Exophytic inflammatory myofibroblastic tumor of the stomach in an adult woman: a rare cause of hemoperitoneum

Abstract

Inflammatory myofibroblastic tumor (IMT) of the stomach in adults is extremely rare, with unpredictable prognosis. We present a 55-year-old woman with a gastric IMT. She experienced sudden abdominal pain 4 d previously. Physical examination showed mild abdominal tenderness in the hypogastrium, but no palpable abnormal abdominal mass. Abdominal CT showed a mass of approximately 8 cm in the gastrocolic ligament. On laparoscopic exploration, unexpected hemoperitoneum of approximately 1.5 L of blood was found, and an exophytic gastric mass of approximately 10 cm, appeared from the anterior wall of the gastric body along the greater curvature. Laparoscopy further showed that non-clotting blood in the abdominal cavity seemed to be from the gastric tumor. After conversion to open surgery for more precise evaluation of the cause of hemoperitoneum and the large friable tumor, gastric wedge resection, including the tumor, was conducted. The final diagnosis was consistent with IMT that originated from the gastric wall.

Figure 1

Abdominal CT revealed a large solid mass at the gastrocolic ligament or the gastric wall, which showed heterogeneous density on an non-enhanced image (A). The 8 cm mass showed internally enhanced vessels on the arterial phase of CT and delayed peripheral enhancement of the mass on the venous phase (B-D).

Figure 2

Contrast-enhanced MRI of the abdomen showed a mass of approximately 8 cm, seen at the left upper quadrant of the abdomen. The margin of the mass was lobulating, and it was attached to the greater curvature of the stomach. It contained a peripheral enhanced solid portion and a central non-enhancing portion (A). Signal intensity of the central non-enhancing portion was low on T1WI (B) and T2WI (C and D), which suggested internal hemorrhage within the tumor.

Figure 3

Laparoscopic view of the exophytic gastric mass with a large amount of intra-abdominal non-clotting hemorrhage.

Figure 4

The external surface of a well-encapsulated lump of soft solid tumor, weighing 88.1 g, was smooth and glistening, but showed no gastric mucosal lesion (A). Cross-sectional surface of the tumor was characterized by several amorphous fragments of parenchymal tissue, which were separated by the cystic spaces (B).

Figure 5

A: The tumor was composed of round and spindle-shaped myofibroblastic cells. Diffusely scattered inflammatory cells and many vascular structures are seen (HE, × 400); B: The tumor cells showed positive immuno-reactivity for vimentin (× 400).