COVID-19: Review of a 21st Century Pandemic from Etiology to Neuro-psychiatric Implications.

COVID-19 is a severe infectious disease that has claimed >150,000 lives and infected millions in the United States thus far, especially the elderly population. Emerging evidence has shown the virus to cause hemorrhagic and immunologic responses, which impact all organs, including lungs, kidneys, and the brain, as well as extremities. SARS-CoV-2 also affects patients', families', and society's mental health at large.

Retroperitoneal lymphatic malformation in a dog.

Background: Lymphatic vascular malformations are rare findings in canine patients with six reports available in veterinary literature. Retroperitoneal cystic lymphatic malformations have not been described previously in canine patients and neither has the use of immunohistochemistry to determine their origin, i.e.

Corneal invasion by hemangiosarcoma in a horse.

A 15-year-old gray Arabian gelding presented for evaluation of a lateral limbal mass extending across approximately 30% of the cornea. Grossly, the raised mass appeared nonpigmented, smooth, and irregular in shape, with an area of central necrosis and serosanguinous discharge. The mass was removed via lamellar keratectomy and histopathologic evaluation revealed features characteristic of hemangiosarcoma (HSA), including irregular vascular channels lined by a plump spindle cell population.

Pseudoangiomatous squamous cell carcinoma in the oral cavity of a dog.

An 8-year-old, spayed, female Labrador Retriever mixed-breed dog was presented to the Cornell University Hospital for Animals with an invasive oral mass involving the upper left fourth premolar and first molar teeth. Initial biopsy results suggested a poorly differentiated squamous cell carcinoma, whereas further histologic examination of the surgically removed mass revealed a hemangiosarcoma-like mass composed of numerous vascular clefts and variable numbers of keratinizing epithelial cells. Histologic and immunohistochemical characteristics were compatible with pseudoangiomatous squamous cell carcinoma, a well-recognized human variant of acanthomatous squamous cell carcinoma.