Tumors Involving Skin, Soft Tissue and Skeletal Muscle: Benign, Primary Malignant or Metastatic?

Background: Metastatic cancer with invasion of skin, soft tissue and skeletal muscle is not common. Examplespresenting as soft tissue masses could sometimes lead to misdiagnosis with delayed or inappropriate management.The purpose of current study was to investigate clinical characteristics in the involvement of metastatic cancer.Materials and
Methods: A total of 1,097 patients complaining of skin or soft tissue masses and/or lesions wereretrospectively reviewed from January 2012 to June 2013. Tumors involving skin, soft tissue and skeletal muscleof head and neck, chest wall, abdominal wall, pelvic region, back, upper and lower extremities were includedin the study.
Results: Fifty-seven (5.2%) patients were recognized as having malignancies on histopathologicalexamination. The most common involvement of malignancy was basal cell carcinoma, followed by cutaneoussquamous cell carcinoma, sarcoma and melanoma. The most common anatomical location in skin and soft tissuemalignancies was head and neck (52.6% of the malignancies). Four (0.36%) of the malignant group were identifiedas metastatic cancer with the primary cancer source from lung, liver and tonsil and the most common site wasupper extremities. One of them unexpectedly expired during the operation of metastatic tumor excision at thescalp.
Conclusions: Discrimination between benign and malignant soft tissue tumors is crucial. Performanceof imaging study could assist in the differential diagnosis and the pre-operative risk evaluation of metastatictumors involving skin, soft tissue and skeletal muscle.