AIS is the most common type of male pseudohermafroditism characterized by absence of androgen receptor (AR) activity due to a mutation at Xq11–q12 localization on the androgen receptor gene (
3-
5). It is known as an X-linked recessive disease, but up to 30% of mutations may be presented as sporadic de novo mutations (
6). The incidence of this condition is 1 in 99,000 to 1 in 20,000 female births (
7-
9). These patients may be seen with a spectrum of phenotypic disorders that varies from pure female complete androgen insensitivity syndrome (CAIS), ambiguous genitalia partial androgen insensitivity (PAIS) and to phenotypically infertile male minimal androgen insensitivity form (MAIS) (
2).
The complete form is 10 times more common than the incomplete form and the initial presentation is primary amenorrhea in adolescents with female phenotype, lack of pubic hair, or inguinal hernia containing testis and characterized by a 46 XY genotype and normal male androgen and gonadotropin value. Pelvic ultrasonography usually shows absence of mullerian derivates and vaginal examination reveals a blind-ending vagina without a cervix. Notably, on physical examination, all of these characteristics were present in our patient (
2). In children or infants with a female phenotype, androgen insensitivity syndrome may present as inguinal hernia or mass and ambiguous genitalia. About 50% of patients with complete (severe) AIS have an inguinal hernia. Conversely, 1-2% of apparently female infants with inguinal hernia are diagnosed to have a 46 XY karyotype and complete AIS. It may be found during workup for lower abdominal pain (
10), abdominal mass (
11), painful intercourse, or diagnosed incidentally on imaging investigations (
12). The testes may be found in the abdomen, inguinal canal, or labia. Abnormalities of testicular development and risk of gonad malignancy increase after puberty.
Testis tumor developing risk is thought to be 3.6% by 25 years and 33% by 50 years (
11,
13). In a case series of 43 patients with AIS by Rutgers and Scully, 63% hamartomas, 23% sertoli cell adenomas and 9% malignant tumors including two seminomas, one intratubular germ cell neoplasm with early stromal invasion and a malignant sex cord tumor were reported (
13). We reviewed the previous articles on gonadal tumors in CAIS patients (
Table 1). Most cases are unilateral sertoli adenoma or tumor. There are only two reported cases of bilateral gonadal tumors (
10,
14). Also, there are only two cases of sertoli-leydig cell tumor which both were unilateral (
15,
16).
In AIS pateints, prophylactic gonadectomy is advised in the postpubertal period due to avoid potential malignant transformation of the gonads (
2,
28). Gonadectomy is recommended during the postpubertal period to help the development of feminization during puberty when the malignant changes in germ cells are relatively late and rare (
13).
Sertoli-leydig cell tumor is a rare sex cord stromal neoplasm that account for less than 1% of ovarian tumors, occurring often in young adults (
29,
30). It is also seldom developed among the patients with AIS and there is only two unilateral cases reported in the literature (
15,
16). According to the amount of tubular differentiation of the sertoli cells and quantity of the primitive gonadal stroma, sertoli-leydig cell tumor is divided into well, intermediate and poorly differentiated types. Our patient had a well-differentiated form of SLCT, which is the most infrequently type seen with the good prognosis. To our knowledge, this is the first documented case report of bilateral benign sertoli-leydig cell tumor (SLCT) in androgen insensitivity syndrome.