Endocrine mucin-producing sweat gland carcinoma: a systematic review and meta-analysis.

BACKGROUND: Endocrine mucin-producing sweat gland carcinoma is a rare, under-reported cutaneous adnexal tumor that is often misdiagnosed and has an unknown incidence of metastasis. OBJECTIVE: To determine the incidence of metastasis and tumor recurrence, as well as diagnostic accuracy and current trends in treatment modality. METHODS: A search was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Tumor pathology and clinical data concerning demographics, presentation, diagnosis, treatment and follow-up were assessed. RESULTS: A total of 36 publications with 110 cases were identified. Initial pathological diagnosis was incorrect in 45.5% of cases. One case of metastatic disease was reported. The incidence of locoregional recurrence was 10.6% over a mean follow-up period of 21.3 months. Of cases with known methods of resection, 34.6% were resected by excisional biopsy, 42.8% were resected by wide surgical excision, and 31.3% were cleared by Mohs micrographic surgery. LIMITATIONS: The low reported incidence and level of evidence was suboptimal with only case reports and retrospective case studies being reported. CONCLUSION: Reported cases of this pathology demonstrate poor diagnostic accuracy. High rates of misdiagnosis and inadequate definitive treatment suggest the need for more comprehensive work-up and management of lesions suspicious for this pathology.

A case of Gerstmann-Straussler-Scheinker (GSS) disease with supranuclear gaze palsy.

BACKGROUND: Gerstmann-Straussler-Scheinker disease (GSS), an autosomal dominant prion disorder, usually presents as a slowly progressive cerebellar ataxia followed by later cognitive decline. We present a member of the GSS Indiana Kindred with supranuclear palsy, a less common feature in GSS. CASE PRESENTATION: A 42-year-old man presented with 12 months of progressive gait and balance difficulty. Exam was notable for ataxia and cerebellar eye movement abnormalities. Genetic testing revealed a F198S variant in the prion protein (PRNP) gene, the pathological variant of GSS associated with his family, the Indiana kindred. Eighteen months after initial presentation supranuclear palsy developed. CONCLUSIONS: GSS is a neurodegenerative prion disease with diverse clinical presentations, and exhibits greater variability in disease phenotype compared to other inherited spongiform encephalopathies. GSS should be on the differential for patients with ataxia and supranuclear palsy, and it is important to assess both horizontal and vertical saccades and optokinetic nystagmus in patients with ataxia.