Histologic Hitchhikers: A Review of Common Exogenous Artifacts Encountered During Mohs Micrographic Surgery.

BACKGROUND: Exogenous artifacts can interfere with accurate histologic tissue evaluation on frozen sections during Mohs micrographic surgery (MMS). Mohs surgeons should be aware of these anomalies to avoid potential misdiagnoses. OBJECTIVE: To review exogenous artifacts encountered in frozen tissue pathology during MMS. METHODS: A literature search was conducted in PubMed to identify studies reporting on exogenous artifacts encountered during MMS and a list of previously described exogenous artifacts was compiled. A retrospective examination of frozen histology slides from recent Mohs cases at the authors' institution was performed to obtain illustrative examples of these artifacts, supplemented by formalin-fixed paraffin-embedded samples when frozen examples could not be found. RESULTS: Exogenous artifacts represent foreign bodies that have been externally introduced into the skin or artifacts resulting from other external factors. If frozen section evaluation is inaccurate, overdiagnosis can occur during MMS, resulting in unnecessary layers, larger margins, and more complex reconstructions. These exogenous tissue changes can mimic inflammatory processes and melanocytic or keratinocyte malignancies on histology. CONCLUSION: Exogenous artifacts are common findings during margin assessment in Mohs micrographic surgery. The resulting histological findings can be confusing but correlating them with the clinical and surgical history often reassures surgeons. Recognizing these artifacts facilitates accurate diagnosis and promotes optimal patient care.

Treatment of Periorbital Vascularity, Erythema, and Hyperpigmentation.

Periorbital hyperpigmentation (POH) is a common aesthetic concern that impacts patients' emotional well-being and quality of life. POH can be difficult to manage as the etiology is often multifactorial or difficult to elucidate. An understanding of different contributing factors and ability to classify hyperpigmentation can aid in the management of POH. Classification of POH is divided into pigmented, vascular, structural, and mixed subtypes. A wide array of treatment options has been proposed belying the challenges inherent to improving POH. Modalities vary from topical therapies, chemical peels, dermal fillers, and lasers, to surgical intervention. Because POH can be multifactorial, successful management of POH will depend on elucidating the etiology and often requires a combination of therapies.

Syringotropic Mycosis Fungoides: A Variant of Folliculotropic or a Distinct Subtype of Adnexotropic Mycosis Fungoides?

Mycosis fungoides (MF) is a slowly progressive form of cutaneous T-cell lymphomas (CTCL). MF is classified into 4 subtypes including folliculotropic MF (FMF). Infiltration of both hair follicles and eccrine glands is included in the FMF classification and designated as syringotropic MF (STMF), an exceedingly rare form of CTCL. We report an additional case of STMF. The clinical course of syringotropic CTCL is more benign than FMF, suggesting that despite similar clinical presentations, they are molecularly distinct diseases. Clinical characteristics can help differentiate STMF from FMF. Skin-directed therapies are less effective in STMF than FMF. With distinct clinical characteristics, histopathologic findings, and disease course, syringotropic CTCL should be considered a subtype entity in the spectrum of adnexotropic MF. J Drugs Dermatol. 2022;21(12):1362-1364. doi:10.36849/JDD.6779.

Treatment of Periorbital Vascularity, Erythema, and Hyperpigmentation.

Periorbital hyperpigmentation (POH) is a common aesthetic concern that impacts patients' emotional well-being and quality of life. POH can be difficult to manage as the etiology is often multifactorial or difficult to elucidate. An understanding of different contributing factors and ability to classify hyperpigmentation can aid in the management of POH. Classification of POH is divided into pigmented, vascular, structural, and mixed subtypes. A wide array of treatment options has been proposed belying the challenges inherent to improving POH. Modalities vary from topical therapies, chemical peels, dermal fillers, and lasers, to surgical intervention. Because POH can be multifactorial, successful management of POH will depend on elucidating the etiology and often requires a combination of therapies.

Erythema ab igne in patients with sickle cell disease.

Erythema ab igne (EAI) is an asymptomatic dermatosis caused by prolonged exposure to localized heat. Affected areas have net-like hyperpigmentation that may resemble more serious conditions such as livedo racemosa or vasculitis. We report three cases of EAI in pediatric sickle cell disease (SCD) patients who were initially suspected of having a more severe, life-threatening disorder before Dermatology was consulted. Clinicians caring for pediatric SCD patients who regularly use heating pads/devices for pain relief should consider EAI in the differential diagnosis of large areas of net-like hyperpigmentation. This paper aims to increase recognition of EAI and patient education on safe practices while using heating pads.