Elderly Male with Submucosal Gastric Mass
Elderly Male with Submucosal Gastric Mass
Anna Savin, M.D., Roula Katerji, M.D.
Clinical History
An elderly male with a history of ulcerative colitis and prior right hemicolectomy was found on computed tomography (CT) to have a 1.7 × 1.5 × 1.2 cm enhancing nodule in the posterior wall of the gastric antrum. Subsequent esophagogastroduodenoscopy (EGD) with endoscopic ultrasound demonstrated a mural gastric lesion arising from the muscularis propria. Deep biopsies were obtained for further evaluation.
Microscopic Findings
Histologic sections show a well-circumscribed nodular proliferation of uniform round cells with bland nuclei and abundant eosinophilic cytoplasm, embedded in a hyalinized stroma and intimately associated with variably sized capillary-type vessels (Figures 1–3). No significant cytologic atypia, necrosis, or mitotic activity is identified.
Immunohistochemical studies demonstrate diffuse positivity for smooth muscle actin (SMA) (Figure 4), while the tumor cells are negative for pancytokeratin, synaptophysin, chromogranin, DOG1, and c-KIT. The Ki-67 proliferation index is low (<1%) (Figure 5).
