Introduction/Background Endosalpingiosis is the presence of tubal epithelium outside the tube. It is linked to pelvic pain, mass effects, infertility and urinary symptoms. Sometimes concurrent malignancy can exist, low-grade serous carcinoma being the most common. We present a rare case of inguinal node papillary serous carcinoma on the background of endosalpingiosis.

Methodology This is a 59-year old woman whose tru-cut biopsy of an enlarged inguinal node showed metastatic low-grade papillary serous carcinoma of possible ovarian primary. Staging CT and whole body PET scan confirmed no evidence of metastatic disease.

Results A laparoscopic bilateral salpingo-oophorectomy and hysteroscopy were performed. The histology showed no evidence of atypia or malignancy. Central MDT review recommended bilateral groin lymphadenectomy. Final histology confirmed 1/6 right node having borderline serous carcinoma and 1/9 left node having invasive low-grade serous carcinoma both arising in lymph-node endosalpingiosis. The patient remains asymptomatic and a CT Thorax-Abdomen-Pelvis performed 6 months after the diagnosis showed no evidence of recurrent or metastatic disease.

Conclusion There are several theories regarding endosalpingiosis like implantation of tubal epithelium after procedures involving the fallopian tube, direct spread of tubal epithelium cells or metaplasia of the mesothelial cells.

Endosalpingiotic nodal involvement with low-grade serous ovarian carcinoma has been described. However it is the second case report of inguinal node low-grade serous carcinoma arising from endosalpingiosis with no obvious adnexal involvement and the first to histologically exclude adnexal primary.

Disclosure Nothing to disclose.