323- How to establish the diagnosis of OT - DSD?
The characteristic karyotype 46,XX/46,XY is present only in 20 % patients
with OT-DSD, whereas 46,XX karyotype is present in 70 % and 46,XY karyo-
type in 10 %. Hence, the diagnosis of OT-DSD should be established histo-
pathologically by demonstration of ovarian tissue (containing primordial or
maturing follicles) and testicular tissue (containing seminiferous tubules with
spermatogonia) either in the same gonad or in different gonads. Ovotestes are
the most frequent gonad present in patients with OT-DSD, followed by ovary
and testis. 50 % of patients with OT-DSD have unilateral ovotestes with either
a testis or ovary on the other side, 30 % of patients have bilateral ovotestes,
while the rest (20 %) have ovary on one side and testis on the other side. Testis
is commonly located in scrotum, ovary in the abdomen, and ovotestis can be
present anywhere along the route of testicular descent from abdomen to labio-
scrotal fold.- What are the DSDs associated with ovotestis?
The term ovotestis denotes the presence of ovarian follicles and seminiferous
tubules within the same gonad. The classical disorder associated with ovotestis
is 46,XX or 46,XX/46,XY or 46,XY ovotesticular DSD. Other rare disorders
associated with ovotestis include SRY gene translocation and inactivating
mutations of RSPO1, SOX9, and WNT4.- A 20 - year - old individual , who was reared as male , was referred for diagnostic
evaluation for DSD. He had history of surgery for gynecomastia at the age of
15 years and multiple surgeries for hypospadias. The clinical profi le of the
patient is depicted below. What is the differential diagnosis in the index case?
The index patient had immature facies, poor facial hair, and feminine voice
suggestive of hypogonadism. Genital examination revealed Tanner pubic
hair stage P 4 , bilateral scrotal testes (size 15 ml bilateral), microphallus
(stretched penile length 7 cm), penile hypospadias (despite multiple correc-
tive surgeries), and redundant skin folds (after corrective surgery). The dif-
ferential diagnosis in this individual with genital ambiguity, bilateral
palpable gonads, and gynecomastia includes partial androgen insensitivity
and androgen biosynthetic defects. The two disorders can be differentiated
based on serum testosterone and LH levels. High normal to elevated serum
testosterone with normal to raised LH suggest a diagnosis of partial andro-
gen insensitivity, whereas low serum testosterone and elevated LH suggest
androgen biosynthetic defects. The index patient had karyotype 46,XY, had
serum testosterone 16 nmol/L and LH 12 μIU/ml, and was diagnosed to have
PAIS (Fig. 9.17 ).9 Disorders of Sex Development