Unicentric Castleman Disease: Updates and Novel Insights Into Spindle Cell Proliferations and Aggressive Forms of a Localized Disease.

Castleman Disease (CD) is a rare lymphoproliferative disorder that can be separated into two primary forms: Unicentric Castleman disease (UCD) and multicentric Castleman disease (MCD). UCD is localized, while MCD is systemic. Though UCD generally has a favorable prognosis following surgical resection, more aggressive forms of this disease have been identified, including cases associated with dendritic and spindle cell proliferation.

Severe Hemolysis in a COVID-19 Patient with Paroxysmal Nocturnal Hemoglobinuria.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19), has been demonstrated to be able to activate complement, making patients with deficiency in negative complement regulation, such as paroxysmal nocturnal hemoglobinuria (PNH), particularly vulnerable to complement-mediated cell damage. We report a case of a patient who presented with fatigue, facial swelling, and upper respiratory infection (URI) symptoms and was found to have COVID-19 with laboratory tests showing severe hemolysis and pancytopenia secondary to PNH.

SMARCA4 (BRG1) and SMARCB1 (INI1) expression in TTF-1 negative neuroendocrine carcinomas including merkel cell carcinoma.

SMARCA4 and SMARCB1 loss of function has been implicated in many different tumors. The objective of this study was to investigate the loss of BRG1 and INI1 expression in TTF-1 negative neuroendocrine carcinomas to see if they are analogous to small-cell carcinoma of the ovary, hypercalcemic type. The potential role of these tumor suppressor genes in high-grade neuroendocrine carcinoma largely remains unknown.

Prevalence of Lymphoid Neoplasia in a Retrospective Analysis of Warthin Tumor: A Single Institution Experience.

Warthin tumor is one of the most common benign salivary gland tumors. Overt lymphoma is known to occur in the lymphoid stroma of Warthin tumor. In situ follicular neoplasia is difficult to identify in routine histologic examination of lymphoid tissue and has not been reported in association with Warthin tumor.