#1: Primary site
#2: Unknown & ill-defined sit
Source 1: 2018 SEER Manual
Primary site/Unknown and ill-defined site--Melanoma: What is the primary site for a case of metastatic melanoma with an unknown primary site? See Discussion.
A patient had posterior cervical lymphadenopathy status post biopsy and subsequent lymph node dissection showed metastatic melanoma in 2018. Workup showed no skin lesions or primary site. Final diagnosis is melanoma of unknown primary (unknown if cutaneous or non-cutaneous). Should C760 be used as the primary site for this case since the histology codes of 8700-8790 are included in the Cervical Lymph Nodes and Unknown Primary Tumors of the Head and Neck schema in SEER*RSA?
Code primary site C449. C449 is the default primary site code for melanoma of unknown primary site. C760 should not be assigned for this case. Updates will be made to SEER*RSA to remove the melanoma histology codes from the Cervical Lymph Nodes and Unknown Primary Tumors of the Head and Neck schema.