ESPE Abstracts

Case presentation: We report on an Irish boy who presented aged 8 years old with an 18 month history of gradual right-sided gynaecomastia, which was surgically excised with good cosmetic outcome. He subsequently re-presented with left-sided breast tenderness and budding and was then referred to endocrinology. On review, his height was greater than the 99th centile, weight was on the 75th centile and bone age was advanced by 2 years and 9 months. Tanner staging showed stage 2 glandular breast tissue on the left, with progressive virilisation of the phallus (G2-3) over a 6 month period. He had developed body odour and downy scrotal hair. His testicular volumes were however in the prepubertal range (3mls). Testicular ultrasound demonstrated multiple small punctate echogenic foci throughout both testes. He was also noted to have lip and facial freckling. Investigations showed levels of oestradiol in the upper normal range and pre-pubertal LH/FSH (<0.1IU/0.1IU/l). A genetic panel confirmed a de novo STK11 heterozygous missense pathogenic variant, likely pathogenic for Peutz-Jeghers Syndrome (PJS), while PRKAR1a analysis was normal making Carney complex unlikely. A left sided mastectomy versus commencing an aromatase inhibitor was discussed resulting in treatment with anastrozole (1 mg once daily) starting at 9.5 years old. His growth velocity and bone age stabilised and left-sided breast budding rapidly resolved leaving only some skin laxity. He has since been followed to the age of 13 years old. He entered true puberty at 10 years 10 months old and has to date a preserved height centile. α-inhibin, which may be raised in this condition, was normal but tested only after commencement of anastrozole. He commenced on a PJS malignancy screening programme which has shown some intestinal polyps but otherwise has remained reassuring. His repeated testicular ultrasounds have remained stable in appearance (most recently 12 years 10 months).

Discussion and Conclusion: PJS is a rare autosomal dominant condition characterised by small melanocytic mucocutaneous pigmentations and intestinal polyposis and an increased lifetime malignancy risk. Sertoli cell tumours of the testis have been reported in young boys with PJS and are known to secrete oestrogen which can lead to pseudopuberty. Due to their specificity in PJS and low malignancy potential, biopsy is no longer indicated to confirm the diagnosis, but they must be followed with regular ultrasound. In this case, to date, treatment with an aromatase inhibitor has negated the need for further surgery and thus far preserved his height potential.