Hematocolpos secondary to Imperforate hymen

Pelvic pain in an adolescent girl who has not yet started to menstruate is sometimes explained by imperforate hymen with haematocolpos with or without haematometra. Imperforate hymen is a rare gynecological abnormality that may not be detected until the onset of menses. The symptoms are amenorrhea, recurrent lower abdominal pain and urinary retention [1]. The accumulation of menstrual blood in the vagina and uterus result in hematocolpos that may have pressue effect on the urethra and bladder and lead to the obstructive urinary symptoms. On pelvic examination, bluish bulging hymen may be seen in patients with hematocolpos secondary to imperforate hymen [2]. The diagnosis can be established with the help of abdominal ultrasound by demonstarting fluid with in the vagina and cervix. MRI is an alternate to ultrasound examination and can be performed to have a panromamic view of the pelvis and can also help identify blood within vagina. Blood in vagina contains extracellular methhemoglobin, therefore it is high signal on both T1 and T2 weighted sequences on MRI examination (Figure 2). Imperforate hymen is usually not associated with any other Mullerian abnormalities. The differential diagnosis of Hematocolpos in pubertal developmental stage includes transverse vaginal septum, longitudinal vaginal septum, vaginal agenesis, and cervical atresia [3]. Imperforate hymen can be differentiated from a low transverse vaginal septum by Valsalva maneuver. Imperforate hymen bulges outward with Valsalva and in patients with transverse vaginal septum there is no outward bulge. Magnetic resonance imaging (MRI) can identify the presence of cervix , differentiating cervical agenesis from a high vaginal transverse septum. MRI is considered the gold standard for its diagnosis.