Endocrine Mucin-Producing Sweat Gland Carcinoma and Primary Cutaneous Mucinous Carcinoma: A Case Series.

Endocrine mucin-producing sweat gland carcinoma (EMPSGC) and primary cutaneous mucinous carcinoma (PCMC) are rare low-grade neoplasms thought to arise from apocrine glands that share many histological features and are proposed to be on a single histopathologic continuum, with EMPSGC as the in situ form that may progress to the invasive PCMC. Management involves a metastatic workup and either wide local excision (WLE) with greater than 5 mm margins or Mohs micrographic surgery (MMS) in anatomically sensitive areas. We present 2 cases of EMPSGC and 3 cases of PCMC and review their clinical and histopathologic features, differential diagnoses, and treatment.

Intravascular histiocytosis: mimicker of cellulitis, angiosarcoma, inflammatory breast cancer, and others.

BACKGROUND: Intravascular histiocytosis is an underrecognized reactive skin condition characterized by the clinical finding of poorly demarcated erythematous to violaceous patches and plaques. The diagnosis is confirmed by the histologic findings of intraluminal histiocytes on skin biopsy and exclusion of an alternative diagnosis. METHODS: A review of patients with a histologic diagnosis of intravascular or intralymphatic histiocytosis and seen at Mayo Clinic, Rochester, Minnesota, from January 1, 2010, to October 10, 2020, was performed. Histologic and clinical information was collected from the medical records. RESULTS: Nine patients were identified. Clinical impressions prior to biopsy varied widely, and no clinician included intravascular histiocytosis in the initial clinical differential diagnosis. Eight patients had preceding trauma to the affected area. CONCLUSION: Intravascular histiocytosis remains a rare skin condition. Clinical identification remains low. Our cases add support to the hypothesis that intravascular histiocytosis is a reactive condition often preceded by trauma and/or surgery.

Atypical fibroxanthoma: Systematic review and meta-analysis of treatment with Mohs micrographic surgery or excision.

BACKGROUND: Atypical fibroxanthoma (AFX) is a fibrohistiocytic tumor with relatively high local recurrence rates but low metastatic potential. Wide local excision (WLE) and Mohs micrographic surgery (MMS) are common treatments, although no consensus exists regarding optimal therapy. OBJECTIVE: To systematically review evidence of AFX recurrence and metastatic rates after different surgical modalities. METHODS: A comprehensive search was performed for articles published from 1946 or database inception to March 20, 2017. Studies selected included those that had 5 or more patients with atypical fibroxanthoma treated surgically. Two reviewers independently abstracted the data. Risk of bias was assessed with the Newcastle-Ottawa scale. Main outcomes and measures included recurrence and metastasis. RESULTS: In total, 23 studies were selected (907 patients and 914 tumors); 175 patients were treated with MMS (recurrence rate 2.0%, 95% confidence interval [CI] 0%-4.1%; metastatic rate 1.9%, 95% CI 0.1%-3.8%), and 732 were treated with WLE (recurrence rate 8.7%, 95% CI 5%-12.3%; metastasis rate 1%, 95% CI 0.2%-1.9%). Among immunocompromised patients, no recurrence or metastases developed in the MMS subgroup, although 4 of 10 recurred and 1 of 10 metastasized in the WLE subgroup. LIMITATIONS: Low quality of the studies published. CONCLUSION: MMS for atypical fibroxanthoma is associated with a lower recurrence rate than WLE.

Risk Factors for Cutaneous Squamous Cell Carcinoma Recurrence, Metastasis, and Disease-Specific Death: A Systematic Review and Meta-analysis.

IMPORTANCE: To date, the magnitude of association and the quality of evidence for cutaneous squamous cell carcinoma (cSCC) and risk factors for outcomes have not been reviewed and analyzed systematically. OBJECTIVE: To systematically analyze all published data on risk factors for recurrence, metastasis, and disease-specific death (DSD) of cSCC. DATA SOURCES: Comprehensive search of Ovid MEDLINE In-Process & Other Non-Indexed Citations, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus, from each database's inception to May 14, 2015. STUDY SELECTION: Inclusion criteria were studies of at least 10 patients, comparative data for at least 1 cSCC risk factor, and an outcome of interest. Exclusion criteria were noncutaneous squamous cell carcinoma (SCC), anogenital SCC, inability to extract cSCC data from other malignancy data, SCC in situ, Marjolin ulcer, and genetic disorders predisposing to cSCC. DATA EXTRACTION AND SYNTHESIS: Two reviewers independently abstracted the data. Meta-analysis was performed using the random-effects model. Risk of bias was assessed by the Newcastle-Ottawa Scale. MAIN OUTCOMES AND MEASURES: A priori outcomes were recurrence, metastasis, and DSD. RESULTS: Thirty-six studies (17 248 patients with 23 421 cSCCs) were included. Significant risk factors for recurrence were the following: Breslow thickness exceeding 2 mm (risk ratio [RR], 9.64; 95% CI, 1.30-71.52), invasion beyond subcutaneous fat (RR, 7.61; 95% CI, 4.17-13.88), Breslow thickness exceeding 6 mm (RR, 7.13; 95% CI, 3.04-16.72), perineural invasion (RR, 4.30; 95% CI, 2.80-6.60), diameter exceeding 20 mm (RR, 3.22; 95% CI, 1.91-5.45), location on the temple (RR, 3.20; 95% CI, 1.12-9.15), and poor differentiation (RR, 2.66; 95% CI, 1.72-4.14). Significant risk factors for metastasis were: invasion beyond subcutaneous fat (RR, 11.21; 95% CI, 3.59-34.97), Breslow thickness exceeding 2 mm (RR, 10.76; 95% CI, 2.55-45.31), Breslow thickness exceeding 6 mm (RR, 6.93; 95% CI, 4.02-11.94), diameter exceeding 20 mm (RR, 6.15; 95% CI, 3.56-10.65), poor differentiation (RR, 4.98; 95% CI, 3.30-7.49), perineural invasion (RR, 2.95; 95% CI, 2.31-3.75), immunosuppression (RR, 1.59; 95% CI, 1.07-2.37), and location on the temple (RR, 2.82; 95% CI, 1.72-4.63), ear (RR, 2.33; 95% CI, 1.67-3.23), or lip (RR, 2.28; 95% CI, 1.54-3.37). Significant risk factors for DSD were: diameter exceeding 20 mm (RR, 19.10; 95% CI, 5.80-62.95), poor differentiation (RR, 5.65; 95% CI, 1.76-18.20), location on the ear (RR, 4.67; 95% CI, 1.28-17.12) or lip (RR, 4.55; 95% CI, 1.41-14.69), invasion beyond subcutaneous fat (RR, 4.49; 95% CI, 2.05-9.82), and perineural invasion (RR, 4.06; 95% CI, 3.10-5.32). Evidence quality was considered low to moderate. CONCLUSIONS AND RELEVANCE: Tumor depth is associated with the highest RR of local recurrence and metastasis of cSCC, and tumor diameter exceeding 20 mm is associated with the highest RR of DSD. Unified, consistent collection and reporting of risk factors in a prospective, multicentered effort are needed to further understand the increasing incidence of cSCC.