Multiple glomus tumors of the stomach with intravascular spread.

Gastric glomus tumors are characteristically benign solitary lesions. We present a case of multiple glomus tumors involving the stomach wall and perigastric adipose tissue. Histologically, the major portion of each tumor was composed of "typical" glomus cells arranged in a predominantly solid pattern. Cavernous hemangiomalike areas were present toward the periphery. The tumor cells were immunoreactive for alpha-smooth muscle actin, vimentin, laminin, and type IV collagen, but did not express desmin. There were several focal areas where the tumor cells had a signet-ring cell-like appearance, intermingled with cells having clear cytoplasm and hyperchromatic nuclei. Rare mitoses were noted. A striking feature was the presence of widespread but subtle extension of the glomocytes along venous channels subendothelially, with formation of intravascular nodules focally. The multiple separate tumor nodules found in perigastric fat are interpreted as having arisen in this manner. This entity is distinct from previously described typical and atypical solitary glomus tumors, glomangiosarcoma, and the syndrome of multiple glomus tumors of subcutaneous tissues. It may represent an early stage of development of the large, multilobulated glomus tumors that have rarely been reported to involve stomach and adjacent viscera.