Histological and clinical outcome of a novel case of perineal hamartoma, atresia ani, and rectovaginal fistula in female Holestein calf

The association of anorectal congenital malformation and perineal mass are extremely rare at veterinary literature. The present report is a novel case of perineal hamartoma, atresia ani, and rectovaginal fistula in female calf, 2-day-old female Holstein Friesian calf. The animal had a fleshy, dark red, trailing perineal mass at the left side, imperforated anus and about 1 cm rectovaginal fistula. Imperforated anus and rectovaginal fistula were surgically corrected. The mass was firm, red in color and contain bean-shaped, white color tissues on cut section. It was misdiagnosed as teratoma, but the careful histological examination revealed disorganized mature fibrovascular tissue, mature adipose tissue, blood vessels, neural tissue. In addition to urogenital epithelium diagnosed as remnants of Mullerian duct, and the mass was diagnosed as perineal hamartoma, associated with atresia ani type II and rectovaginal fistula. To the best of our knowledge, this is the first perineal hamartoma, atresia ani, and rectovaginal fistula in Holestein Friesian calf with proper outcome upon surgical interference.