Congenital or torsion-induced absence of Fallopian tubes. Two case reports.

Unilateral absence of a uterine tube is an extremely rare finding, for which there are two possible etiopathogenic causes: in some cases it is due to haemorrhage filling of the cavity and its reabsorption as a result of asymptomatic torsion of the uterine tube during adult life, in pediatric age or even during intrauterine life; alternatively, the absence may be congenital, associated with developmental alterations of the mesonephric and paramesonephric ducts. The article presents two cases of fallopian tube absence: a congenital monolateral absence and a tubal torsion during pregnancy. The symptomatology of the torsion of the fallopian tube in pregnancy can be milder than in the classic description with peritoneal reaction and severe clinical alteration. The main risk factors for tubal torsion are: adhesions and inflammatory processes, ovarian cysts, usually of dermoid type, menstrual period, pregnancy, abnormal long mesosalpinx and/or mesovarium, pelvic congestion induced by constipation and disturbed venous blood flow from the adnexa. A congenital defect of the mesonephric duct is followed by a homolateral defect of the paramesonephric duct. The resulting anomaly is characterized by the absence of the uterine tube, uterus-tube angle, kidney and ureter. Partial or total unilateral defects of a paramesonephric duct are more common than aplasia of both ducts. Some authors have suggested that an inadequate blood supply during the descent into the pelvis of the caudal part of the paramesonephric duct might feasibly lead to incomplete tube development.