Ectopic fingerlike structure in the thoracic region. Case report.
The authors present a case of a rare cutaneous lesion resembling a human finger that protruded from the posterior thoracic region of a 7-month-old girl who was examined after the fingerlike protrusion was noted at birth. The protrusion measured 3 cm in length and 1 cm in diameter. It was located at the level of T-12 and was surrounded by angiomatous and lipomatous tissue. A computerized tomography scan demonstrated three bones in the protrusion. including deformities of the T-9 and T-10 and T-11 dysraphism. Magnetic resonance imaging revealed a hyperintense signal on the T1-weighted sequence and a hypointense signal on the T2-weighted sequence, which was visualized at the attachment to the spinal cord from T9-11. After removal of the fingerlike structure and subcutaneous mass, a T10-11 laminectomy and removal of the intradural mass were performed. Histological examination showed that the appendage was composed of nail, three bones, cartilage, and normal skin. This appendage can be recognized not only as a variant type of caudal appendage but as an ectopic finger and fingernail. The authors discuss the developmental differences among the protrusion in the present case and ordinary caudal appendages.