%0 Journal Article
%T False-Negative Results of Endoscopic Biopsy in the Diagnosis of Gastrointestinal Kaposi＊s Sarcoma in HIV-Infected Patients
%A Naoyoshi Nagata
%A Katsunori Sekine
%A Toru Igari
%A Yohei Hamada
%A Hirohisa Yazaki
%A Norio Ohmagari
%A Junichi Akiyama
%A Takuro Shimbo
%A Katsuji Teruya
%A Shinichi Oka
%A Naomi Uemura
%J Pathology Research International
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/854146
%X Kaposi＊s sarcoma (KS) is a rare endothelial neoplasm mainly involving the skin, but it is often associated with AIDS. Diagnosis of gastrointestinal (GI) tract KS, a common site of visceral involvement in AIDS, is important, but endoscopic biopsy carries a risk of false-negative results (FNRs) due to its submucosal appearance. This study sought to determine the rate and causes of FNR for endoscopic biopsy of GI-KS lesions. Endoscopic biopsy samples of 116 GI-KS lesions were reviewed retrospectively. All GI-KS lesions were confirmed to be resolved following KS therapy. FNRs were yielded for 41 of the lesions (35.3%). Among upper and lower GI sites, the esophagus was the only site significantly associated with FNRs ( ). Small size (<10ˋmm) and patches found on endoscopy were significantly associated with FNRs ( ). Findings of submucosal tumor (SMT) with ulceration were significantly associated with true-positive results ( ). In conclusion, FNRs were found in 35.3% of GI-KS lesions and were especially related to the site of the esophagus and endoscopic early stage (small size or patch appearance). An SMT with ulceration may be relatively easy to diagnose on endoscopic biopsy. Caution should be exercised when performing endoscopic biopsy of these lesions in AIDS patients and evaluating the histological features. 1. Introduction Kaposi＊s sarcoma (KS) is a cancer of the lymphatic and blood vessels that mainly involves the skin [1每3]. It is a rare cancer but has become more widely known as one of the AIDS-defining illnesses [2, 3]. Although the rate of AIDS-related KS has decreased dramatically since the introduction of highly active antiretroviral therapy (HAART) [4每6], KS remains the most common malignancy among patients with AIDS [7]. KS can also involve the oral cavity, lymph nodes, and viscera [1每3, 8]. The diagnosis of visceral KS is important because the need for treatment and choosing among the various options depend upon the extent of disease [8每10]. The gastrointestinal (GI) tract is a common site of visceral involvement [11每15], and a definitive diagnosis of GI-KS can be made by endoscopic tissue biopsy [8, 16, 17]. Histopathologically, GI-KS is characterized by spindle cells that form vascular channels, which fill with blood cells [17, 18]. Endoscopically, GI-KS has various macroscopic presentations: patches, polypoid lesions, submucosal nodules, bulky masses, and ulcerations [13, 17, 19每23]. For submucosal nodules especially, endoscopic biopsy sampling has been known to yield false-negative results (FNRs) [17, 23每25]. Some GI-KS lesions might be
%U http://www.hindawi.com/journals/pri/2012/854146/