Diagnostic Conundrum of a Sertoli Cell Tumor in a 2-Year-Old Girl with Peripheral Precocious Puberty and a Café-Au-Lait Macule: A Case Report.

INTRODUCTION: Ovarian Sertoli cell tumors represent a subset of sex cord-stromal tumors and are exceedingly rare in prepubertal children. Here we report a girl with vaginal bleeding due to a Sertoli cell tumor who was originally thought to have McCune-Albright syndrome (MAS).

CASE PRESENTATION: A previously healthy girl presented at age two years six months with breast development and vaginal bleeding. On exam, she had Tanner 4 breasts, Tanner 1 pubic hair, estrogenized vaginal mucosa, and a café-au-lait macule. Laboratory studies revealed an elevated estradiol with suppressed gonadotropins and negative tumor markers. Her bone age was advanced by more than three years. Pelvic ultrasound (US) revealed an enlarged uterus and a slightly larger left compared to right ovary. She was started on tamoxifen for presumed MAS. A repeat pelvic US one month later showed a heterogenous mass in the left ovary which was subsequently resected. Pathology revealed a Sertoli cell tumor, lipid-rich variant. Germline sequencing revealed a pathogenic STK11 variant, diagnostic for Peutz-Jeghers syndrome (PJS).

CONCLUSION: The findings in our patient were strikingly similar to those encountered in MAS. To our knowledge, our patient is the youngest ever reported to present with precocious puberty due to a Sertoli cell tumor in the setting of PJS.