Elias Edrick M, Mwakigonja Amos Rodger
Department of Pathology, Catholic University of Health and Allied Sciences, Mwanza, Tanzania.
Department of Anatomical Pathology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
East Afr Health Res J. 2024;8(3):394-401. doi: 10.24248/eahrj.v8i3.809. Epub 2025 Jan 30.
Treatment and outcome of Kaposi's sarcoma (KS) depend on a correct histopathological diagnosis, however, most KS cases in developing countries are diagnosed clinically without histopathological confirmation, which results in either over or under-diagnosis. Also, due to the number of histopathological mimickers in different stages of KS which include benign to fatal conditions, the histopathological diagnosis of KS is not always correct. However, the HHV-8-LANA-1 Immunohistochemical (IHC) stain is positive in nearly all KS lesions and is considered to be an important diagnostic tool to differentiate KS from its histological mimickers. This study aimed to determine the quality of Kaposi's sarcoma diagnosis at MNH and whether it can be improved by the routine of HHV-8-LANA-1 immunohistochemical stain.
This was a retrospective cross-sectional hospital-based study of all KS cases diagnosed either by clinical, histopathological, or both in 2018. KS was diagnosed based on H&E morphology and confirmed by HHV-8-LANA-1 immunohistochemistry. The diagnosis utility of clinical and histopathology was compared with HHV-8-LANA-1 immunohistochemistry.
There was almost perfect agreement between initial and reviewed histopathology for KS diagnosis (Kappa value= 0.892, ). The clinical diagnosis concordance rate was 61% with no agreement (Kappa value -0.123, ). Clinical differential diagnosis included a wide range of pathological conditions ranging from less severe inflammatory to fatal malignant conditions. There was a substantial agreement between initial histopathology and HHV-8-LANA-1 IHC for KS diagnosis (Kappa=0.70, .000) with a histopathology concordance rate of 88%.
Histopathological examination of all clinical KS suspicions and HHV-8-LANA-1 immunohistochemistry confirmation is required since the study showed that the histopathology misdiagnosis of KS at MNH was unlikely to be the result of human error. We recommend that in every clinically suspected KS case, an adequate tissue biopsy should be taken for histopathology analysis and HHV8-LANA-1 immunostaining to avoid inappropriate treatment.
卡波西肉瘤（KS）的治疗和预后取决于正确的组织病理学诊断，然而，发展中国家的大多数KS病例是临床诊断，未经组织病理学证实，这导致了过度诊断或诊断不足。此外，由于KS不同阶段存在多种组织病理学模仿者，包括从良性到致命的情况，KS的组织病理学诊断并不总是正确的。然而，HHV-8-LANA-1免疫组织化学（IHC）染色在几乎所有KS病变中均为阳性，被认为是区分KS与其组织学模仿者的重要诊断工具。本研究旨在确定蒙巴萨国立医院（MNH）卡波西肉瘤诊断的质量，以及通过HHV-8-LANA-1免疫组织化学染色常规检查是否可以改善诊断质量。
这是一项基于医院的回顾性横断面研究，研究对象为2018年通过临床、组织病理学或两者诊断的所有KS病例。KS根据苏木精-伊红（H&E）形态学诊断，并通过HHV-8-LANA-1免疫组织化学证实。将临床诊断和组织病理学的诊断效用与HHV-8-LANA-1免疫组织化学进行比较。
KS诊断的初始组织病理学和复查组织病理学之间几乎完全一致（Kappa值 = 0.892）。临床诊断符合率为61%，无一致性（Kappa值 = -0.123）。临床鉴别诊断包括从较轻的炎症到致命的恶性疾病等广泛的病理状况。初始组织病理学和HHV-8-LANA-1 IHC在KS诊断方面有实质性一致性（Kappa = 0.70，P <.000），组织病理学符合率为88%。
由于研究表明蒙巴萨国立医院KS的组织病理学误诊不太可能是人为错误导致的，因此对所有临床怀疑为KS的病例进行组织病理学检查并通过HHV-8-LANA-1免疫组织化学进行确认是必要的。我们建议，对于每一例临床怀疑为KS的病例，都应进行充分组织活检以进行组织病理学分析和HHV8-LANA-1免疫染色，以避免不适当的治疗。
