METASTATIC MELANOMA. A CLINICOPATHOLOGICAL STUDY

Metastatic Melanoma to the Urinary Bladder: A Rare Cause of Visible Haematuria

Bladder metastasis from cutaneous melanoma is a rare pathology. A 79-year-old woman presented to the haematuria clinic on account of painless visible haematuria. Ten years prior to this index presentation, she was diagnosed with melanoma on her right thigh following a total excision of the skin lesion. Cystoscopy showed a pigmented bladder tumour, and the histology report following a transurethral resection was consistent with metastatic melanoma, and further imaging revealed metastasis to the lungs, adrenals, and lymph nodes.

A Case Report of Primary Malignant Melanoma of the Gallbladder with Multiple Metastases

Primary malignant melanoma of the gallbladder is an extremely rare tumor with approximately 39 cases described in the literature so far. However, since the first case was reported in 1907, it remains controversial whether gallbladder involvement in malignant melanoma is primary or metastatic. Here, we report a case of primary malignant melanoma of the gallbladder. A 52-year-old male presented to the emergency department with right upper quadrant abdominal pain and was found to have tumefactive sludge filling the majority of the gallbladder with possible gallbladder wall thickening on ultrasonography. A laparoscopic cholecystectomy was performed for presumed acute cholecystitis. Histopathologic examination of the gallbladder revealed malignant melanoma arising from the mucosa of the gallbladder. Further clinical investigation excluded other primary sites, supporting a diagnosis of primary malignant melanoma of the gallbladder.

Human KIT+ myeloid cells facilitate visceral metastasis by melanoma

Metastasis of melanoma significantly worsens prognosis; thus, therapeutic interventions that prevent metastasis could improve patient outcomes. Here, we show using humanized mice that colonization of distant visceral organs with melanoma is dependent upon a human CD33+CD11b+CD117+ progenitor cell subset comprising <4% of the human CD45+ leukocytes. Metastatic tumor-infiltrating CD33+ cells from patients and humanized (h)NSG-SGM3 mice showed converging transcriptional profiles. Single-cell RNA-seq analysis identified a gene signature of a KIT/CD117-expressing CD33+ subset that correlated with decreased overall survival in a TCGA melanoma cohort. Thus, human CD33+CD11b+CD117+ myeloid cells represent a novel candidate biomarker as well as a therapeutic target for metastatic melanoma.

Primary melanoma of the gallbladder: Does it exist? Report of a case and review of the literature

With the occasion of a case of malignant melanoma of the gallbladder, which appeared to be primary, we have reviewed the literature and the result of this research was that primary melanoma of the gallbladder remains a questionable medical entity. Only few cases of both primary and metastatic gallbladder melanoma have been reported so far, and the only agreement is that surgery is the mainstay treatment. The role of adjuvant chemotherapy, hormonotherapy or immunotherapy for both primary and metastatic disease remains undefined.