Plasmacytoid melanoma of the urinary bladder and lymph nodes with immunohistochemical expression of plasma cell markers revealing primary esophageal melanoma

Complete remission in metastatic primary malignant melanoma of the esophagus with nivolumab: a case report

Background

Primary malignant melanoma of the esophagus is a rare form of mucosal melanoma with a poor prognosis. While immune checkpoint inhibitors have recently extended overall survival in metastatic melanoma, data on their effects on primary malignant melanoma of the esophagus are limited because of its rarity. Here, we report the first case of long-term complete remission of metastatic primary malignant melanoma of the esophagus after nivolumab monotherapy.

Case presentation

A 79-year-old Asian man with a history of prostate cancer, gallbladder cancer, deep vein thrombosis, hypertension, and diabetes mellitus presented with gross hematuria. Cystoscopy revealed a solitary tumor on the right posterior wall of the bladder, and transurethral resection of bladder tumor was performed. Pathology was consistent with metastatic melanoma. A pigmented submucosal tumor-like growth in the esophagus was discovered on esophagogastroduodenoscopy. Computed tomography showed widespread metastases. The patient was diagnosed as having primary malignant melanoma of the esophagus with metastases to the stomach, subcutaneous tissue, lung, bladder, pleura, and peritoneum. Complete remission was achieved after seven cycles of triweekly nivolumab monotherapy. While nivolumab was discontinued because of kidney injury, the patient has remained tumor-free for over 4 years without further treatment.

Conclusion

Immune checkpoint inhibitors may have astonishing curative effects in selected populations. More research is warranted to identify factors that increase the likelihood of achieving complete remission in primary malignant melanoma of the esophagus as well as in other melanomas.

CD138 Expression Is Observed in the Urothelial Epithelium and in Various Urothelial Carcinomas, and Cannot Be Evidence for Plasmacytoid Urothelial Carcinoma

CD138 (syndecan-1) immunoexpression has been reported to be specific for the plasmacytoid variant of urothelial carcinomas (UCs). The aim of this study was to examine the utility of CD138 immunohistochemistry for diagnosing the plasmacytoid variant of UCs. The extent and intensity of CD138 immunostaining were evaluated in 22 infiltrating UCs, 2 other infiltrating carcinomas, 15 noninvasive urothelial lesions, 3 other benign lesions, and perilesional normal tissues. CD138 immunostaining of the normal urothelial epithelium was universally diffuse and strong. In addition, all 42 cases of urinary tract lesions exhibited positive CD138 immunostaining; however, 1 of 3 plasmacytoid variants exhibited focal CD138 expression. The frequency of CD138 positivity in plasmacytoid variants may be relatively low, compared with that observed in the conventional types and other variants; thus, it is not appropriate to assume that CD138 expression in UCs is specific for plasmacytoid variants.

Metastasis of Malignant Melanoma to Urinary Bladder: A Case Report and Review of the Literature

Aims. Metastatic malignant melanoma of the urinary bladder is a rare clinical entity, with only twenty-three published cases to date. We present a case of this rare entity, a thorough review of the literature, and differential diagnosis of melanoma in the bladder. Methods and Results. A 55-year-old woman with a history of malignant melanoma of the right thigh, excised eight years ago, presented with back pain, fatigue, and hematuria. She underwent computed tomography (CT) scan and was found to have metastases within the liver, spleen, lungs, and urinary bladder. She underwent cystoscopy and transurethral resection of three polypoid lesions. Histologic and immunohistochemical examination revealed metastatic malignant melanoma involving bladder mucosa. Conclusions. This case illustrates the importance of including malignant melanoma in the differential diagnosis of high grade neoplasms of bladder, especially in cases where the relevant clinical history is not available.

Amelanotic Melanoma Presenting with Plasmacytoid Morphology and BRAF V600 Mutation

Plasmacytoid melanoma is an unusual variant of malignant melanoma. The plasmacytoid morphology can be found in a variety of other malignancies including carcinomas, plasma cell neoplasms, lymphoproliferative disorders, and sarcomas. The authors report a rare case of plasmacytoid amelanotic malignant melanoma in a 78-year-old man presenting with an enlarging palpable, erythematous mass on his left posterior shoulder. A fine needle aspirate showed atypical findings with single amelanotic cells with high nuclear to cytoplasmic ratio, mono- and multi-nucleation with prominent nucleoli and intranuclear inclusions. Review of the excision and immunohistochemical analysis revealed the malignant plasmacytoid cells stained with vimentin, S-100, HMB-45, and other staining patterns consistent with melanoma. Initial evaluation was negative for other sites of disease. However, 4 months later, the patient was noted to have metastatic disease to his lungs and liver. Given that the tumor was noted to be BRAF V600R mutated, the patient was started on single agent dabrafenib. The plasmacytoid morphology can be found in a variety of malignancies. Melanoma should be considered in the differential diagnosis of any malignancy presenting with plasmacytoid features.

Melanoma of the urinary bladder: a review of the literature

Background. Melanomas of the urinary bladder and urethra are rare. Aims. To review the literature on the disease. Methods. Various Internet databases were used to identify reported cases of the disease. Results. Less than 30 cases of primary melanoma of the urinary bladder and urethra have been reported in the literature and they have been associated with melanosis and commonly with metastases. The lesions may be primary or metastatic with no gender preference. The diagnostic features include pigmented raised lesions which histologically exhibit spindled or epitheliod cells, necrosis, mitotic figures, and atypical melanocytes. Immunohistochemically they stain positively with S100; HMB45; and other melanocyte markers, but negatively with Keratin and Vimentin. The treatment involves excision and possibly IL-2. The prognostic factors include size and depth of invasion as well as metastatic lesions. Conclusions. Less than 30 cases (about 24 cases) of the disease have been reported. There are also reports of metastatic melanomas of the urinary bladder emanating from primary melanomas originating elsewhere. Diagnosis of the primary disease is based upon the histological appearance of the lesion, positive staining with S100 and HMB45, and evidence of absence of melanoma elsewhere. Primary melanoma of the bladder is usually a fatal lesion.