1845 BACKGROUND: Extraintestinal infestation by Enter- obius vermicularis is uncommon. It has been reported to occur in the peritoneal cavity, ovary, fallopian tube, endometrium, lung, liver and urinary tract. CASE REPORT: Fine needle aspiration diagnosis was made in a case of enterobiasis presenting with a subcuta- neous abscess in the natal cleft. Eggs, as well as frag- ments of cuticle of the adult worm, were found; the mor- phology of both was best vi- sualized in Papanicolaou-stained smears. Polarizing mi- croscopy highlighted the equally spaced parallel grooves of the cuticle. CONCLUSION: Fine needle aspiration cytology of sub- cutaneous abscesses due to enterobiasis can be diagnostic when eggs, or eggs with cuticle, are identified in a sup- purative or granulomatous inflammation. (Acta Cytol 1997;41:1845–1847) Keywords: Enterobius vermicularis, aspiration biop- sy, abscess. Enterobiasis (pinworm, or threadworm, infestation) is a common worldwide disease of both children and adults. During the evening hours, the gravid female worm migrates from the lumen of the cecum, its normal habitat, to the perianal area to de- posit eggs. The usual man- ifestations are distressing irritation and perianal pruritis. However, of greater importance are the un- common clinical manifestations attributed to mi- gration of the worm to distant sites, 3,4,6,9,11,13,15,18 including the peritoneal cavity, ovary, fallopian tube, endometrium, lung, liver and urinary tract. The diagnosis of intestinal infestation is based on detection of adult worms, often discovered in the From the Cytology Section, Department of Pathology, University College of Medical Sciences and Guru Tegh Bahadur Hospital, Delhi, India. Drs. Arora and Singh are Readers. Dr. Chaturvedi is Resident. Dr. Bhatia is Professor. Address reprint requests to: V. K. Arora, M.D., Cytology Section, Department of Pathology, University College of Medical Sciences, Delhi 110 095, India. Received for publication October 15, 1996. Accepted for publication January 16, 1997. Fine Needle Aspiration Diagnosis of a Subcutaneous Abscess from Enterobius vermicularis Infestation A Case Report V. K. Arora, M.D., Navjeevan Singh, M.D., Sujata Chaturvedi, M.D., and Arati Bhatia, M.D. Acta Cytologica 0001-5547/97/4106-1845/$02.00/0 © The International Academy of Cytology Acta Cytologica This report highlights the cytologic diagnosis of enterobiasis with an unusual presentation as a subcutaneous abscess in the natal cleft. DO NOT DUPLICATE © Copyrighted Material