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

Borderline phyllodes tumor with an incidental invasive tubular carcinoma and lobular carcinoma in situ component: a case report.

Phyllodes tumors are an infrequent breast tumor presentation. A phyllodes tumor with a synchronous invasive ductal carcinoma is rarely described and has never been reported with lobular carcinoma in situ component. A 53-year-old female presented with a nine-year history of twice core biopsy proven fibroadenoma. After an increase in the tumor\u27s growth velocity it was decided upon to undergo an excisional biopsy. Microscopic examination of the well-circumscribed pale-tan mass found focal areas of leaf like architecture with variable number of mitoses present, representing a phyllodes tumor of borderline malignant potential. Incidentally, at one edge of the mass was found a tubular carcinoma and lobular carcinoma in situ components. Thorough, routine follow-up of patients with biopsy proven benign breast masses is important to finding a masked malignant component

Comparing Current and Next-Generation Humanized Mouse Models for Advancing HIV and HIV/<i>Mtb</i> Co-Infection Studies

In people living with HIV, Mycobacterium tuberculosis (Mtb) is the major cause of death. Due to the increased morbidity/mortality in co-infection, further research is urgently required. A limiting factor to research in HIV and HIV/Mtb co-infection is the lack of accessible in vivo models. Next-generation humanized mice expressing HLA transgenes report improved human immune reconstitution and functionality, which may better recapitulate human disease. This study compares well-established huNRG mice and next-generation HLA I/II-transgenic (huDRAG-A2) mice for immune reconstitution, disease course, and pathology in HIV and TB. HuDRAG-A2 mice have improved engraftment of key immune cell types involved in HIV and TB disease. Upon intravaginal HIV-1 infection, both models developed significant HIV target cell depletion in the blood and tissues. Upon intranasal Mtb infection, both models sustained high bacterial load within the lungs and tissue dissemination. Some huDRAG-A2 granulomas appeared more classically organized, characterized by focal central necrosis, multinucleated giant cells, and foamy macrophages surrounded by a halo of CD4+ T cells. HIV/Mtb co-infection in huNRG mice trended towards worsened TB pathology and showed potential for modeling co-infection. Both huNRG and huDRAG-A2 mice are viable options for investigating HIV and TB, but the huDRAG-A2 model may offer advantages