Multifocal Multisystem Langerhans Cell Histiocytosis in an Adult Female Atypically Presenting With Multiple Abdominopelvic Abscesses

Introduction: Langerhans Cell Histiocytosis (LCH) is a condition of malignant clonal proliferation of myeloid bone marrow cells that more commonly affects children than adults. Furthermore, its presentation remains variable ranging from single organ to multisystem involvement including bone, skin, lymph, liver, spleen, lung, and central nervous system. We report an unusual case of multisystem LCH in an adult female presenting with multiple soft tissue abscesses. Case: We report a case of a 38-year-old female with a past medical history of polysubstance abuse, type 2 diabetes, polycystic ovarian syndrome, and isolated central diabetes insipidus who had multiple hospitalizations for recurrent soft tissue abscesses treated with incision and drainage and antibiotics. Imaging studies revealed multiple osteolytic lesions involving the bilateral iliac crests, acetabulum and femur, as well as an iliopsoas abscess. Given her prior history of isolated central diabetes insipidus, the possibility of LCH as the cause was entertained. Histological evaluation performed on an inguinal soft tissue sample stained positive for CD1a and S100, and a formal diagnosis of Langerhans Cell Histiocytosis (LCH) was made. The patient was treated with chemotherapy with good results. Conclusion: This report presents a rare and unusual case of adult onset multisystem LCH involving bone, skin, lymph, and central nervous system presenting with recurrent large abdominopelvic abscesses. These abscesses may represent a rare and unrecognized form of soft tissue involvement of LCH.