No abstract

Thromboangiitis obliterans (TAO) is an inflammatory, nonocclusive, and nonatherosclerotic vascular disease. It commonly affects arteries, veins, and surrounding neural elements and is directly related to smoking. Although distal vessels of lower and upper extremities are the most commonly involved, other vessels such as intestinal arteries can be rarely affected. The authors describe a 41-year-old white male smoker who presented with abdominal pain for 3 months and developed an acute bowel ischemia. He underwent urgent surgery, and segmental enterectomy was performed. Histopathologic findings were suggestive of TAO, showing typical involvement of small-sized veins and arteries with intact internal elastic lamina, preserved media, a local nonspecific inflammatory reaction, with new and older arterial and venous thromboses associated. Although mesenteric arteries are seldom injured by TAO, this diagnosis must be considered when the usual causes of intestinal ischemia are ruled out. In this case, even without any other clinical symptoms of TAO, this rare diagnosis could be made.

CD95 (Fas/APO-1)-mediated apoptosis plays an important role in immunological regulation and is related to the pathogenesis of autoimmune diseases. Immunoexpression of CD95 has been reported to frequently occur in low grade non-Hodgkin lymphomas, especially of post-germinal center histogenesis, among which those originating in mucosa-associated lymphoid tissue (MALT lymphomas). However, there is no report comparing in situ immunoexpression of this marker in lymphomas and the hyperplastic lymphoid reaction (chronic gastritis) related to Helicobacter pylori infection. The purpose of the present research was to compare the intensity of lymphoid CD95 immunoexpression in 15 cases of H. pylori-related chronic gastritis and 15 gastric MALT lymphomas. CD95 (anti-CD95) was detected by an immunoperoxidase technique in paraffin sections using the catalyzed amplification system. Graduation of reaction intensity (percentage of CD95-positive cells) was semiquantitative, from 1+ to 4+. Nine cases of chronic gastritis were 4+, five 2+ and one 1+. Three lymphomas were 4+, three 3+, four 2+, four 1+, and one was negative. Although 14 of 15 lymphomas were positive for CD95, the intensity of the reaction was significantly weaker compared to that obtained with gastric tissue for patients with gastritis (P = 0.03). The difference in CD95 immunoexpression does not seem to be useful as an isolated criterion in the differential diagnosis between chronic gastritis and MALT lymphomas since there was overlapping of immunostaining patterns. However, it suggests the possibility of a pathogenetic role of this apoptosis-regulating protein in MALT lymphomas.