Pathologic quiz case: a retroperitoneal mass in a young woman.

Abstract

A white woman was admitted to our hospital for investigation of severe microcytic anemia. Initial findings included a hemoglobin level of 59 g/L; hematocrit, 0.20; leukocyte count, 1.3 3 109/L; and platelet count, 309 3 109/L. Personal history was unremarkable except for essential hypertension and obesity. A large mass situated in the right flank was found on physical examination. Radiography and endoscopic examination suggested an ulcerated tumor of the upper duodenum. The lesion produced partial intestinal obstruction and displaced adjacent structures. Further studies pointed to the mass being consistent with an ulcerated duodenal leiomyoma, although at this time a biopsy could not be taken due to the risk of hemorrhage. The patient started suffering from abdominal pain and dyspepsia. Removal of the tumor was recommended. Preoperative studies, which included computed tomography and abdominal ultrasonography, demonstrated an 11 3 8.5-cm abdominal mass, supporting the first diagnosis of duodenal leiomyoma. Preoperative biopsy of the duodenum revealed inflammatory elements with no malignancy in the samples retrieved. Surgical exploration revealed a mass located in the retroperitoneum, between the head of the pancreas and the duodenum, infiltrating the superior mesenteric vein and thus precluding local resection. The surgeons believed that the tumor originated in the pancreas rather than the duodenum, although they could not be sure of the origin owing to the size of the mass and because it affected several structures. Surgery was especially complicated owing to venous invasion and the large size of the mass. A gastrojejunostomy was performed, and 4 units of blood were required. There was no involvement of the liver, spleen, or lymph nodes. Five days after the first operation, the patient suffered postoperative complications. On this occasion, surgical reexploration revealed suture dehiscence and fecal peritonitis. The patient developed septic shock and acute renal failure, and she died 4 days later. Our laboratory received an irregular specimen, measuring 4 3 3 3 0.8 cm, and a few small fragments from the mass, measuring 1.5 3 1 3 0.5 cm overall. The surface of the specimen showed hemorrhagic necrosis, and it was surrounded by a well-formed fibrous capsule. The tumor was predominantly solid, showing some areas with a cystic degenerative pattern. On microscopic examination, the compact areas showed uniform small tumor cells, which in the papillary fields surrounded thin stalks of stroma enclosing delicate blood vessels, appearing as pseudopapillae (Figure 1). Tumor cells contained round or oval nuclei with prominent nucleoli,