Clinicopathologic and Molecular Characterization of NUP98-Rearranged Acute Leukemias.

Introduction: NUP98 rearrangements are rare in acute leukemias and portend a poor prognosis.

Methods: This study explored clinicopathologic and molecular features of five patients with NUP98 rearranged (NUP98-r) acute leukemias, including three females and two males with a median age of 34 years.

Results: NUP98 fusion partners were associated with distinctive leukemia characteristics and biology.

Cholangioblastic Cholangiocarcinoma (NIPBL::NACC1 cholangiocarcinoma): Expanded Morphologic Spectrum and Further Genetic Characterization.

The cholangioblastic variant of intrahepatic cholangiocarcinoma is a distinctive neoplasm that typically affects young women without underlying liver disease. Morphologically, it demonstrates solid, trabecular, and tubulocystic architecture, biphasic small cell-large cell cytology, and immunoreactivity for inhibin, neuroendocrine markers, and biliary but not hepatocellular markers. In 2021, our group identified a characteristic NIPBL::NACC1 gene fusion in cholangioblastic cholangiocarcinoma, and since then ~20 genetically confirmed cases have been reported in the literature.

Sialadenopapillary Ductal Tumors: Unifying the Spectrum of Sialadenoma Papilliferum-like Tumors With Low Malignant Potential.

Sialadenoma papilliferum is a tumor characterized by surface papillary projections and glandular/microcystic proliferation at the lesion base. Cases in which surface involvement is absent have been termed "sialadenoma papilliferum-like intraductal papillary tumor." Similar tumors that are present in the mandible have been termed "tubulopapillary hidradenoma-like tumor of the mandible.

MYB/MYBL1-altered gliomas frequently harbor truncations and non-productive fusions in the MYB and MYBL1 genes.

Astrocytomas that harbor recurrent genomic alterations in MYB or MYBL1 are a group of Pediatric-type diffuse low-grade gliomas that were newly recognized in the 2021 WHO Classification of Tumors of the Central Nervous System. These tumors are described in the WHO classification as harboring fusions in MYB or MYBL1. In this report, we examine 14 consecutive cases in which a MYB or MYBL1 alteration was identified, each with diagnostic confirmation by genome-wide DNA methylation profiling (6 Angiocentric gliomas and 8 Diffuse astrocytomas, MYB- or MYBL1-altered), for their specific genomic alterations in these genes.

Comprehensive Next Generation Sequencing Reveals that Purported Primary Squamous Cell Carcinomas of the Parotid Gland are Genetically Heterogeneous.

Squamous cell carcinoma (SCC) is one of the most common malignancies involving the parotid gland, but it has been recognized that the vast majority of parotid SCC represents metastases, especially from the ipsilateral facial skin. Bona fide primary SCC of the parotid is so rare that it is unclear whether it truly exists at all. We sought to molecularly characterize cases diagnosed as primary parotid gland SCC to see if they possess a unique genetic makeup.