The use of computed tomography in the diagnosis of abdominal cocoon

Literature on the diagnosis of abdominal cocoon using computed tomography (CT) outside the setting of continuous ambulatory peritoneal dialysis is sparse.

We did a retrospective analysis of contrast enhanced CT done for patients treated for abdominal cocoon. The clinical features, radiological findings, underlying etiology and outcomes were recorded.

Of the 22 patients analyzed, 19 had tuberculosis, 2 had malignancy and 1 was idiopathic. The basis of diagnosis of cocoon was CT in 18 and CT and surgery in 4. Types 1, 2 and 3 cocoon were found in 3 (13.63%), 6 (27.27%) and 13 (59.09%) respectively. The bowel findings were clumped loops in 21 (95%), inter-bowel fluid in 13 (59%), bowel wall thickening/enhancement in 6 (27%) and stricture in 1 (5%). Peritoneal thickening and nodularity were seen in 14 (64%) and 2 (9%) while omental thickening, nodularity and mass in 9 (41%), 5 (21%) and 1 (5%). Cauliflower sign was seen in 14 (64%), concertina pattern in 5 (23%) and Bottle Gourd sign in 6 (23%) patients. Of 12 with imaging done during episode of IO, 11 (92%) had cauliflower sign, 4 (80%) had concertina appearance and 6 (100%) had bottle gourd sign. Post treatment weight gain with anti-tubercular therapy was seen in 14 (63.63%), resolution of ascites in 12 (54.54%) and 2 patients had complete resolution of cocoon on repeat imaging.

CT is a valuable tool for pre-operative diagnosis of abdominal cocoon. The classical described signs are seen more frequently in patients with IO.