Metastatic patterns of skin cancer (non-melanoma)
Basal cell carcinoma
Basal cell carcinoma is a local disease and almost never spreads to lymph nodes or other organs. However, if left untreated it can cause considerable local problems including tissue destruction, infiltration of neighboring organs, and loss of function.
Squamous cell carcinoma
Squamous cell carcinoma can cause local problems and spread both lymphatically and hematogenously. The most common localizations for metastases are the lungs, liver, and bone.
Lymph nodes in the head/neck region which can be involved by metastasis from squamous cell carcinoma
Groups of lymph nodes usually drain specific skin areas, even if there is overlapping in border areas. For spreading which occurs after treatment of the primary tumor, it is important to know where the primary tumor was.
Lymph node areas which drain from the rest of the body
If one or more lymph nodes (marked in black) are involved outside the primary drainage area of the skin section (marked in gray), it is considered a distant metastasis M1, and not primary lymph node spreading.