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Diffuse cutaneous melanosis in malignant melanoma

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Diffuse cutaneous melanosis in malignant melanoma
Thomas de Aquino Paulo Filho MD, Pedro Bezerra da Trindade Neto MD, Juliana Costa Reis MD, Luther A Bartelt MD, Sidney Augusto Cruz da Costa MD
Dermatology Online Journal 12 (3): 9

Onofre Lopes Hospital, Dermatology Service, Rio Grande do Norte University, Natal, BRAZIL.

Clinical synopsis

Figure 1 Figure 2
Figure 1. Normal face before tumor
Figure 2. Primary lesion

Figure 3 Figure 4
Figure 3. Dark face after tumor developed
Figure 4. Green eyes (not affected)

Figure 5 Figure 6
Figure 5. Blue nails
Figure 6. Dark urine

Figure 7
Figure 7. histopathology

A 49-year-old white male Brazilian farmer with green eyes presented with 7 months of progressive mucosal and skin hyperpigmentation, darkened urine, hepatosplenomegaly, weight loss of 10.5 kg, and asthenia. Further history revealed that the patient had undergone partial excision of a left-sided postauricular hyperpigmented lesion 3 years previously, without histopathological review. Dermatologic exam showed diffuse hyperpigmentation, blue-tinged nails, darkened conjunctivae, ulcerated submental lesions, many subcutaneous nodules and a hyperpigmented left-sided postauricular ulcerated tumor. General exam also revealed axillary and inguinal lymphadenopathy. Histopathological review confirmed the diagnosis of metastatic melanoma. Additionally, there was melanin deposition between collagen fibers in areas of sun-damaged skin, but without clinical evidence of malignancy. The urine was dark, suggestive of melannuria, but confirming analysis was unavailable. The patient was referred to an oncologist. He received one course of chemotherapy, but subsequently developed brain metastases and died rapidly.


Diffuse cutaneous melanosis is extremely rare in comparison to the number of patients with metastatic melanoma. The pathogenesis is currently controversial. The differential diagnosis of diffuse hyperpigmentation should include hemochromatosis, argyria, porphyria cutanea tarda, and Addison disease.

© 2007 Dermatology Online Journal