of this rare infection is essential to expand on the knowledge base and support findings in this study.

Gastrointestinal Tract Plasmablastic Lymphoma in HIV-Infected Adults: A Histopathological Review.

BACKGROUND.: Plasmablastic lymphoma (PBL) is an aggressive B-cell lymphoma that is characterized 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 have been reported. In the current study, morphologic, immunohistochemical, and molecular features of 17 cases of gastrointestinal tract PBL were reviewed. METHODS.: Ten-year retrospective study that reappraised the histomorphological and immunophenotypical profiles of HIV-associated PBLs in the gastrointestinal tract. RESULTS.: The mean age of the study patients was 41 years with a 3:1 ratio of males to females. The most common site of tumor origin was the small intestine (42%), followed by the stomach (29%) and the colon (29%). Majority of the cases showed a predominant diffuse (82%) growth pattern. Immunoblasts and plasmablasts were observed in all cases. Plasmacytic differentiation was seen in 5 (29%) cases. Additional observations not previously described or emphasized in literature includes pseudo-alveolar growth pattern, centroblast-predominance, multinucleated giant cells, and clear cell change. Immunohistochemistry revealed absence of pan B-cell antigens and expression of plasma cell antigens in all cases. Epstein-Barr virus-encoded RNA was expressed in 53% of the cases. CONCLUSIONS.: This study highlights the spectrum of histopathological features seen in gastrointestinal tract PBLs. Awareness of this entity and its histopathological features in the gastrointestinal tract is essential for making a timely and accurate diagnosis and improving patient outcomes.