Renal cell carcinoma is wicked about spreading to the gastrointestinal tract and masquerading as angiosarcoma or as xanthoma. This lesion simply presented as an upper tract eroded mass. #UMiamiPath

The carcinoma associated with this 1.5 cm colonic adenoma is not fooling around - it went into the deepest part of the submucosa and is at the cauterized submucosal (deep) margin. Get your colonoscopy if it's time and you did not! #UMiamiPath

This is a striking example of portal hypertensive colopathy in a patient with cirrhosis. #umiamipath

Gastric fundic gland polyps and a foveolar adenoma from a patient with gastric adenocarcinoma proximal polyposis syndrome (GAPPS), a variant of familial adenomatous polyposis. Because the APC gene is large, the mutation was not detected until 2016. #umiamipath PMID: 27087319

This vascular malformation extended into a patient's joint space, involving synovial tissue. Note the overgrowth of adipose tissue and irregularly shaped blood vessels. #umiamipath

Dr. Garcia is a force of nature!! #UMiamiPath

Russell body carditis. Russell bodies are inclusions of immunoglobulins accumulating in the rough endoplasmic reticulum of overstimulated plasma cells (Mott cells). The PAS staining can raise concern for adenocarcinoma to the unwary! #UMiamiPath

This sample from a laparoscopic procedure to repair a gastric ulcer shows reactive myofibroblasts - immunohistochemistry was not needed, shedding heat not light. The keratin reflects the submesothelial location and the CD117 is from excessive antigen retrieval - #UMiamiPath

A dainty small bowel gastrinoma in a patient with multiple endocrine neoplasia, type 1 (MEN1) resulted in an enormous lymph node metastasis. This phenomenon has probably resulted in at least some reports of primary gastrinoma of lymph node. #UMiamiPath

Hepatic Epstein-Barr virus-associated smooth muscle tumor. This lesion arose in a man with HIV disease and multiple other medical problems. Desmin, CD117, and DOG1 were negative. #umiamipath PMIDs:36965331, 16330945.

This example of low-grade dysplasia in Barrett's esophagus (or gastric cardia) resembles a colorectal tubular adenoma. The gastric cardiac glands and adjoining squamous mucosa indicate the gastroesophageal origin. innovativesciencepress.com

This Lynch-associated gastric carcinoma shows loss of MSH6 in both the pyloric gland adenomatous precursor and the carcinoma in background oxyntic mucosa without gastritis. #UMiamiPath

This image of esophageal varices is courtesy of Dr. Dale Snover. #UMiamiPath

Bread and Butter: It's easy to overlook T4a colorectal carcinoma when mesothelium (indicated) extends up along adipose tissue lobules. In this case, the cancer cells link to the mesothelial cells via inflammation. #umiamipath

Buy early and often at ECP!

Sessile serrated adenoma (polyp, lesion) with high grade dysplasia. The 2019 WHO classification said not to grade conventional dysplasia in these because any histologically apparent dysplasia is on the fast tract to progression but some of us do PMID: 35040174; #UMiamiPath

This leiomyosarcoma has spread to bone from a retroperitoneal primary. #UMiamiPath

A stunning example of a giant condyloma; this one was probably human papilloma virus (HPV) 6 driven - in situ hybridization using an HPV6/11 cocktail was reactive. #umiamipath

This classic example of ossifying fibromyxoid tumor displays a shell of bone and uniform cytologic features; it's an H&E diagnosis. Without classic features, detecting PFH1 rearrangements (several partner genes reported) is useful. #UMiamiPath PMIDs: PMID: 2476942, 23887158.

Claudin 18.2 immunohistochemistry is new for gastric and esophageal adenocarcinomas. Benign gastric mucosa is the internal positive control. 2+-3+ membrane staining in ≥75% of tumor cells is the cutoff for use of anti-CLDN18.2 (zolbetuximab). #UMiamiPath PMID: 39098518.