Langherhans cell histiocytosis presenting as primary infertility in a young male

Langerhans cell histiocytosis (LCH) is a rare clonal neoplastic disorder of Langerhans cells, with an incidence rate of 5 per million individuals. In adults LCH usually affects bone followed by lung, skin, pituitary gland, liver, spleen, and orbits. LCH presenting with endocrinopathy is rare and commonly involves posterior pituitary with central diabetes insipidus (DI). Here, we present a rare case of LCH involving posterior pituitary but presenting as infertility in a 25-year-old married man. Later the thyroid gland was also found to be involved in the form of multiple nodules. Fine needle aspiration cytology (FNAC) from right lobe of thyroid showed sheets of Langerhans cells along with entrapped residual thyroid follicular cells which were further confirmed by immunocytochemistry as well as cell block preparation followed by immunohistochemistry. A final diagnosis of LCH involving pituitary and thyroid was made and patient was then started on treatment according to LCH treatment protocol LCH III-6 consisting of prednisolone and vinblastine (6 weeks with daily 40 mg/m2 oral prednisolone, and 6 mg/m2 i.v. vinblastine every 7 days). Patient is responding well to the therapy and is on follow up.