Congenital perineal lipoma associated with bilateral undescended testes and anorectal malformation

摘要

The trio of perineal soft tissue tumour, anorectal malformation (ARM) and external genitalia abnormality is exceedingly rare. We present a case of a three-month-old infant who presented with bilateral undescended gonads, ARM and perineal mass. Chromosomal study showed a male profile and ultrasound of his groin suggested right intra-abdominal testis, with the left gonad not visualised. He underwent a period of rectal washouts via the perineal fistula before undergoing elective limited posterior sagittal anorectoplasty. He subsequently underwent left single stage orchidopexy, right first stage orchidopexy and excision of the perineal lump at 10 month of age. Histology revealed lobules of adipocytes with intervening fibrous septae with focal areas of myxoid stroma, suggestive of a lipoblastoma. He then underwent second stage right orchidopexy six month later and no recurrence was noted. Only two cases of perineal soft tissue tumour associated with ARM and external genital abnormality were previously reported. It is likely that the large size of the perineal mass contributed to mal-descent of both testes. We postulate that the constellation of anomalies in our patient falls into the category of the urorectal septum malformation sequence.