Case reportA 32-year old man complained of a painless swelling in the left groin, of 4 months duration. Examination showed a non-tender, irreducible mass in the left inguinal region. The external genitalia were normal. A diagnosis of incarcerated inguinal hernia was made, and the patient was therefore admitted for early operation.Via an inguinal incision, the spermatic cord was easily mobilised from the presumptive direct inguinal hernia. It became clear, however, that the 'hernial sac' was in fact a thin-walled cyst, 8.5 x 6 ern, containing pultaceous material. The cyst protruded beneath the conjoint tendon, and had originally extended to the superficial inguinal ring (Fig 1). HistologyThe cyst wall was composed of squamous epithelium, with hair follicles, sebaceous glands, and apocrine sweat glands (Fig 2, apocrine glands at top right).These findings are characteristic of a sequestration dermoid, formed when ectodermal fu-