Involvement of Kaposi's sarcoma in the gastrointestinal tract is common in AIDS patients and can also occur in non-AIDS patients. However, the disease is usually asymptomatic and, due to tumor growth primarily in the submucosa, biopsy diagnosis is possible in less than 25%. In the present study, we describe two cases of Kaposi's sarcoma that were first diagnosed in the gastrointestinal tract of a 74-year-old patient who presented to the clinic with nausea and vomiting. On esophagogastroduodenoscopy, a lesion 0.7 cm in size was found. Histology revealed a Kaposi's sarcoma of the stomach with existing HHV8 infection, and there were negative tests for HIV. The second case is a 39-year-old patient with multiple lesions in the stomach and in the small and large intestine. The histology verified multiple Kaposi's sarcomas that were HHV 8-positive. Afterwards, the diagnosis of an HIV infection was made. Primary diagnosis of Kaposi's sarcoma of the gastrointestinal tract in HIV-negative patients is certainly rare and more frequently made in HIV patients. Nevertheless, Kaposi's sarcoma must always be considered in lesions of the gastrointestinal tract or in gastrointestinal bleeding and should lead to further elucidation of the causes.
"The gastrointestinal (GI) tract is a common site of visceral involvement     , and a definitive diagnosis of GI-KS can be made by endoscopic tissue biopsy   . Histopathologically, GI-KS is characterized by spindle cells that form vascular channels, which fill with blood cells  . Endoscopically, GI-KS has various macroscopic presentations: patches, polypoid lesions, submucosal nodules , bulky masses, and ulcerations [13, 17, 19–23]. "
[Show abstract][Hide abstract] ABSTRACT: 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 (P < 0.01). Small size (<10 mm) and patches found on endoscopy were significantly associated with FNRs (P < 0.05). Findings of submucosal tumor (SMT) with ulceration were significantly associated with true-positive results (P < 0.05). 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.
[Show abstract][Hide abstract] ABSTRACT: The authors deal with the reduction of the order of controllers.
The approach suggested is to introduce an additional dynamic parameter
between the measurement and the control signals, in order to render any
preselected eigenvalues of the given controller unobservable and/or
uncontrollable. Such order-reducing parameters are parameterized in the
Decision and Control, 1988., Proceedings of the 27th IEEE Conference on; 01/1989
[Show abstract][Hide abstract] ABSTRACT: Gastrointestinal Kaposi's sarcoma (KS) may mimic gastrointestinal stromal tumours (GISTs) histologically. Studies have shown that KS outside the gastrointestinal (GI) tract may express CD117, an antibody usually used to support a diagnosis of GIST. The aim was to evaluate the clinicopathological features of GI KS, including the expression of CD117 with and without antigen retrieval.
Fourteen GI KS were assessed histologically, 12 of which were also subjected to immunohistochemistry for CD34, human herpesvirus (HHV) 8, DOG1 and CD117. CD117 immunohistochemistry was performed with and without antigen retrieval. All cases showed an infiltrative spindle cell tumour. Lamina propria infiltration, lymphoplasmacytic inflammation, extravasated red blood cells and haemosiderin were typical histological features. In all cases tumour cells were positive for CD34 and HHV8, but negative for DOG1. CD117 was positive in four of 12 cases without antigen retrieval and 10 of 12 cases with antigen retrieval.
The microscopic distinction of GI KS from GIST can be difficult. Clues that raise the possibility of GI KS include young patient age, a history of immunosuppression, lamina propria infiltration, lymphoplasmacytic inflammation, extravasated red blood cells and haemosiderin deposition. Use of the immunomarkers CD117 (without antigen retrieval), HHV8 and DOG1 may aid in the distinction between GI KS and GIST.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.