Sebaceomas in a Muir-Torre-like Phenotype in a Patient with MUTYH-Associated Polyposis.

This case report describes a case of a patient with MUTYH-associated polyposis (MAP), who presented with multiple sebaceomas in a Muir-Torre-like phenotype. MAP is caused by mutations in MUTYH, a base excision repair gene responsible for detecting and repairing the 8-oxo-G:A transversion caused by reactive oxygen species. MAP is associated with an increased risk of developing adenomatous polyps and colorectal cancer. Muir-Torre syndrome is a clinical phenotype of Lynch syndrome, which presents with multiple cutaneous sebaceous neoplasms. Lynch syndrome, like MAP, increases the likelihood of developing colorectal cancer but with a different pathogenesis and mode of inheritance. This case demonstrates that in a patient presenting with multiple sebaceous neoplasms, further workup and genetic testing may be indicated, not only for Muir-Torre and Lynch syndrome but also for MAP.

Concordance of Squamous Cell Carcinoma Histologic Grading Among Dermatopathologists and Mohs Surgeons.

BACKGROUND: Current staging systems for cutaneous squamous cell carcinoma (cSCC) incorporate histologic grade. There are no universally agreed on criteria to define differentiation for cSCC. OBJECTIVE: To determine the interrater and intrarater reliability among dermatopathologists and Mohs surgeons in grading histological differentiation for cSCC. METHODS AND MATERIALS: One hundred thirty-one archived slides were selected. Three dermatopathologists and 3 Mohs surgeons graded the tumors in a blinded manner (Round 1). In an attempt to improve concordance, all 6 participants were then asked to regrade the tumors based on a devised quantitative grading scale (Round 2). RESULTS: For Round 1, overall κ was 0.56 corresponding to a weak agreement. κ for well, moderate, and poorly differentiated tumors was 0.68, 0.39, and 0.59, respectively, corresponding to moderate, minimal, and weak concordance. For Round 2 of the study, overall κ was 0.60, with κ = 0.75, 0.46, and 0.61 for well, moderate, and poorly differentiated tumors, respectively. Overall intrarater reliability was 0.70 (κ = 0.70, 0.77, 0.68, 0.71, 0.56, and 0.75), corresponding to a moderate concordance. CONCLUSION: Overall concordance for cSCC histologic grading is weak to moderate among the experimental group. Substantial differences in concordance exist among histological degrees of differentiation, with lowest agreement in moderately differentiated tumors.

Folliculocentric Lichen Sclerosus et Atrophicus in a 10-Year-Old Girl.

Lichen sclerosus et atrophicus (LSA) is a chronic inflammatory scarring disease with a predilection for the anogenital area; however, 15%-20% of LSA cases are extragenital. The folliculocentric variant is rarely reported and less well understood. The authors report a rare case of extragenital, folliculocentric LSA in a 10-year-old girl. The patient presented to the dermatology clinic for evaluation of an asymptomatic eruption of the arms and legs, with no vaginal or vulvar involvement. Physical examination revealed the presence of numerous 2-4 mm, mostly perifollicular, hypopigmented, slightly atrophic papules and plaques. Many of the lesions had a central keratotic plug. Cutaneous histopathological examination showed features of LSA. Based on clinical and histological findings, folliculocentric extragenital LSA was diagnosed.

Superficial acral fibromyxoma and other slow-growing tumors in acral areas.

Superficial acral fibromyxoma (SAFM) is a rare fibromyxoid mesenchymal tumor with a predilection for the distal extremities and frequent nail bed involvement. Superficial acral fibromyxoma typically arises as a solitary, slow-growing nodule on a toe or finger, with the great toe being the most commonly affected site. Histopathologically, SAFM characteristically presents as a well-circumscribed but unencapsulated dermal tumor composed of spindle and stellate cells in a loose storiform or fascicular arrangement embedded in a myxoid, myxocollagenous, or collagenous stroma. The tumor often occupies the entire dermis and may extend into the subcutis and occasionally the underlying fascia and bone. The characteristic immunohistochemical profile of SAFM includes expression of CD34, epithelial membrane antigen (EMA), and CD99; it is notably negative for S-100 protein. We report 3 cases of SAFM and also provide a review of the literature on the clinical and histopathologic presentations of this unique entity as well as the differential diagnosis.

Kickbacks, stark violations, client billing, and joint ventures: facts and controversies.

Many current business trends in the field of dermatopathology deserve ethical scrutiny. An important point to consider in these analyses is that which is legal is not necessarily ethical. We examine the topics of client billing, contractual joint ventures, and health information technology donations, including both the legal implications as pertaining to the Stark Law and Anti-Kickback Statute, and the ethical ramifications of these practices.

Longitudinal melanonychia: detection and management of nail melanoma.

Malignant melanoma of the nail confers a higher mortality rate compared to other cutaneous melanomas, which is often attributable to delayed diagnosis. Two-thirds of nail melanomas present as longitudinal melanonychia (LM), longitudinally-oriented brown-black bands of pigment in the nail plate. This article delineates the appropriate clinical approach toward evaluation and management of a patient with longitudinal melanonychia, which includes determining risk factors for melanoma, recognizing scenarios in which biopsy is indicated, selecting the appropriate biopsy technique, and managing a patient in whom the diagnosis of nail melanoma has been made.