Results of morphological screening for Lynch syndrome during the period 2013-2016.

The introduction of a screening system for Lynch syndrome in pathology laboratories in Plzen yielded 24 diagnoses of Lynch syndrome during the period of 2013-2016, 20 of them presenting with colorectal cancer. In 8 of those 24 cases germline mutations of MMR genes, previously not recognized as pathogenic with certainty, were detected. Although the frequency of Lynch syndrome in patients with colorectal cancer was only 0.

Frozen section examination of pancreas, gallbladder, extrahepatic biliary tree, liver, and gastrointestinal tract.

The main indications for intraoperative consultation of gastrointestinal tract, liver, and pancreatobiliary system are to evaluate the resection margin and to make a tissue diagnosis of lesions for which preoperative histology is not aviable for various reasons. Special situations include the evaluation of liver donor biopsies for the presence of steatosis and inflamation, or determination that ganglion cells are present in the bowel wall at the level where the anastomosis will be placed in case of Hirschprung's disease. The most worrisome pitfalls include differentiating pancreatic ductal carcinoma from chronic pancreatitis, distinguishing biliary tree and gallbladder carcinoma from reactive changes caused by inflammation, and recognizing the presence of diffuse adenocarcinoma at the resection margin of the esophagus and stomach.

Triple marker composed of p16, CD56, and TTF1 shows higher sensitivity than INSM1 for diagnosis of pulmonary small cell carcinoma: proposal for a rational immunohistochemical algorithm for diagnosis of small cell carcinoma in small biopsy and cytology specimens.

Pulmonary small cell carcinoma (SCLC) can be usually diagnosed based on the morphological evaluation of routine histological or cytological preparations. However, immunohistochemistry may be also necessary in problematic cases. Insulinoma-associated 1 (INSM1) has recently been reported as a highly sensitive and specific marker that displays positivity in ~90%-100% of poorly differentiated pulmonary neuroendocrine tumors.

P16 is a useful supplemental diagnostic marker of pulmonary small cell carcinoma in small biopsies and cytology specimens.

Pulmonary small cell carcinoma (SCLC) is usually diagnosed in small biopsy or cytological specimens based on cytomorphology; however in ambiguous cases diagnosis requires additional support by immunohistochemistry. While TP53 and RB1 alterations with secondary overexpression of p16 are mainstay events in SCLC pathogenesis, diagnostic value of p16-positivity in the diagnosis of SCLC has not yet been fully investigated. We examined the expression of p16, CD56, synaptophysin (SYP), chromogranin A and thyroid transcription factor-1 (TTF1) in a series of pulmonary and extrapulmonary small cell carcinomas, pulmonary carcinoids and non-small cell lung carcinomas, and compared diagnostic performance of these markers in the diagnosis of SCLC.

Nonsyndromic Intestinal Lipomas are Probably not Associated With Mutations of PDGFRA.

The purpose of this study was to test the hypothesis that intestinal lipomas occurring in patients devoid of signs of PDGFRA-mutant syndrome might represent sporadic counterparts of familial lipomatous tumors occurring in the spectrum of tumors associated with PDGFRA mutations. PDGFRA-mutant syndrome may manifest with gastrointestinal stromal tumors, Vanek tumors, fibrous tumors, and lipomatous tumors. Until now there has been no molecular genetic study of PDGFRA mutations in intestinal lipomas published in the world literature.