Incidence of composite intestinal adenoma-microcarcinoid in 158 surgically resected polyps and its association with squamous morule.

Composite intestinal adenoma-microcarcinoid (CIAM) is a rare colorectal lesion consisting of adenoma and small well-differentiated neuroendocrine cell clusters at its base. Its incidence is unknown. Benign squamous morule may demonstrate a neuroendocrine phenotype by immunohistochemistry. We investigated the incidence and clinicopathologic features of CIAM in endoscopically unresectable, surgically removed colorectal adenomas and evaluated its association with squamous morule. Archived pathology materials from 158 surgically resected colorectal adenomas were reviewed. 139 (88%) polyps were entirely submitted for microscopic examination. All lymph nodes were negative for adenocarcinoma and neuroendocrine tumor. CIAM was identified in 6 (3.8%) cases. The microcarcinoid (MC) was distributed over a mean of 5.8 mm (range < 1 to 12 mm), and was multifocal in 5 cases. The MC component was positive for synaptophysin in 6, CK5/6 in 4, and ß-catenin in 3 cases. Two of 6 (33.3%) CIAM showed concurrent squamous morule, compared to 4.0% (6 of 152) of adenomas without MC (p < 0.05). At the end of the mean follow-up of 53 months, 4 were free of disease and one patient with previous history of pulmonary large cell neuroendocrine carcinoma (NEC) had a recurrence of NEC. One patient died of an unrelated disease. The incidence of CIAM in surgically removed colorectal adenomas is 3.8%, with an indolent clinical course. Frequent co-expression of CK5/6 and ß-catenin in MC combined with common co-existence of squamous morule in the same polyp suggests shared pathogenesis of MC in CIAM and squamous morule, likely representing altered Wnt/ß-catenin signaling pathway.

The expression of TTF1, CDX2 and ISL1 in 74 poorly differentiated neuroendocrine carcinomas.

BACKGROUND: The expression profile of immunohistochemical markers of origin in poorly differentiated neuroendocrine carcinoma (PDNEC) is not well studied. MATERIALS AND METHODS: Seventy-four PDNECs from gastroenteropancreatic (GEP) organs and the lung, including 48 large cell NEC (LCNEC) and 26 small cell carcinomas (SmCC), were subject to immunohistochemical staining for CDX2, TTF1 and ISL1. The staining intensity (1 to 3) and percentage of positive tumor cells [0 (negative), 1 (<50%) and 2 (≥50%)] were assessed. The multiplicative index (maximum 6) was calculated and the average total score (aTS) was determined for each primary site and histologic subtype. RESULTS: In the 38 GEP and 36 lung PDNECs, CDX2, TTF1 and ISL1 staining was observed in 71% (aTS 2.8), 16% (aTS 0.4), 63% (aTS 1.9), and 22% (aTS 0.6), 72% (aTS 2.9) and 92% (aTS 3.8), respectively. GEP PDNECs showed a higher aTS for CDX2 and lower aTS for TTF1 and ISL1, compared to that of lung PDNECs (Student's t-test, p < 0.001). SmCC had a higher aTS for TTF1 and ISL1 (p < 0.001) and lower aTS for CDX2 (p < 0.002) than that of LCNEC. CONCLUSIONS: CDX2 and TTF1 demonstrate potential utility in suggesting the primary site of PDNEC. In addition, CDX2 may be useful in supporting the diagnosis of LCNEC in cases with overlapping or borderline morphology. Utility of ISL1 as an adjunctive diagnostic marker of SmCC remains to be studied.

Urothelial Carcinoma: Epidemiology and Imaging-Based Review.

Bladder cancer is the 6th most common malignancy in the United States, with urothelial carcinomas comprising over 95% of cases of bladder cancer, and commands a significant disease burden in Rhode Island. Imaging studies can provide valuable diagnostic information for urothelial carcinomas at initial presentation and are routinely used for noninvasive staging, treatment response monitoring, and post-treatment surveillance. This review aims to discuss and highlight three imaging modalities: ultrasonography, computed tomography, and magnetic resonance imaging, with particular focus on the notable features and appearance of urothelial carcinoma on each modality and their relative utility throughout the disease course. A general overview of disease epidemiology and treatment practices is also provided.

Increased Cytoplasmic Yes-associated Protein (YAP) Expression in Mismatch Repair Protein-Proficient Colorectal Cancer With High-grade Tumor Budding and Reduced Autophagy Activity.

Yes-associated protein (YAP) is a transcriptional coactivator regulated by autophagy that stimulates colorectal cancer (CRC) progression through activation of epithelial-mesenchymal transition (EMT), represented by tumor budding. The associations between these components in CRC are unknown. Archived surgically resected CRCs with known mismatch repair protein (MMR) status were retrieved (n=81; 2010 to 2016). Electronic medical records were reviewed for clinicopathologic variables including pathologic TNM stage and clinical stage. Tumor budding was graded according to consensus guidelines. Cytoplasmic and nuclear YAP and p62 (autophagy substrate) immunoreactivity were semiquantitatively scored within tumor samples. The Student t test, Fisher exact test, χ2 test, and Spearman correlation coefficient were performed with P<0.05 as a significance level. MMR proficiency (MMR-P) status correlated with high-grade tumor budding. The extent of cytoplasmic YAP staining and pathologic N stage was associated with tumor budding in multivariate analysis. Cytoplasmic YAP expression correlated with higher cytoplasmic p62 expression, suggesting an inverse correlation between autophagy activation and cytoplasmic YAP expression. Nuclear YAP expression correlated with pathologic N stage and clinical stage. A correlation between MMR-P status and tumor budding, combined with correlations between cytoplasmic YAP, tumor budding and p62 raise the possibility of 2 distinct neoplastic pathways concerning autophagy and YAP; one displaying relative activation of YAP and EMT, being commonly observed in MMR-P, and another with less active YAP and EMT, but active autophagy, being commonly seen in MMR-deficient CRC. Nuclear YAP staining could be useful in prognostication.

Histologic Lesions of Porto-Sinusoidal Vascular Disease Following Phlebotomy in Hemochromatosis.

BACKGROUND: Phlebotomy induces regression of liver fibrosis in genetic hemochromatosis. We assessed the histologic changes in pre-phlebotomy and post-phlebotomy liver biopsies from patients with HFE mutation as a model to study regression of fibrosis. We aimed to show that phlebotomy-induced histologic lesions overlap with porto-sinusoidal vascular disease (PSVD, also known as idiopathic non-cirrhotic portal hypertension), histologically. METHODS: A total of 51 biopsies (22 pre-phlebotomy and 29 post-phlebotomy) were reviewed, and three variables were studied: iron index indicative of the amount of accumulated iron (range 0 to 18), the combined score of vascular changes reflecting the presence of histological lesions that are described in PSVD (range 0 to 9) and the high-grade shunt vessel by calculating the proportion of portal tracts with shunt vessels, with a cutoff of 50%. Two-tailed Student's t-test and Fisher's exact test were performed to compare the means of two variables and frequencies of the histologic lesions in two groups, respectively. A P-value < 0.05 was considered statistically significant. RESULTS: The iron index was higher in the pre-phlebotomy compared to post-phlebotomy group (P = 0.01). Compared to the pre-phlebotomy group, the combined score was higher in the post-phlebotomy group when the cases of advanced fibrosis were excluded (P = 0.023) and remained higher when patients with risk factors for PSVD were further excluded (P = 0.034). The high-grade shunt vessel tended to be more common in the post-phlebotomy group when advanced fibrosis was excluded; however, the statistical significance was marginal (P = 0.056). CONCLUSIONS: Phlebotomy reduces hepatic iron load and induces histologic lesions of PSVD in patients with HFE mutation. Our data support a postulation that some of the histologic lesions of PSVD represent vascular remodeling following a regression of fibrosis and may not be reflective of risk factors or etiopathogenesis of PSVD. Regressed fibrosis and PSVD may not be reliably distinguished in a limited sample, therefore warranting cautious interpretation in the right clinical context.