‘T HE recent report of Lovelady and Dockertyi on extragenital pelvic tumors has prompted this report of an enterogenous cyst in the pelvic cavity. Enterogenous or enteric cysts are considered to be developmental in origin, there being several theories as to their mode of development. Reports of these growths indicate that of all locations where they have been found, the pelvic cavity is probably the most rare. We have encountered reports of only six enteric cysts occurring in this location in both sexes, five of them posterior and one of them anterior to the rectum.% a, *, 5 No report of a pelvic enterogenous cyst complicating pregnancy has been found in a survey of the twentieth century literature. The patient was a 21-year-old white para 0, gravida i. The last menstrual period was .July 10, 1949. The expected date of confinement was April 15, 1950. Her past history was tessentially noncontributory. There was no history of rectal or pelvic complaints. Physical *examination on Sept. 22, 1949, reevaled no abnormality except in the pelvis. The cervix was slightly dusky, and the uterus was softened and enlarged to the size of an 8 to 10 weeks’ pregnancy. Posterior to the rectum and between it and the lower sacrum and upper coccyx, lying largely to the right of the midline, was a tensely fluctuant, smooth, nontender mass estimated to be about 7 by 7 by 5 cm. There was practically no motility. Although the rectal mucosa could not be freely moved over the surface of the tumor, the wall of the mass and the rectal mucosa did not seem to be adherent. Through the proctoscope the rectum appeared normal. The blood Kahn test was negative, the hemoglobin was 12.4 Gm., the urine was normal. Weight was 131 pounds. The blood pressure was normal. An intravenous pyelogram showed a normal urinary tract. Anteroposterior and lateral x-rays of the bony pelvis showed no anomalies or evidence of bone destruction. The tumor mass was seen as a light shadow of a size and location similar to that noted at the time of initial examination. It was decided to defer removal of the mass until a time less provocative of abortion should be reached. On Jan. 4, 1950, removal of the tumor under spinal anesthesia was effected. The patient was placed prone on the table with a pillow under the upper thighs. A midline incision was made from just above the sacrococcygeal junction to the verge of the anus. The coccyx was removed and the incision was deepened. The lower pole of the tumor presented in the fat of the right ischiorectal space. It was dissected free by blunt dissection without difficulty. Although it was ruptured as the upper pole was being freed, the wall was easily distinguished from the adjacent tissues and removed without difficulty. The contents had the appearance of old pus but were odorless. No important nerves or blood vessels were encountered; the operation was almost bloodless. The wound was very loosely and incompletely closed over a soft rubber tissue drain. It healed uneventfully in about five weeks. The patient was out of bed on the day following operation and was discharged on the third postoperative day. The remainder of pregnancy was normal. After an uneventful labor, she was delivered by low forceps on April 20, 1950. A right mediolateral episiotomy healed by primary intention. Pathologist’s Report.-Submitted was a cystic structure measuring 2.8 by 1 by 0.8 cm. The outer surface was smooth and mottled and glistening. The cystic structure had been incised and there was evidence of a dark-staining, mucoid material present. The cyst wall