Encasement of a variable length of small intestine by a fibrous membrane, usually presenting as intestinal obstruction, and/or, an abdominal mass, was first described as an abdominal cocoon in 1978 [1]. A search of the literature has revealed thirteen cases [1][2][3][4], and an additional case was reported as peritoneal encapsulation [5], which is more likely to have been an abdominal cocoon. This results in a total of fifteen cases, including our own, are discussed in this study.
Case ReportA 26-year-old female, who was 25 weeks pregnant, was admitted to this hospital complaining of colicky abdominal pain in the right iliac fossa of two days duration, accompanied by nausea without vomiting.She gave a history of recurrent attacks of similar, but less severe, pain during the five years prior to this attack. Her menstruations were reported as very painful, but regular. There was no other relevant medical or drug history. On examination her pulse was 88 per minute, her temperature was 37.1°C, and abdominal examination revealed tenderness in the right iliac fossa. The size of the uterus corresponded with the date of her last menstrual period 25 weeks ago. Fetal heart sounds were regular, and 135 beats per minute. No abnormality was detected on routine urine testing. The WBC was 14000 cells per cubic millimeter. The pain became more severe in the following two hours; her pulse rate rose to 94 beats per minute; her temperature rose to 37.5°C; she vomited; and her WBC rose to 16000 cells per cubic millimeter. It was felt that an appendectomy should be performed.However, through a right McBurney incision, the appendix looked normal. The right fallopian tube, ovary and the uterus also showed no sign of gross pathology. When the terminal ileum was brought out of the wound, a membrane was found to be encasing the distal 30-40 cm of it, sparing only the ileocecal junction area with two openings in the membrane for the afferent and efferent small intestine, which was distended proximally. The pelvic surface of the sac, which was thicker than other surfaces, was studded with minute brownish spots. The membrane was dissected off the intestine, and its mesentery, with slight difficulty. Then the appendectomy was performed.Postoperative progress was uneventful. Three months later the patient had a normal delivery, giving birth to a healthy female infant. She reported that her periods were not as painful as before, and her last surgical and obstetric exam, six months later, revealed no abnormalities.
PathologyThe appendix was normal. Sections taken from the tissue submitted for histopathology showed fibrovascular tissue admixed with mature adipose tissue. No inflammatory cells were present. However, selective sections taken from the scattered minute brown focci revealed glandular structures lined by a single layer of low columnar epithelium and surrounded by large cells with distinct borders and granular pink cytoplasm (decidua-like cells). There were few foci of hemosiderin laden macrophages (Figures 1, 2). No trophoblastic tiss...