Endocrine Abstracts

Introduction: Carney complex is a rare autosomal dominant genetic disorder which develops secondary to mutation in the PRKAR1A gene located in the 17q22-24 region. It is commonly characterised by the association between spotty skin pigmentation, cardiac myxoma and secretory endocrine tumors.

Case presentation: A 15.8-year-old boy known with PRKAR1A mutation diagnosed based on his personal history – cutaneous papiloma of the neck resected at the age of 6 years, bilateral testicular microlitiasis, right testicular teratoma resected at the age of 9 years, embolic stroke secondary to left atrial myxoma resected at the age of 10 years was adressed for tall stature. His family history is negative. Clinical examination reveals a height of +2.03 S.D. (+1.54 DS compared to his familial target height), a height growth velocity of 6 cm per year (+3.86 S.D.), BMI 19 kg/sm; no other specific findings are met. Thyroid function and neck ultrasound are normal. Prolactin, hypophiseal-gonadal axis and androgens are within the normal range. Testicular ultrasound reveals the presence of persistent bilateral microlitiasis, but tumor markers (BhCG and alfa-fetoprotein) are negative. IGF1 (468.5 ng/ml, +1.65 SDS), IGFBP3 (5401 ng/ml) have normal values, with a supressed growth hormone of 1.28 ng/ml after oral glucose dynamic testing. Bone age is comparable to the chronological age (16.5 years old). Serum ACTH (1 pg/ml) and 0800 h cortisol (10.78 μg/dl) levels and free urinary cortisol (240.87 μg/24 h) raise the susspicion of ACTH-independent hypercorticism. Liddle test shows paradoxal stimulation of both serum and free urinary cortisol after dexamethasone intake (baseline, day 2 and 6 serum cortisol of 4.46, 9 and 18.43 μg/dl, respectively; baseline, day 3 and 6 free urinary cortisol of 39.26, 81.85 and 903.15 μg/dl, respectively), thus confirming the diagnosis of adrenal hypercorticism. Abdominal MRI shows no pathological changes of the adrenal glands. The most probable diagnosis in this case is primary pigmented adrenal hyperplasia which often accompanies PRKAR1A mutation.

Discussion: The therapeutic approach is bilateral adrenalectomy, but given the absence of clinical glucocorticoid changes, patient’s family decision is to follow-up. He remains in observation for his height, but for the moment growth hormone excess can be excluded. This case particularities consists in the large range of clinical features of the Carney complex at an early age; still, one of the important feature of the syndrome –hypercorticism– was present in a subtle, subclinical manner and it was identified in a proactive evaluation.