Department of Surgery, Tokyo Metropolitan Komagome Hospital, Tokyo, Japan.
Int J Clin Oncol. 2009 Dec;14(6):551-4. doi: 10.1007/s10147-009-0890-7. Epub 2009 Dec 5.
Primary squamous cell carcinoma (SCC) of the colorectum is a rare malignancy of unknown etiology and pathogenesis. We report a case of primary SCC of the rectum. A 55-year-old man with a rectal tumor and human immunodeficiency virus (HIV) infection was referred to our hospital. Histopathology of biopsy specimens showed characteristics of SCC. We diagnosed the patient as having primary moderately differentiated SCC of the rectum according to the criteria proposed by Cooper. Human papillomavirus (HPV) DNA was amplified by polymerase chain reaction analysis of unfixed tumor biopsy specimens. In addition, no p53 overexpression or nuclear staining of retinoblastoma protein (Rb) was observed in neoplastic cells by immunohistochemical staining. We suggest from our case that HPV infection following the inactivation of the cellular tumor suppressor Rb and the immune suppression induced by HIV infection play an etiologic role in the pathogenesis of rectal SCC, consistent with the well-established concept of HPV-associated anal carcinogenesis.
直肠原发性鳞状细胞癌（SCC）是一种罕见的、病因和发病机制不明的恶性肿瘤。我们报告一例直肠原发性 SCC。一名 55 岁男性，因直肠肿瘤和人类免疫缺陷病毒（HIV）感染就诊于我院。活检标本的组织病理学显示 SCC 的特征。根据库珀（Cooper）提出的标准，我们诊断该患者为直肠中分化 SCC。通过对未固定肿瘤活检标本的聚合酶链反应分析，扩增人乳头瘤病毒（HPV）DNA。此外，通过免疫组织化学染色，在肿瘤细胞中未观察到 p53 过表达或视网膜母细胞瘤蛋白（Rb）核染色。我们从该病例中提出，HPV 感染在细胞肿瘤抑制因子 Rb 失活以及 HIV 感染引起的免疫抑制之后发挥作用，导致直肠 SCC 的发病机制，这与已确立的 HPV 相关肛门癌发生的概念一致。
