Digital Papillary Adenocarcinoma in Nonacral Skin: Clinicopathologic and Genetic Characterization of 5 Cases.

Digital papillary adenocarcinoma (DPA) is a rare sweat gland neoplasm that has exceptionally been reported outside acral locations. Recently, human papillomavirus 42 was identified as the main oncogenic driver of DPA. Herein, we report 5 tumors arising in extra-acral locations predominantly in the female anogenital skin. Four patients were female and 1 patient was male. The mean age at the diagnosis time was 65 years (range: 55 to 82 y). Tumors were located on the vulva (n=3), perianal area (n=1), and forearm (n=1). Histologically, all tumors were lobular and mainly solid and composed of sheets of cells with rare focal papillae and frequent glandular structures in a "back-to-back" pattern and lined by atypical basophilic cells. Immunohistochemistry showed diffuse positivity for SOX10. Epithelial membrane antigen and carcinoembryonic antigen highlighted the luminal cells and staining for p63 and p40 revealed a consistent and continuous myoepithelial component around glandular structures. Follow-up was available in 3 cases (mean duration: 12 mo [range: 8 to 16 mo]). One patient developed local recurrence and 1 experienced regional lymph node metastases. HPV Capture Next-generation sequencing revealed the presence of the HPV42 genome in all samples. Viral reads distributions were compatible in the 5 cases with an episomal nature of the viral genome, with a recurrent deletion in the E1 and/or E2 open reading frames. In conclusion, this study demonstrates that digital DPA may rarely present in nonacral locations mainly in the female anogenital area, usually with a more solid pattern as compared with those cases presenting on the digits and it is also associated with HPV42.

Subungual melanoma with blue naevus-like morphological features: a clinicopathological retrospective analysis of nine cases.

Melanocytic lesions in the nail apparatus are often challenging. Both subungual melanomas (SUM) and blue naevus of the nail are very rare. Occasionally, melanomas may mimic blue naevus histologically. Benign and malignant blue melanocytic lesions are commonly associated with G protein mutations, a distinct abnormality not associated with conventional subungual melanomas. We describe the clinical, histological and immunohistochemical features of nine cases of SUM with blue naevus-like morphological features. Mutations in exon 4 and 5 of GNAQ and GNA11 were investigated in two cases, which showed no mutations. RNA-seq of one case revealed unknown mutations along with mutations in ATM, METK and ARID1A. Our study delineates a variant of SUM that mimics blue naevus. Awareness of this pitfall is important when evaluating heavily pigmented lesions around the nail in order to avoid misdiagnosis. Appropriate sampling of subungual lesions and clinicopathological correlation are paramount to reach the correct diagnosis.

Squamoid Eccrine Ductal Carcinoma: A Clinicopathologic Study of 30 Cases.

Squamoid eccrine ductal carcinoma is a poorly documented skin adnexal carcinoma showing squamous and duct differentiation. It is regarded to be of low-grade malignant potential, but limited follow-up information is available. To study their clinical behavior and histologic features, 30 squamoid eccrine ductal carcinomas were identified from departmental and referral files. Hematoxylin and eosin-stained sections were reviewed, and immunohistochemistry for carcinoembryonic antigen and epithelial membrane antigen was examined to confirm duct differentiation. Clinical follow-up was obtained from patient records and referring pathologists. The tumors presented as nodules or plaques (median size, 1.0 cm; range, 0.5 to 2.5 cm) with a predilection for the head and neck (77%). The patients were elderly (median age, 79.5 y; range, 10 to 96 y) with a male predominance. Histologically, these poorly demarcated tumors were characterized by an infiltrative growth pattern within the dermis and additional invasion of subcutis in 70%. Median tumor thickness was 4.3 mm (range, 1.5 to 18 mm). Superficially, the tumors resembled well-differentiated squamous cell carcinoma. In the deeper reaches, they were organized in cords and strands showing duct differentiation in a desmoplastic stroma. Cytologic atypia was moderate to severe. Ulceration (47%), necrosis (23%), and perineural and lymphovascular infiltration (27% and 6%, respectively) were additional features. Follow-up data (median, 29 mo; range, 7 to 99), available for 24 patients (80%), revealed a local recurrence rate of 25%. Three patients had lymph node metastasis, and 1 patient died of metastatic disease. Our study outlines the histologic characteristics of squamoid eccrine carcinoma and emphasizes its clinical behavior with risk for local recurrence and potential for more aggressive behavior with metastasis and rare disease-related mortality.

Adolescent "Saxophone Penis" Secondary to Crohn's Disease: Misdiagnosed as Being Posttraumatic.

We describe a patient with a "saxophone penis" mistakenly diagnosed as having posttraumatic changes. A careful history and attention to blood tests at presentation may have alerted clinicians that there was a nontraumatic cause for our patient's disease. It is essential that clinicians consider "metastatic" anogenital Crohn's disease as a possible cause of "saxophone penis".

Seasonal cutaneous sarcoidosis: a photo-induced variant.

Sarcoidosis is a multisystem granulomatous disease, with cutaneous involvement in up to 35% of cases. Owing to its heterogeneous clinical presentation, sarcoidosis is often referred to as the 'great imitator' of dermatological disease. A rare variant of photosensitive cutaneous sarcoidosis has been infrequently reported in the literature. We describe an unusual case of recurrent, photo-distributed cutaneous sarcoidosis presenting only during the summer months.

Miofibroblastoma extramamario. A propósito de un casocon receptores de progesterona positivos en una mujerembarazada / A case report of extramammary myofibroblastoma with progesterone receptors in a pregnant woman

El miofibroblastoma mamario es un tumor benigno dedescripción relativamente reciente cuyas característicasmorfológicas, inmunofenotípicas y citogenéticas hacen queactualmente se considere íntimamente relacionado con ellipoma de células fusiformes y con el angiofibroma celular.La localización extramamaria es excepcional, con solo docecasos publicados hasta la fecha. Presentamos un nuevo casode miofibroblastoma extramamario situado en el brazo deuna mujer embarazada cuya peculiaridad radica en la expresiónde receptores de progesterona, característica que no hasido descrita anteriormente en la literatura (AU)

Mammary myofibroblastoma is a recently describedbenign tumour with morphological, immunophenotypic andcytogenetic features that suggest a close relation with spindlecell lipoma and cellular angiofibroma. An extramammarylocation is exceptionally rare, with only 12 casespublished to date. The present case is an extramammarymyofibroblastoma occuring in the arm of a pregnantwoman. The tumour was positive for progesterone receptors,a hitherto unreported finding (AU)