[Clinicopathological analysis of aggressive angiomyxoma of soft tissue in abdomino-pelvic cavity].

Aggressive angiomyxoma is a rare mesenchymal tumor. To discuss the clinicopathological characteristics, treatment and prognosis of aggressive angiomyxoma, four cases of aggressive angiomyxoma of soft tissue in abdominopelvic cavity were collected from January 2015 to August 2017 in Peking University International Hospital. The clinical data, imaging examination, histopathological features, immunophenotype, therapy and prognosis were analysed. The related literatures were reviewed. All of the patients were adult females, age range from 27 to 49 years and mean 33 years. The clinical complaint was abdominal distention with no definite predisposing factor, or occasional physical-exam finding with no obvious discomfort. Three cases were primary and one case was recurrent. Typical layered or swirled structural sign was presented by CT and MRI scanning of three cases. All tumors located in the pelvic cavity, and attached to the uterus, vagina, rectum, bladder or ureter. One case was involved in the abdominal cavity simultaneously,adhesive to the spine, inferior vena cava and spleen. The gross appearance of tumors was from 5 to 22 cm in maximum diameter. The sectioned surfaces were soft, solid, white or yellow-gray, focally accompanied by edema, mucoid degeneration or cystic change. Microscopic observation showed that tumor cells were short spindle shaped and little atypical, the stroma was loose like edematous mucus or collagen, and the vessels were rich in thin and thick-wall. Partially the vessel wall expressed hyaline degeneration. Also tumors might infiltrate surrounding tissue, such as fat or nerve. The immunohistochemistry results of all cases were estrogen receptor and progesterone receptor diffusely moderate positive, Desmin and smooth muscle actin mostly positive, whereas CD34 expressed only in vessel and S-100 protein, CD117 and Dog1 all negative. All the tumors were complete surgical excision. During follow-up, one case recurred the second time. Our conclusions are the diagnosis of aggressive angiomyxoma is based on pathological morphology supplemented by immunohistochemistry, and the tumor may relapse after surgical resection.