Incidental Langerhans cell histiocytosis associated with metastatic neuroendocrine tumor in the adult liver.

This is an unusual adult case of a metastatic well-differentiated neuroendocrine tumor with incidentally discovered subtle involvement of Langerhans cell histiocytosis (LCH), a clonal proliferation of Langerhans cells. It is important to recognize that LCH can often co-exist with other malignancies (solid > hematologic).