Synchronous Bilateral Ovarian Carcinomas With Right Mesonephric-like Adenocarcinoma and Left High-grade Serous Carcinoma: A Case Report and Review of the Literature.

Mesonephric-like adenocarcinomas (MLAs) are rare neoplasms of the uterus corpus and ovary, while high-grade serous carcinoma (HGSC) is the most common and lethal epithelial ovarian malignancy. We report a case of a 56-yr-old woman who presented with bilateral solid and cystic ovarian masses. She underwent a total abdominal hysterectomy with bilateral salpingo-oophorectomy, lymphadenectomy, omentectomy, and peritoneal biopsies.

Histopathologic, genomic, transcriptomic, and functional characteristics of eight melanocytic tumors with BRAF fusions showing stronger MAPK pathway activation compared to BRAF V600E tumors.

Background: Activating BRAF gene alterations are central to melanocytic tumor pathogenesis. A small, emerging subset of melanocytic tumors driven by BRAF fusions has distinct therapeutic implications and has been described to have Spitzoid morphology patterns. However, such morphological patterns do not encompass all cases, and little is known about the functional molecular events.

NTRK expression is common in xanthogranuloma and is associated with the solitary variant.

Background: Previously identified mutually-exclusive driver genes in juvenile xanthogranuloma (JXG) and adult xanthogranuloma (AXG) include mutations in MAP kinase pathway genes such as MAP2K1, BRAF, ARAF, KRAS, NRAS, PIK3CD as well as fusions in BRAF and ALK, with a subset of cases with no identified driver yet. NTRK fusion has been identified in rare cases.

Methods: We identified two consecutive index cases of localized JXG or AXG with NTRK1 fusion by next-generation sequencing (NGS) and confirmed by pan-NTRK immunostain.

Keratoacanthoma centrifugum marginatum.

Keratoacanthoma centrifugum marginatum (KCM) is an uncommon variant of keratoacanthoma. Keratoacanthoma centrifugum marginatums are most commonly seen on sun-exposed surfaces and present with progressive peripheral expansion and raised, hyperkeratotic borders. Central clearing with atrophy and lack of spontaneous clearance are other key clinical characteristics.

The utility of PRAME immunohistochemistry in the evaluation of challenging melanocytic tumors.

Background: PRAME (PReferentially expressed Antigen in Melanoma) immunohistochemistry has demonstrated high specificity for unequivocal melanomas; however, its utility in ambiguous melanocytic neoplasms has yet to be fully elucidated.

Methods: Cases of challenging melanocytic neoplasms were subclassified into one of three categories: challenging, favor benign (FB), challenging, cannot be subclassified (CCS), or challenging, favor malignant (FM). Using a previously published system, whereby cases with diffuse staining (>75%) were considered positive, scoring of PRAME was performed.

Utility of CK7 Versus p16 as a Prognostic Biomarker in CIN 2.

Cervical intraepithelial neoplasia (CIN) 2 is an equivocal diagnosis, with p16 immunohistochemical positivity currently recommended for diagnostic confirmation. Biomarkers characteristic of squamocolumnar junction cells were recently found to be positive in almost all CIN 2 and CIN 3. CIN 1 lesions which express squamocolumnar junction markers (in particular cytokeratin 7 [CK7]) are associated with a higher rate of subsequent high-grade squamous intraepithelial lesion, suggesting that CK7 may be a useful prognostic biomarker for CIN 1.