Imperforate hymen is likely the most common congenital obstructive anomaly in the female reproductive tract. The diagnosis of hydrometrocolpos, or accumulation of fluid in the vagina and uterus, is typically made shortly after birth. The distended hymen presents as a whitish bulge in the posterior introitus and/or a suprapubic mass may be palpable. Whitish vaginal secretions build up in the vagina secondary to maternal estradiol stimulation of the child’s cervical glands. If the diagnosis is delayed after the newborn period, the mucus might be reabsorbed and the bulging hymen no longer evident. If a patient presents in adolescence, it is often with primary amenorrhea, possible cyclic abdominal pain, or a bluish bulging hymen.

Abdominal and pelvic US allows for visualization of the vagina and uterus, as well as the upper urinary tract, which can be obstructed by a dilated vagina (Fig. 21.3). Reimaging is needed to confirm upper tract decompression after an incision of the hymen.

Repair in the newborn consists of a transverse incision of the hymenal tissue. A longitudinal incision would risk injury to the urethra and rectum. Simple aspiration is inadequate as incompletely evacuated material may become infected. In pubertal girls, a hymenectomy of excess tissue may be needed. This condition does not appear to predispose to primary infertility or fetal loss.

A ureterocele is a cystic dilation of the distal ureter. It is classified as ectopic when it extends distal the bladder neck. If it is large enough, an ectopic ureterocele can prolapse through the urethra, making visualization of the meatus and vagina difficult. With time, the mucosa prolapsing through the urethral meatus changes from pink to congested, dusky purple. In infancy, the ureterocele can prolapse during voiding, resulting in secondary bladder outlet obstruction, urinary retention, and a urological emergency [15]. Management of a prolapsed ureterocele involves manual reduction, often under anesthesia and urethral catheterization for several days. Treatment consists of needle decompression or incision with reduction followed by urethral catheterization. Later, definitive surgical therapy may be required.

About 90 % of ectopic ureteroceles drain the upper pole of a duplicated collecting system. A renal bladder US in the setting of a prolapsed ureterocele is performed to assess for collecting system duplication and upper pole hydronephrosis (Fig. 21.4). Retrograde pyelography can help delineate the relevant anatomy. Subsequent evaluation of the ureterocele also includes a VCUG to rule out concomitant vesicoureteral reflux and bladder abnormalities, as well as a nuclear medicine scan to determine split renal function.

Rhabdomyosarcoma is the fifth most common malignancy of childhood, accounting for 4–8 % of malignant disease in children under 15 years old [16]. Tumors arise from embryonal mesenchyme, a precursor of striated muscle. Histologic classification includes favorable histology, namely, embryonal rhabdomyosarcoma, with botryoid and spindle cell variants, as well as unfavorable histology, including alveolar, anaplastic, or undifferentiated [17]. About 29 % of cases of rhabdomyosarcoma are genitourinary in origin and most are embryonal [17]. Its botryoid variant has the best prognosis, with a 95 % 5-year survival [17]. Vaginal primary has the best prognosis of all female genital tract primary tumors, owing to favorable histology and early detection [18].

These tumors typically occur in children younger than 4 years old [17]. The classic, and most common, presentation of sarcoma botryoides is an interlabial, prolapsing mass arising from the vagina, bladder, or, rarely, cervix, resembling a “bunch of grapes.” Other presentations include an abdominal mass, bladder outlet obstruction, vaginal discharge, hematuria, bleeding, or passing of tumor fragments [17].

Workup involves a thorough history, physical exam, serum tests, and imaging. Initial imaging is performed with a US to confirm the tumor (Fig. 21.5). Cross-sectional imaging with CT or MRI is recommended to assess the tumor, lymph node involvement, and possible metastases. CT may be superior in assessing abdominal lymphadenopathy, although MRI is often recommended because it lacks ionizing radiation [19]. Limitations of MRI include the following: edema after radiotherapy can be misinterpreted as residual disease in 20 % of cases [20], bright urine on T2 imaging may obscure bladder wall tumors, and, on a delayed post-intravascular contrast scan, gadolinium can confuse interpretation when it layers in the bladder. Therefore, we perform multiphase post-contrast MRI in the evaluation of pelvic masses, which include an arterial, venous, and delayed phase [21]. Importantly, the same modality needs to be used for follow-up after therapy. Contrast cystograms and IVPs are rarely required today. Bone marrow biopsy and bone scintigraphy can assess distant spread. PET is not considered a standard staging modality for rhabdomyosarcoma [22].

Diagnosis requires adequate biopsy, preferably by endoscopy, which is less invasive than percutaneous biopsy and avoids needle tract seeding. If endoscopic biopsy is not possible, percutaneous core biopsy with a Tru-Cut needle or surgical biopsy can also be considered. Fine-needle biopsy is often inadequate. Treatment is multimodal, involving multi-agent chemotherapy, surgical excision, and possible adjuvant radiation. Therapy is aimed at preserving function, especially of the bladder, without affecting survival.

Disorders of sexual differentiation (DSD) require a multidisciplinary approach. A thorough and timely workup allows for appropriate diagnosis, management of any acute medical problems, parental counseling, and gender assignment. It includes the physical exam, imaging, karyotyping, biochemical and hormonal testing, as well as possible laparotomy or laparoscopy with tissue biopsy.

Gonads in individuals with DSD and a Y chromosome are at an elevated risk of developing gonadoblastoma and dysgerminoma. Management involves either a gonadectomy or, with appropriate counseling in children raised male, an orchidopexy. This allows for an early detection of possible malignant transformation (Fig. 21.11).