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- What are the causes of testicular enlargement with GIPP?
GIPP is independent of reactivation of HPG-axis; hence, it is not accompanied
with testicular enlargement. However, certain clinical disorders can have bilat-
eral symmetrical/asymmetrical testicular enlargement despite GIPP, and these
disorders include testotoxicosis, primary hypothyroidism, McCune–Albright
syndrome, and congenital adrenal hyperplasia with concurrent testicular adre-
nal rest tumor (TART) and hCG-secreting tumors like germinoma and hepato-
blastoma. On the contrary, Leydig cell tumor may have unilateral testicular
enlargement. All of these disorders, except primary hypothyroidism, are associ-
ated with pubarche and phallic enlargement.- A 7-year-old boy presented with appearance of pubic hair. On examination, his
testicular volume was 4 ml bilaterally, stretched penile length was 8 cm, and
pubic hair staging was P 3. Hormonal profile revealed LH <0.1 μIU/ml and
testosterone 33 nmol/L. What are the possibilities?
The presence of testicular enlargement with penile growth and pubarche in a
7-year-old boy suggests a clinical possibility of GDPP. However, the index
patient had disproportionate penile enlargement and pubic hair growth as
compared to testicular growth, which is a clue to the presence of GIPP. Hormonal
evaluation showed suppressed LH and elevated testosterone. In view of testicu-
lar enlargement and low diagnostic sensitivity (35 %) of basal LH in establishing
the diagnosis of GDPP, GnRH stimulation test was performed. Absence of
pubertal LH response to GnRH confirmed the diagnosis of GIPP. The disorders
associated with LH-independent testosterone secretion (GIPP) include congeni-
tal adrenal hyperplasia, hCG-secreting tumors, adrenal or Leydig cell tumors,
McCune–Albright syndrome, testotoxicosis, and exogenous testosterone ther-
apy. The index patient had symmetrical testicular enlargement in the presence of
GIPP, the differential diagnosis in the given scenario include CAH with testicu-
lar adrenal rest tumor, hCG-secreting tumors, McCune–Albright syndrome, and
testotoxicosis. Further, ACTH-stimulated 17-OHP was normal, and serum hCG
was 12,000 IU/L (N < 0.8), suggesting a diagnosis of hCG-secreting tumor. USG
and CT scan of the abdomen did not reveal any abnormality and MRI brain
demonstrated a mass lesion in the region of third ventricle and a possibility of
germ cell tumor was considered, and the patient was subjected to chemo- and
radiotherapy (Fig. 6.7). The correlation between pubic hair staging and testicular
volume in normal children is shown in the table given below.
Pubic hair stage Testicular size (ml) mean ± SE
P 1 1.9 ± 0.02
P 2 3.3 ± 0.06
P 3 5.3 ± 0.24
P 4 10.9 ± 0.34
P 5 15.6 ± 0.27
Adapted from Lall K, Singhi S, Gurnani M, Chowdhary B, Garg O. Normal testicular volume in
school children. Indian J Pediatr. 1980;47(5):389–93.
6 Precocious Puberty