A primary retroperitoneal mucinous tumor of low malignant potential

초록

We report an extremely rare case of ovaria like mucinous tumor of low malignant potential originating in the retroperitoneum of 35 year old woman otherwise normal gynecologic status. A 35 year old woman admitted for evaluation of a palpable abdominal mass which had apparently been growing for four months. The patient complained of epigastric discomfort and dyspepsia. Physical examination revealed a large, nontender mass in the right quadrant of the abdomen. At operation, a large retrotperitoneal cyst was found lateral to psoas muscle. No other abnormality was noted in the peritoneal cavity, including the ovaries and uterus. The surgical specimen consisted of an intact cyst, measuring 13.0x8.0x5.0cm, with a smooth external surface. On section, the cyst was unilocular and contained brownish dirty fluid and necrotc tissue fragment. The internal cyst wall was for the part smooth, except for nodular excrescence, measuring 4.5x3.5x2.0cm. Hisdtologic section revealed that the cyst wall was lined by a single layer of tall columnar epitheliaum, with clear mucus containing cytoplasm and basally located nuclei. Crresponding to the nuocular area, the epithelium displayed stratification and moderate cellular atypia with filliform papillae. There is no evidence of stromal invasion. This case had ovarian type stroma in its wall, suggesting the possibility of an origin from supernumeray ovary located in extraovarian site.