[CD117 contribution in the diagnosis of mesenchymal tumors of the digestive tract]

Gastrointestinal stromal tumor [GIST] is a new distinct entity defined as CD117 or c-kit positive mesenchymal tumors, originaling in gastrointestinal pacemaker cells known as interstitial cells of Cajal. This study evaluate the percentage of GIST previously diagnosed as mesenchymal tumors in our hospital during 11 years. A total of 30 surgically resected gastrointestinal tumor specimens were collected from January 1990 to December 2000 in the pathology laboratory of La Rabta Jospital. Immunohistochemical studies were performed on these tumors with antibodies of CDI 17, smooth muscle actin [SMA] and protein S-100. Among the 30 tumors, 26 [86.6%] were CD117 positive and were classified as gastrointestinal stromal tumors. Among the 26 GIST, SMA was positive in 11 tumors [42.3%], 6 tumors [23%] expressed protein S- 100. The 4 tumors classified as non-GIST were leiomyomas with the following immunohistochemical characteristics: CD117-negative with strong SMA-positive and protein S100 negative status. The majority [86.6%] of mesenchymal gastrointestinal tumors were GIST, except for a smalls groups of smooth muscle tumors

Dyskeratomie verruqueux ou "Dyskeratomie folliculaire": aspects anatomo-cliniques d'une nouvelle entite

Warty dyskeratoma is a rare, benign, epithelial tumor characterized by a variable clinicopathologic spectrum. In all cases, lesions revealed foci of acantholytic dyskeratosis. Case report: A 74-year-old man has for two year developed a single small nodule with a hyperkeratotic area on the scalp. Histopathology revelead a warty dyskeratoma. Discussion: Warty dyskeratoma is an epithelial tumor. Histopathology is important for the diagnosis. On the basis of our findings and from the literature, we propose to discuss the nosologic problem of this entity