"Infiltrative" Versus "Mass-Forming" Pancreatic Cancer: A New Radiological Classification System for Pancreatic Head Ductal Carcinoma and Its Pathological Correlation.

Purpose: Resectability in localized pancreatic ductal adenocarcinoma (PDAC) is deemed through radiological criteria. Despite initial evaluation classifying tumors as "resectable," they often have ill-defined borders that can result in more extensive cancer than predicted on final pathology analysis. We attempt to categorize these tumors radiologically and define them as "infiltrative" and contrast them to more well-defined or "mass-forming" tumors and assess their correlation with surgical oncological outcomes. We hypothesize that mass-forming lesions will result in fewer positive resection margins. Methods: Patients diagnosed with PDAC of the head of the pancreas and who underwent subsequent curative intent resection between 2016 and 2018 were included. A retrospective chart review of patients was conducted and computed tomography images at the time of diagnosis were reviewed by two radiologists and scored as "mass forming" or "infiltrative" using a newly developed classification system. These classifications were then correlated with margin status. Results: Sixty-eight consecutive pancreatoduodenectomies performed for PDAC from 2016 to 2018 were identified. After screening, 54 patients were eligible for inclusion. Radiologically defined mass-forming lesions had a trend toward a lower rate of positive resection margins (35.7% vs. 50.0%; p = 0.18), specifically the bile duct margin and pancreas margin as well as an overall larger size (4.03 cm vs. 3.25 cm, p = 0.02) compared with infiltrative lesions. Conclusion: We propose a new radiological definition of PDAC into "mass forming" and "infiltrative," a nomenclature that resonates with other tumor sites. Infiltrative lesions trended toward a higher rate of positive resection margins. This classification may help tailor therapy for infiltrative tumors toward a neoadjuvant approach even if they appear resectable.

Myxoma versus myxoid liposarcoma involving the kidneys.

Myxoid lesions of the kidney are rare. We present a case of a 74-year-old man who presented with an 8.5 × 8.0 × 6.0 cm left kidney mass that was grossly confined to the kidney and had a gelatinous cut surface. Histology of the tumor showed bland spindle cells in a myxoid stroma with interspersed thin-walled vessels. The tumor was negative for smooth muscle actin, desmin, CD34 (highlighted vessels), S100, and HMB-45 by immunohistochemistry. There was focal, nonspecific staining of MDM2 and CDK4. The lesion appeared more vascular than would be expected for a classic myxoma and, therefore, fluorescence in situ hybridization was performed for the 12q13 (DDIT3 or CHOP) rearrangement to rule out myxoid liposarcoma and the result was negative for a rearrangement. This case highlights the difficulty of delineating a primary myxoma of the kidney from a well-differentiated myxoid liposarcoma.

Whole Slide Imaging Versus Microscopy for Primary Diagnosis in Surgical Pathology: A Multicenter Blinded Randomized Noninferiority Study of 1992 Cases (Pivotal Study).

Most prior studies of primary diagnosis in surgical pathology using whole slide imaging (WSI) versus microscopy have focused on specific organ systems or included relatively few cases. The objective of this study was to demonstrate that WSI is noninferior to microscopy for primary diagnosis in surgical pathology. A blinded randomized noninferiority study was conducted across the entire range of surgical pathology cases (biopsies and resections, including hematoxylin and eosin, immunohistochemistry, and special stains) from 4 institutions using the original sign-out diagnosis (baseline diagnosis) as the reference standard. Cases were scanned, converted to WSI and randomized. Sixteen pathologists interpreted cases by microscopy or WSI, followed by a wash-out period of ≥4 weeks, after which cases were read by the same observers using the other modality. Major discordances were identified by an adjudication panel, and the differences between major discordance rates for both microscopy (against the reference standard) and WSI (against the reference standard) were calculated. A total of 1992 cases were included, resulting in 15,925 reads. The major discordance rate with the reference standard diagnosis was 4.9% for WSI and 4.6% for microscopy. The difference between major discordance rates for microscopy and WSI was 0.4% (95% confidence interval, -0.30% to 1.01%). The difference in major discordance rates for WSI and microscopy was highest in endocrine pathology (1.8%), neoplastic kidney pathology (1.5%), urinary bladder pathology (1.3%), and gynecologic pathology (1.2%). Detailed analysis of these cases revealed no instances where interpretation by WSI was consistently inaccurate compared with microscopy for multiple observers. We conclude that WSI is noninferior to microscopy for primary diagnosis in surgical pathology, including biopsies and resections stained with hematoxylin and eosin, immunohistochemistry and special stains. This conclusion is valid across a wide variety of organ systems and specimen types.

Low prevalence of H. pylori infection in patients with gastroparesis.

BACKGROUND: The histopathology of the gastric mucosa in patients with gastroparesis, a condition characterized by gastric retention without obstruction, has not been described. AIM: To test the hypothesis that reactive gastropathy is more common in patients with gastroparesis than in subjects with normal gastric motility. METHODS: We compared the prevalence of reactive gastropathy, Helicobacter pylori infection, chronic gastritis, and intestinal metaplasia in patients with and without a clinical diagnosis of gastroparesis extracted from a national database of subjects with gastric biopsies (1/2008-6/2012). RESULTS: There were 3040 patients with gastroparesis (median age 58 years, 67.3% women) and 575,895 controls (median age 57 years, 62.0% women) with no evidence of gastroparesis. Reactive gastropathy was marginally more prevalent in patients with gastroparesis (18.9%) than in controls (17.0%). In contrast, H. pylori gastritis was present in 10.8% of controls, but only in 5.9% patients with gastroparesis (OR 0.52; 95% CI 0.45-0.61). Intestinal metaplasia was also less common in patients with gastroparesis (2.8% versus 3.9%; OR 0.82; 95% CI 0.58-0.89). CONCLUSIONS: The low prevalence of H. pylori infection in gastroparesis could be explained by higher rates of previous eradication, conditions unfavourable to the survival of H. pylori, or a protective effect of mucosal inflammation against the development of motility disorders.