Skin Metastasis Lung, Colon, Melanoma, Renal
Historically, lung carcinoma is more common in men than women. There is a localized cluster of cutaneous non-specific nodules, most often on the anterior chest or abdomen. The diagnosis of lung cancer usually precedes the diagnosis of metastasis to the skin.
COLON AND RECTAL
Colon and rectal carcinoma is the second most common source of skin metastases in both genders. It usually presents late in the disease course. The abdomen and perineum are the most common sites. Less commonly, it may present as inflammatory metastatic carcinoma of the inguinal folds or as a chronic cutaneous fistula.
Melanoma is the third most common cause of metastasis to the skin. Melanoma typically invades the liver, lungs and brain but may also show up at distant cutaneous sites. Skin is the most common primary site of melanoma, followed by ocular and mucosal sites. There are cases of systemic or metastatic melanoma without a primary cutaneous melanoma. Melanoma that is metastatic to the skin typically appears as small 2-5 mm blue papules resembling blue berries. Hundreds of lesions may be present in advanced cases.
RENAL CELL CARCINOMA
Renal cell carcinoma comprises 7.0 % of all cutaneous metastases. It is notorious for presenting as a scalp nodule and most commonly presents on the head and neck region. A well-circumscribed, bluish nodule with prominent vascularity is a typical presentation.