Syringocystadenoma Papilliferum of the Anogenital Area and Buttocks: A Report of 16 Cases, Including Human Papillomavirus Analysis and HRAS and BRAF V600 Mutation Studies.

Syringocystadenoma papilliferum (SCAP) is a benign tumor most commonly located on the head and neck area often associated with nevus sebaceus. In its usual location, the human papillomavirus (HPV) DNA and mutations in the RAS/mitogen-activated protein kinase signaling pathway have been detected in SCAP. We studied 16 cases of SCAP in the anogenital areas and buttock where this neoplasm is rare and attempted to find out whether SCAP in these sites have different histopathological and molecular biological features.

Sebaceous Neoplasms With Rippled, Labyrinthine/Sinusoidal, Petaloid, and Carcinoid-Like Patterns: A Study of 57 Cases Validating Their Occurrence as a Morphological Spectrum and Showing No Significant Association With Muir-Torre Syndrome or DNA Mismatch Repair Protein Deficiency.

Sebaceous neoplasms with an organoid pattern (rippled, labyrinthine/sinusoidal, carcinoid-like, and petaloid) are rare. Previous studies suggested that the above patterns likely represent variations along a morphological continuum. The objectives of this study were to (1) validate this proposition by studying a large number of cases, (2) determine whether there are specific associations with clinical features, (3) establish their frequency, and (4) determine whether they have any association with Muir-Torre syndrome.

Small Subset of Adenoid Cystic Carcinoma of the Skin Is Associated With Alterations of the MYBL1 Gene Similar to Their Extracutaneous Counterparts.

Adenoid cystic carcinoma (ACC) of the skin is a rare malignant neoplasm histologically identical to homonymous tumors in other organs. Cutaneous ACC has been found to harbor MYB gene activations, either through MYB chromosomal abnormalities or by generation of the MYB-NFIB fusion. In salivary gland ACC, in addition to the MYB gene, alterations in MYBL1, the gene closely related to MYB, have been reported.

ALK Gene Fusions in Epithelioid Fibrous Histiocytoma: A Study of 14 Cases, With New Histopathological Findings.

Previous studies showed that ALK is often positive in epithelioid fibrous histiocytoma (EFH). Two cases of EFH with ALK gene fusions have been recorded. Our objective was to study a series of EFH to present histopathological variations of EFH, identify novel ALK gene fusions, and determine whether there is a correlation between histopathological features and particular gene.

A Case of Lymphomatoid Papulosis Type E With an Unusual Exacerbated Clinical Course.

Lymphomatoid papulosis (LyP) type E is a recently delineated variant characterized by the occurrence of large necrotic "eschar"-like lesions displaying microscopically angioinvasive and angiodestructive infiltrates composed of CD30 lymphocytes, frequently coexpressing CD8. In contrast to other LyP variants where patients develop multiple lesions, most patients with LyP type E present with few lesions (often 1 or 2 at a given time). In this article, we describe a 34-year-old man with LyP type E with an exacerbated clinical course characterized by the occurrence of almost a hundred of lesions.

Spectrum of Changes in Anogenital Mammary-like Glands in Primary Extramammary (Anogenital) Paget Disease and Their Possible Role in the Pathogenesis of the Disease.

To determine whether a subset of primary extramammary Paget disease (EMPD) may originate in anogenital mammary-like glands (AGMLG), the authors studied 181 specimens of EMPD, detailing alterations in AGMLG. The latter were identified in 33 specimens from 31 patients. All patients were women, ranging in age from 38 to 93 years (median, 65 y).

Basal Cell Carcinoma With Matrical Differentiation: Clinicopathologic, Immunohistochemical, and Molecular Biological Study of 22 Cases.

Basal cell carcinoma (BCC) with matrical differentiation is a fairly rare neoplasm, with about 30 cases documented mainly as isolated case reports. We studied a series of this neoplasm, including cases with an atypical matrical component, a hitherto unreported feature. Lesions coded as BCC with matrical differentiation were reviewed; 22 cases were included.

Squared-Off Nuclei and "Appliqué" Pattern as a Histopathological Clue to Periocular Sebaceous Carcinoma: A Clinicopathological Study of 50 Neoplasms From 46 Patients.

The histopathological diagnosis of periocular sebaceous carcinoma can be difficult in poorly differentiated cases showing few mature sebocytes. The authors examined 50 periocular sebaceous carcinomas from 46 patients to determine the frequency of 2 features seen in this neoplasm, namely cells with squared-off nuclei and so-called "appliqué" pattern (peritumoral subnecrosis of peripherally located neoplastic cells). Neoplastic cells with squared-off nuclei were found in varying numbers in both the intraepithelial and dermal (invasive) components in all neoplasms, whereas the appliqué pattern was observed in a third of the cases.

Anogenital Mammary-Like Glands: A Study of Their Normal Histology With Emphasis on Glandular Depth, Presence of Columnar Epithelial Cells, and Distribution of Elastic Fibers.

The normal histology of anogenital mammary-like glands (AGMLG) has been studied previously, but some aspects, including glandular depth, presence of columnar epithelium resembling columnar cell change/hyperplasia as defined in mammary pathology, and distribution of elastic fibers, have not been previously investigated. To address these issues, we studied 148 AGMLG identified in 133 paraffin blocks sampled from 64 vulvar wide excision or vulvectomy specimens (64 patients, various indications for surgery). The depth of AGMLG ranged from 0.

Depth and Patterns of Adnexal Involvement in Primary Extramammary (Anogenital) Paget Disease: A Study of 178 Lesions From 146 Patients.

Extramammary Paget disease (EMPD) is a rare neoplasm usually presenting in the anogenital area, most commonly in the vulva. Adnexal involvement in primary EMPD is a very common feature and serves as a pathway for carcinoma to spread into deeper tissue. The depth of carcinomatous spread along the appendages and the patterns of adnexal involvement were studied in 178 lesions from 146 patients with primary EMPD.

An Immunohistochemical Study of Anogenital Mammary-Like Glands.

Although the normal histology of anogenital mammary-like glands (AGMLG) has been studied, no systemic investigation has been performed on the immunoprofile of these structures. We studied intact AGMLG with a broad panel of antibodies. The immunoprofile of AGMLG is similar to that of a normal breast tissue, and there are similarities to eccrine glands and coils about cytokeratin expression.

Cutaneous hidradenoma: a study of 21 neoplasms revealing neither correlation between the cellular composition and CRTC1-MAML2 fusions nor presence of CRTC3-MAML2 fusions.

Twenty-one hidradenomas from 20 patients (13 female, 7 male) ranging in age from 18 to 87years (mean, 57.75years; median, 60years) were studied for CRTC1-MAML2 and CRTC3-MAML2 fusions to find out whether there is a correlation between the particular cell type (polyhedral eosinophilic, clear, mucinous, epidermoid, and oncocytic) and presence the above alterations. CRTC1-MAML2 fusions were detected in 10 of the 21 neoplasms (47.