Tumor composed of fascicles or whorly bundles of proliferating bland looking spindle cells with fusiform or blunt ended (cigar-shaped) elongated nuclei. There is focal palisading of nuclei. Anaplasia is mild and mitosis is not active. Tumor is seen attached to serosal surface of ileal loop with free resection margins.
Given age, main possibility for this tumor is smooth muscle tumor. However, for definitive excluding of other possibilities of gastrointestinal stromal tumor (GIST) and peripheral nerve sheath tumor. Marker study (CD117, Dog-1, CD34, SMA, S100 and Ki-67) is recommended for definitive typing and assessment of exact biologic behaviors.
Pelviabdominal mass attached to antimsenetric border of ileum.
Single encapsulated soft tissue mass measuring 14.5 x 8 x 7.5 cm, with an attached segment of terminal ileum measuring 1.5 x 2.0 cm. Serial sectioning revealed a solid, firm mass with a gray cut surface measuring 14 x 7.5 x 7 cm. On opening of ileal segment, there is no evidence of mucosal polyps or tumors. The solid tumor mass approaches to within approximately 0.9 cm of the terminal ileum margin.
Pelviabdominal mass attached to ileal segment, excision: