Endocrine Abstracts

Background: Peutz Jegher’s syndrome is a rare condition with substantial cancer risk. Testicular cancer risk is 9%, the commonest being pre-pubertal large cell Sertoli cell tumour (LCST) which usually presents with bilateral gynecomastia. Here we present a case of Peutz Jegher’s syndrome with LCST who presented with unilateral gynecomastia.

Case: A 5-year-old boy was referred to our endocrine service with unilateral gynecomastia. He had right sided gynecomastia (stage 4 with a disc of 4.5 cm) with bilateral testicular enlargement (4–5 ml) and no evidence of pubic hair or penile growth. He also had dark pigmentation of the buccal mucosa of the lips and cheeks.

His testosterone was 0.4 nmol/l, with oestrogen of 44 pmol/l. LH-releasing hormone (LHRH) stimulation test showed a pre-pubertal response with peak LH of 1.9 I.U/l and FSH of 0.3 I.U/l. Ultrasound scan (USS) of the breast was normal and Doppler USS of the testes showed bilateral enlarged testicles with speckled appearance suggestive of Sertoli cell tumour. The rest of his investigations were normal except high levels of Inhibin B (295.5 ng/l). The clinical picture was suggestive of Peutz Jegher’s syndrome. Endoscopy revealed several benign gastric and duodenal polyps. His testicular biopsy confirmed intratubular LCST without evidence of malignancy. Genetic tests revealed mutations in the STH11 gene confirming the diagnosis.

In view of the advanced bone age and progression of gynecomastia he was started on letrazole with good effect. He continues to have regular reviews with testicular USS to monitor the Sertoli cell tumour and endoscopy for the polyps.

Conclusion: Peutz Jegher’s syndrome must be considered in all cases of pre-pubertal gynecomastia which can rarely be unilateral as in our case. Aromatase inhibitors like letrazole are efficient in controlling clinical symptoms. In view of 27% reported risk of malignant transformation of the LCST, regular surveillance has been recommended.