Vesical dermoid: An unusual presentation

Dermoid cysts are considered developmental anomalies and consist of tissue from more than one germ cell layer. They occur most commonly in the ovaries, but might also be found at other sites, especially in the midline. Dermoid cysts are particularly rare in the urinary bladder. We herewith present one such case. A 26-year-old woman presented with complaints of the passage of hair in her urine for the past 2 years associated with two episodes of gross hematuria. She had no other genito-urinary or bowel complaints. The clinical, routine blood and urine examinations were normal. An ultrasound of the abdomen showed an irregular, echogenic lesion measuring 5.6 ¥ 6 ¥ 5.3 cm within the lumen of the urinary bladder. On trans-vaginal sonography, both ovaries and the uterus were found to be normal. Cystoscopy showed a 5 ¥ 5 cm mass arising from the dome of the urinary bladder with multiple hairs projecting from it. Computed tomography showed a well-defined lesion in the urinary bladder measuring 5.2 ¥ 3.1 ¥ 4.5 cm showing variegated attenuation of fat, soft tissue and bone. The patient underwent open surgery through lower midline incision. A 6 ¥ 5.5 cm mass was found to be arising from the right posterolateral wall of the bladder. It was covered with skin and hair on its surface. A tooth was also seen arising from the mass. The right ovary, which appeared normal on inspection, was densely adherent to the bladder wall at one of its poles. The intravesical mass was excised with a 1-cm rim of normal bladder mucosa, and right salpingo-oopherectomy was carried out because the ovary could not be separated from the bladder wall (Fig. 1). The bladder was repaired in two layers. The patient had an uneventful recovery. The histopathology report showed a mature teratoma with ectodermal, mesodermal and endodermal elements. The teratoma was reported to be confined to the bladder wall with no extension outside. The excised right ovary and tube did not reveal any pathology. Dermoid cysts are developmental anomalies and are considered teratomas. Leblanc in 1831 coined the term dermoid cyst when he removed a lesion at the base of a horse’s skull, which he called a “kyste dermoid”. Developmentally, dermoid cysts are a result of the sequestration of skin along the lines of embryonic closure that contain mature skin complete with hair follicles and sweat glands, sometimes clumps of long hair, and often pockets of sebum, blood, fat, bone, nails, teeth, eyes, cartilage and thyroid tissue. Because it contains mature tissue, a dermoid cyst is almost always benign. Dermoid cysts are rare in the urinary bladder and can pose a diagnostic problem. A review of the literature revealed just nine reported cases. The passage of hair in the urine (pilimictia) is a pathognomonic sign of urinary bladder dermoid. The origin from primordial germ cells is now the most widely accepted theory of pathogenesis of dermoid cysts. Dermoids are recognized as often being trigerminal and containing practically any type of tissue. The treatment should be conservative considering the benign nature of the entity.