Perianal extramammary Paget disease treated with topical imiquimod and oral cimetidine.

Extramammary Paget disease (EMPD) is a rare intraepithelial adenocarcinoma. The current mainstay of treatment is wide local excision. We present the case of a 56-year-old woman with perianal EMPD that recurred 4 years after initial treatment with wide local excision with Mohs micrographic surgery tissue processing of marginal tissue. Upon recurrence with anal canal involvement, the patient was treated with a 16-week combination course of topical imiquimod and oral cimetidine. There is growing evidence to support both the use of topical imiquimod for the treatment of EMPD as well as the antioncogenic effects of oral cimetidine. We present this case of primary perianal EMPD to highlight an alternative treatment regimen for poor surgical candidates.

The microenvironment in primary cutaneous melanoma with associated spontaneous tumor regression: evaluation for T-regulatory cells and the presence of an immunosuppressive microenvironment.

Spontaneous tumor regression, regression in the absence of therapeutic intervention, can be identified histologically in over 25% of primary cutaneous melanomas at initial diagnosis. A unique subset of T lymphocytes found in areas of regression can be histologically distinguished from tumor-infiltrating T lymphocytes (TIL) found in areas of tumor progression. We call this unique subset of T lymphocytes regression-associated T lymphocytes (RATs). The aim of this study is to determine the phenotype of lymphocytes and the density of specific cell types linked to immunosuppression in areas of tumor progression compared with areas of tumor regression. These specific cell types include T-regulatory cells (Tregs) and S100A9 cells. A total of 14 primary cutaneous melanomas with areas of progression and regression were used. Immunohistochemistry staining was used to identify CD4 cells, CD8 cells, Tregs, and S100A9 cells. Two independent observers manually counted three high-powered ×40 fields. There was no predominance of CD4 or CD8 T lymphocytes in either RATs or TIL. We identified a lower density of Tregs in RATs compared with TIL when using the FOXP3/CD4 Treg marker (P=0.04) and a marginal difference when using our second, confirmatory Treg marker, FOXP3/CD25 (P=0.11). We observed a lower density of S100A9 cells in RATs compared with TIL (P=0.002). There was an observable difference in the tumor microenvironments of RATs and TIL, with RATs having a significantly lower density of Tregs and S100A9 cells. We deduce that the absence of immunosuppression in areas of regression allows for a more robust immune response and thus effective eradication of tumor cells.

Novel treatment of blastic plasmacytoid dendritic cell neoplasm: A case report.

RATIONALE: Blastic plasmacytoid dendritic cell neoplasm (BPDCN), derived from precursors of plasmacytoid dendritic cells, is a rare and aggressive malignancy with frequent cutaneous involvement. Although cutaneous lesions are often chemosensitive, BPDCN portends a poor prognosis as most patients relapse after developing drug resistance. PATIENT CONCERNS: We report a case of a 65-year-old man who presented with a rapidly enlarging hyperpigmented plaque on his shoulder with subsequent similarly appearing macules and plaques on his chest, back, and neck. DIAGNOSIS: Skin biopsy revealed a dense adnexocentric dermal infiltrate of immature blastoid cells without epidermal involvement. The infiltrate was immunoreactive for CD4, CD56, CD123, and Bcl-2, but negative for CD3, CD8, CD30, MPO, EBER, and ISH. The patient was diagnosed with BPDCN based on these cell markers. INTERVENTION: Bone marrow biopsy and radiologic work-up showed no evidence of extracutaneous involvement. The patient attained partial remission after undergoing 2 rounds of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP regimen) before autologous stem cell transplantation, however, he quickly relapsed and developed new cutaneous lesions. OUTCOMES: The patient was treated with venetoclax, a Bcl-2 inhibitor, and exhibits complete resolution of prior skin findings and continues to remain free of new cutaneous lesions 10 months posttreatment initiation with venetoclax. LESSONS: Herein, we present a case that supports the use of venetoclax, a Bcl-2 inhibitor, in the off-label treatment of BPDCN with Bcl-2 overexpression. Only 1 prior case has reported the off-label use of venetoclax for the treatment of BPDCN. This case highlights a novel therapeutic option for BPDCN patients unresponsive to traditional treatment.