Generalized melanosis of macro- and microphages in metastasizing melanoma

A patient suffering from a metastasizing malignant melanoma of the skin developed diffuse melanosis of the skin and melanuria a few weeks before death occurred. At autopsy, disseminated metastases of malignant melanoma were associated with marked melanosis of the organs and particularly of the mononuclear phagocytic system. In addition, neutrophilic granulocytes of the peripheral blood frequently contained melanin granules. The presence of melanin in blood monocytes and granulocytes may be useful for the diagnosis of (metastasizing) malignant melanoma.     

Trichochromuria in melanosis of melanoma

Two patients with metastasizing melanoma and diffuse melanosis have previously been reported to excrete large quantities of trichochromes in the urine. The present study describes 2 further melanoma patients with diffuse melanosis and trichochromuria. The hair of one of the patients which had been red in childhood and turned brown in adult age returned to red with the appearance of melanosis. Normal excretion of a methylated melanocytic metabolite, 6-hydroxy-5-methoxyindole-2-carboxylic acid, was observed in this patient, possibly indicating exhaustion of the methylating system. The other patients excreted large quantities of 6-hydroxy-5-methoxyindole-2-carboxylic acid. Both patients showed highly increased excretion of 5-S-cysteinyldopa. Both patients with melanosis exhibited fine electrone-dense granules in lysosomes of dermal histiocytes. The findings support the concept that trichochromes or similar pigments in dermal histiocytes are responsible for diffuse melanosis in melanoma patients.     

Diffuse melanosis in metastatic malignant melanoma

The skin of a patient with diffuse melanosis as a result of malignant melanoma was examined by light microscopy, immunohistochemistry, and electron microscopy. Our findings indicate that the slate-blue discoloration in this patient was due to pigment deposition in dermal macrophages and endothelial cells. Multiple attempts to identify disseminated metastatic melanoma cells were unsuccessful.     

Fatal leptomeningeal melanoma in neurocutaneous melanosis

We report an unusual occurrence of a primary dural-based malignant melanoma in a 13-year-old boy with neurocutaneous melanosis. The lesion presented with rapid-onset symptoms characterized by raised intracranial pressure and seizures, had an aggressive clinical course, and proved to be fatal despite two surgeries and adjuvant therapy. There should be a high index of suspicion for the occurrence of such a malignant leptomeningeal tumor in patients with congenital melanocytic nevi presenting with neurological symptoms of recent onset.     

Diffuse melanosis and trichochromuria in malignant melanoma.

A previous finding of pronounced excretion of trichochromes in a patient with metastasizing melanoma and diffuse melanosis prompted this study on trichochromes in another patient with these two features. The patient now reported also excreted large amounts of trichochromes. Iit is suggested that diffuse melanosis in metastatic melanoma patients is due to deposition of trichochromes in the tissue.     

Pathogenesis of diffuse melanosis secondary to malignant melanoma

The heavily pigmented but otherwise normal appearing skin of a patient with diffuse melanosis secondary to metastatic malignant melanoma was examined by electron microscopy and electron microscopic cytochemistry. The findings indicate that the slate-blue colour of this melanosis is due, for the most part, to melanosomes derived from melanoma cells that have spread to and throughout the skin of the patient. The dissemination of individual, discrete tumour cells within the patient's dermis represents a unique form of single cell metastasization.     

Generalized melanosis with malignant melanoma metastasizing to skin—a pathological study with S-100 protein and HMB-45

A patient with primary malignant melanoma localized to the right gluteal region is described. Four years later and alter intercurrent influenza, disseminated metastases of malignant melanoma to the skin occurred. After a further 6 months melanodermia developed and lasted until the death of the patient (6 months later). Autopsy revealed melanosis of the visceral organs. Histology taken from internal organs using S-100 protein and HMB-45 melanoma methods confirmed metastases of malignant melanoma to the skin, oral cavity, palatal tonsils, nasal and nasopharyngeal mucosae, lungs, myocardium and brain. The authors discuss the mechanism of melanosis—a rare sign in patients with metastasizing malignant melanoma.     

Alopecia neoplastica caused by desmoplastic melanoma

A 50-year-old man presented with a 6-month history of localized alopecia on the left frontal area of the scalp. Biopsy revealed desmoplastic melanoma with associated neurotropism. Wide excision was performed and showed desmoplastic melanoma extending to excision margins. Hair follicles were focally reduced in number and were infiltrated by melanoma cells. He has subsequently required multiple wide excisions, exenteration of the left eye and radiotherapy. He has had multiple recurrences and has developed involvement of the first division of the trigeminal nerve intracranially. To the authors' knowledge, this is the first reported case of desmoplastic melanoma presenting as alopecia.     

Extensive tumoral melanosis associated with ipilimumab‐treated melanoma

Tumoral melanosis describes a pigmented lesion clinically similar to melanoma but on histology reveals dense aggregates of melanin‐laden, benign macrophages without malignant cells. In the few reported cases so far, tumoral melanosis has arisen in the skin or lymph node of a patient with a regressed melanoma or an epithelioid tumour. As a marker of regressed primary melanoma, its discovery may prompt investigation and surveillance for undiagnosed local or metastatic disease. Here, we present a unique case of extensive tumoral melanosis arising during ipilimumab treatment of in‐transit metastases from a previously excised melanoma.     

Diffuse melanosis with generalized and ocular metastasis in malignant melanoma

In a 48-year-old female patient 9 months after excision of a nodular melanoma on the back, multiple cutaneous, subcutaneous and lymph node metastases developed. Thereafter diffuse melanosis developed together with ocular metastatic involvement during immunochemotherapy with BCG and dacarbazine (DTIC). Most of the cutaneous metastases disappeared spontaneously with halo formation, while new nodes formed. The patient survived with disseminated melanoma more than 2 1/2 years without cytostatic therapy, before she died from intestinal metastases.     

Vulvar melanoma: diffuse melanosis and metastasis to the placenta

Mucocutaneous melanoma, including vulvar melanoma, is rare and has a worse prognosis and higher recurrence rate than traditional cutaneous melanoma. Diffuse cutaneous melanosis is another rare clinical presentation of metastatic melanoma. It is essential for dermatologists to be alerted to rare presentations of melanoma, to facilitate early detection. We present the first case to our knowledge of metastatic vulvar melanoma with diffuse cutaneous melanosis in a pregnant young woman. Despite the occurrence of placental metastasis, a healthy, unaffected baby was born. This case exemplifies the aggressiveness of vulvar melanoma. The genitalia should be included in routine total body skin examinations. Pregnant women with generalized melanosis may be at increased risk for placental metastasis of melanoma. Pregnancy does not alter the incidence or prognosis of melanoma; however, patients with a poor prognosis or high recurrence risk should be informed of potential pregnancy complications associated with melanoma recurrence or metastasis.