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Updated: May 22, 2026
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Spatial and Temporal Control of Murine Melanoma Initiation from Mutant Melanocyte Stem Cells
Published on: June 7, 2019
Metastatic melanoma and melanogenuria
Ohara Aivaz1, Erich M Gaertner, Scott A Norton
1Washington Hospital Center, Washington, DC, USA. oharaaivaz@gmail.com
Cutis
|April 26, 2012
Summary
A rare case of disseminated melanoma presented with black urine (melanuria). This finding, caused by oxidized melanin precursors, may help monitor melanoma prognosis and treatment response.
Area of Science:
- Oncology
- Dermatology
- Pathology
Background:
- Nodular melanoma is an aggressive form of skin cancer.
- Disseminated melanoma can present with various metastatic patterns.
- Melanuria, or black urine, is a rare clinical sign associated with melanoma.
Observation:
- A 70-year-old man presented with a nodular melanoma and metastatic cervical lymphadenopathy.
- One year post-palliative surgery, the patient developed widespread skin metastases and uniformly gray-brown skin.
- Urine samples turned black upon exposure to air, indicating melanuria.
Findings:
- Histopathology confirmed nodular melanoma with a Breslow thickness of 17 mm.
- The black urine was attributed to the oxidation of melanin precursors (melanogenuria).
- Widespread metastatic disease was evident through ulcerated masses on the trunk and extremities.
Implications:
- Melanuria serves as a rare but significant indicator of advanced, disseminated melanoma.
- Urinary melanin precursors may offer a future biomarker for melanoma prognosis and treatment monitoring.
- This case highlights the importance of recognizing unusual clinical signs in advanced cancer staging.
