A metastatic malign melanoma case with diffuse cutaneous melanosis

Diffuse melanosis cutis secondary to metastatic malignant melanoma: case report

“…It is often associated with liver, lung and lymph nodes metastases. DCM also can be seen in Addison disease, porphyria cutanea tarda and hemochromatosis [3].…”

“…Bohm et al suggested that cutaneous diffuse melanosis is linked to an excessive production of melanocytic growth factors (MSH (melanocyte stimulating hormone), Hepatocyte growth factor (HGF), Endothelin-1 (ET-1)). Excessive production of MSH (from tumor), HGF and ET-1 (from distinct site of metastasis) induce normal and malignant melanocytes resulting in enhanced proliferation, melanogenesis and melanin releasing [3].…”

“…This may occur as a result of rapid turnover of neoplastic deposits, ischemia, immunological responses, or oncologic therapies [1]. Circulating precursors would have the capacity to traverse the glomerulus and be excreted in the urine, causing melanuria [1][2][3][4][5][6].…”

“…The most often described histological finding, was the presence of pigmented granules but not of malignant cells [5]. In most of the cases, biopsy specimens revealed that the hyperpigmentation resulted from a marked deposition of pigment in the dermis,Another finding was giant melanosomes in melanocytes, keratinocytes and melanophages [3,4]. Micrometastases or single metastatic melanoma cells, as rarely have been described.…”

“…The discoloration represents the abnormal presence of pigment within the dermis causing scattering of light [1], and is usually more intensive on sun-exposed areas, including head and upper torso [2]. Usually, dark urine associated with melanüri, darkening of the serum and peritoneal fluid can be also seen [3].…”