SEER Inquiry System - View
Source 1: 2012 Heme & Lymph Manual & DB
Primary site--Heme & Lymphoid Neoplasms: What is the correct site code for this case? Diagnosis of multifocal Langerhans cell histiocytosis with involvement of bone, liver, spleen and retroperitoneum.
See the Hematopoietic DB Abstractor Notes for Langerhans cell histiocytosis: The dominent sites of involvement in the SOLITARY FORM are bone and adjacent soft tissue (skull, femur, vertebra, pelvic bones, and ribs). The MULTISYSTEM disease involves the skin, bone liver, spleen , and bone marrow.
This is a multisystem Langerhans cell histiocytosis (LCH). Because spleen and liver are not PRIMARY sites of involvement (they become involved because they filter the blood), the two sites that are left are bones and the retroperitoneum. Because bone is the most common site for LCH, you would default to bone, NOS C419, assuming there are multiple bones involved. If only one bone is involved, code to that bone.