Progression of Low-Grade Neuroendocrine Tumors (NET) to High-Grade Neoplasms Harboring the NEC-Like Co-alteration of RB1 and TP53.

High-grade or grade 3 epithelial neuroendocrine neoplasms (G3 NEN) are now divided into grade 3 well-differentiated neuroendocrine tumor (G3 NET) and neuroendocrine carcinoma (NEC), both defined by Ki-67 > 20% and/or > 20 mitoses per 2 mm. NET and NEC are thought to be distinct tumors with different genetic profiles: NEC classically harbors co-alteration of TP53 and RB1, whereas NET genetics are site-dependent with frequent alterations in MEN1, ATRX, DAXX, and TSC1/2 in pancreatic NETs. Progression from NET to NEC is considered rare and is not well described.

A High-Grade Glioma, Not Elsewhere Classified in an Older Adult with Discordant Genetic and Epigenetic Analyses.

The World Health Organization's (WHO) classification of central nervous system (CNS) tumors is continually being refined to improve the existing diagnostic criteria for high-grade gliomas (HGGs), including glioblastoma. In 2021, advances in molecular analyses and DNA methylation profiling were incorporated to expand upon the diagnostic criteria for HGG, including the introduction of high-grade astrocytoma with piloid features (HGAP), a new tumor entity for which a match to the HGAP class in DNA methylation profiling is an essential criterion. We present an equivocal case of a 72-year-old male with an HGG exhibiting features of both HGAP and glioblastoma, but which did not conform to any existing 2021 WHO classification of CNS tumor entities.

Stromal Keratitis Associated With Cytomegalovirus Anterior Uveitis.

Purpose: Human cytomegalovirus (CMV) has commonly been reported as a cause of anterior uveitis and corneal endotheliitis. Unlike its other herpetic family members, herpes simplex virus and varicella zoster virus, involvement of the corneal stroma in CMV is uncommon. In this case series, we describe patients with CMV stromal keratitis.

Malignant melanotic nerve sheath tumor with PRKAR1A, KMT2C, and GNAQ mutations.

Malignant melanotic nerve sheath tumor (MMNST) is a rare and potentially aggressive lesion defined in the 2021 WHO Classification of Tumors of the Central Nervous System. MMNST demonstrate overlapping histologic and clinical features of schwannoma and melanoma. MMNST often harbor mutations, especially within the Carney Complex.

Leucocytoclastic vasculitis due to acute bacterial endocarditis resolves with antibiotics.

Infective endocarditis is associated with a variety of clinical signs, but its association with multisystem vasculitis is rarely reported. A high index of suspicion is necessary to differentiate a primary autoimmune vasculitis from an infectious cause as the wrong treatment can lead to significant morbidity and mortality. We present a 71-year-old female patient with negative blood cultures, on antibiotics for recent bacteraemia, who presented with cutaneous and renal leucocytoclastic vasculitis.

Transient Pigmentary Lines of the Newborn in a Postmortem Examination: A Case Report.

Sudden unexplained death in infancy is a leading cause of death among infants between 1 month and 1 year of age in the United States. The medical examiner is frequently given the difficult task of attempting to rule out other causes of death such as infantile trauma or child abuse. A thorough postmortem examination of the skin is a crucial component of the autopsy, as is sufficient knowledge of both benign and traumatic skin pathologies.