Malignant Glomus Tumor of the Peritoneum: Case Report
A screening gynecological exam was performed in a 47-year-old woman. The bimanual pelvic exam revealed the presence of bilateral parauterine masses. These masses were partially mobile and poorly demarcated. Transvaginal ultrasound showed a right parauterine mass of 11.9 × 4.7 cm and a left one of 13.2 × 7.9 cm. The masses were heterogeneous with irregular margins and were barely vascularized, which encompassed the left ovary and fallopian tubes. No free liquid was observed. A double phase contrast-enhanced multidetector computed tomography (CT) scan was performed with the intravenous injection of 120 mL non-ionic contrast medium at flow rate of 4 mL/sec. The CT exam, which included a late arterial phase of the thorax and abdomen followed by a portal phase of the abdomen and pelvis, revealed a poorly defined mass occupying the inframesocolic peritoneal space and both paracolic gutters. This mass showed extensive low-density areas (with CT density values around 25 Hounsfield units [HU]) with interspersed foci of higher attenuation (approximately 50 HU) and some small calcifications (). The CT examination did not reveal any significant changes in tumor density between both phases of the acquisition. Laboratory tests evidenced high levels of CA125 antigen. An exploratory laparotomy was performed. Intraoperative findings demonstrated a poor-defined abdominopelvic soft tissue mass with extensive areas of necrosis attached to the parietal peritoneum, the visceral peritoneum of the uterine fundus, terminal ileum loops and umbilicus. The remainder of the abdominal cavity including the gastrointestinal tract and ovaries was normal. Macroscopically, the resected specimen was a large peritoneal tumor measuring 45 × 30 cm in diameter, with a smooth surface, shiny, very congestive and hemorrhagic. After cutting, heterogeneous brittle and frayed hemorrhagic areas were identified without a definite pattern. Microscopically, the mass had abundant capillary-sized vessels, which had small round to dilated endothelium-line lumina surrounded by uniform sheet-like epitheloid tumor cells. Immunohistochemically, vimentin, (alpha)-smooth muscle actin, HHF-35 actin and collagen IV were stained intensely (). Tumor cells were negative for desmin, CD31, CD34, cytokeratin AE1/AE3, melan-A and HMB 45. Finally, the pathologic diagnosis was peritoneal GMS. One year later, the patient remains asymptomatic without radiologic evidence of tumoral recurrence.