Pleomorphic Adenoma with a Novel Gene Rearrangement-LINC01606::PLAG1.

BACKGROUND: Pleomorphic adenoma is a well-known benign salivary gland neoplasm characterized by the presence of varying proportions of three different components, including bi-layered ducts, myoepithelial cells, and admixed within a chondromyxoid/fibrous stroma. METHOD: We report an interesting case of an adult male who presented with bleeding from an extensively degenerated parotid gland mass, concerning for a vascular neoplasm versus primary malignant tumor. Microscopically, majority of the viable tumor exhibited diffuse proliferation of spindle to epithelioid cells, with focal areas depicting cribriform glands, ducts, and scant chondromyxoid stroma. RESULT: Next-generation sequencing (NGS) RNA-based fusion panel analysis identified a gene rearrangement involving the pleomorphic adenoma gene 1 (PLAG1), with a novel, cryptogenic fusion partner known as LINC01606; [LINC01606::PLAG1; inv(8;8)(8q12.1;8q12.1)]. CONCLUSION: To the best of our knowledge, this is the first documented case of a long non-coding RNA (lnc-RNA) serving as a rearrangement partner with the PLAG1 gene. We reviewed the molecular characteristics of this entity and explored the potential role of LINC01606::PLAG1 in the tumorigenesis of pleomorphic adenoma.

Fatal Hemophagocytic Lymphohistiocytosis Resulting in the Death of a Previously Healthy 49-Year-Old Man in Ten Days.

Hemophagocytic lymphohistiocytosis (HLH) is an aggressive, life-threatening condition with sudden onset of a systemic inflammatory response syndrome. The triggers can be apparently non-specific, and the clinical presentations can be very deceptive during a rapidly deteriorating clinical course. Herein, we report a case of a 49-year-old White/Caucasian male with no known past medical history who presented with multi-organ failure, including liver, kidney, and bone marrow, along with disseminated intravascular coagulation. He had a high probability of HLH. Unfortunately, he died ten days after the initial presentation. At autopsy, the liver was necrotic and immunostains revealed diffuse positivity for HSV-1 & 2. The bone marrow was markedly hypocellular with phagocytes containing intact and fragmented red blood cells. There was also disseminated fungal infection involving almost all tissues. PCR, done on frozen tissue samples, revealed Aspergillus fumigatus. The rapid and fatal course of this patient illustrates the sometimes-aggressive course of HLH and the importance of autopsy examination in revealing the underlying etiology for this patient's death.

Uterine Carcinosarcoma Presenting as Metastatic Osteosarcoma in the Lung: A Case Report and Literature Review.

Uterine carcinosarcomas (UCS) are aggressive tumors characterized by their biphasic nature, consisting of high-grade epithelial and mesenchymal elements. One component may predominate over the other. We present the case of a 59-year-old female who initially received a diagnosis of endometrial serous carcinoma and presented one year later with a malignant neoplasm in the lung featuring osteosarcomatous differentiation. Notably, the bone scan did not reveal any evidence of a primary bone tumor. However, additional sampling from the endometrium demonstrated a UCS with an osteosarcomatous component.Upon reviewing existing literature, it has been observed that metastases in carcinosarcoma cases generally arise from the carcinomatous component. Conversely, the sarcomatous component typically spreads locally to areas such as the vagina, cervix, or fallopian tubes. The presented case stands out as a unique instance of an undiagnosed UCS manifesting as metastatic osteosarcoma in the lung. This case underscores the complexity and diverse presentations of UCS and emphasizes the importance of comprehensive evaluation in understanding its clinical manifestations.