The American journal of surgical pathology
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Am. J. Surg. Pathol. · Dec 2017
Idiopathic Myointimal Hyperplasia of Mesenteric Veins: An Uncommon Cause of Ischemic Colitis With Distinct Mucosal Features.
Idiopathic myointimal hyperplasia of mesenteric veins causes chronic ischemic mucosal injury with segmental strictures that mimic inflammatory bowel disease and nonocclusive ischemic colitis. It is characterized by myointimal proliferative changes that narrow the lumina of veins combined with ischemic injury and ulcers. Most cases reported to date have been diagnosed following surgical resection. ⋯ Biopsies showed arteriolized capillaries (100%), subendothelial fibrin deposits (86%), fibrin thrombi (43%), and perivascular hyalinization (43%). Fibrin thrombi were observed in only one case each of ischemic colitis and small vessel vasculitis, and none of the other abovementioned features were seen in any of the controls. We conclude that arteriolized capillaries, subendothelial fibrin deposits, and perivascular hyalinization are frequent and specific features that can facilitate recognition of idiopathic myointimal hyperplasia of mesenteric veins in biopsy samples.
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Am. J. Surg. Pathol. · Oct 2017
Pathologic Separation of Chronic Hypersensitivity Pneumonitis From Fibrotic Connective Tissue Disease-associated Interstitial Lung Disease.
Chronic (fibrotic) hypersensitivity pneumonitis (HP) and fibrosing interstitial pneumonias associated with connective tissue disease (CTD-ILD) can be difficult to distinguish in biopsy specimens. To investigate features that might separate these entities, 2 pathologists blinded to the diagnoses reviewed 16 cases of chronic HP and 12 cases of CTD-ILD. Fifteen predefined parameters were examined by morphometric point counting, analysis/cm of lung tissue, or presence/absence. ⋯ Number of fibroblast foci/cm, distribution of fibroblast foci, pattern of fibrosis, presence of giant cells/granulomas, and volume proportion of lymphocytes or eosinophils did not distinguish chronic HP from CTD-ILD. We conclude that no single morphologic measure definitively separates chronic HP from CTD-ILD lung biopsies, but numerous foci of peribronchiolar metaplasia favor HP, while the presence of germinal centers, large numbers of lymphoid aggregates, or a high plasma cell: lymphocyte ratio suggests CTD-ILD. Multidisciplinary discussion is often necessary for accurate classification inthis setting.
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Am. J. Surg. Pathol. · Sep 2017
WNT Pathway Gene Mutations Are Associated With the Presence of Dysplasia in Colorectal Sessile Serrated Adenoma/Polyps.
Sessile serrated adenoma/polyps (SSA/Ps) are believed to be the major precursor of serrated pathway-derived colorectal carcinomas. To better characterize the process of progression from SSA/Ps to carcinomas, we analyzed 46 SSA/Ps with dysplasia and 45 SSA/Ps without dysplasia using targeted next-generation sequencing and immunohistochemistry. Among the WNT pathway genes analyzed, protein-truncating mutations of RNF43, APC, and ZNRF3 were identified in 23 (50%), 4 (9%), and 3 (7%) SSA/Ps with dysplasia, respectively. ⋯ The majority of MLH1-deficient SSA/Ps with dysplasia had RNF43 mutations (86%), most of which were frameshift mutations involving mononucleotide repeats. In contrast, MLH1-retained lesions had less frequent RNF43 mutations with no hot spots (34%), and 4 had APC mutations (13%). These results suggest that WNT pathway gene mutations are involved in the development of dysplasia in SSA/Ps and that MLH1-deficient and MLH1-retained SSA/Ps with dysplasia exhibit distinct mutation profiles of WNT pathway genes.
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Am. J. Surg. Pathol. · Aug 2017
Tumor Spread Through Air Spaces Is an Independent Predictor of Recurrence-free Survival in Patients With Resected Lung Squamous Cell Carcinoma.
Tumor spread through air spaces (STAS) is a newly recognized pattern of invasion in lung adenocarcinoma. However, clinical significance of STAS has not yet been characterized in lung squamous cell carcinoma. In this study, we investigated whether STAS could determine clinical outcome in Japanese patients with lung squamous cell carcinoma. ⋯ On multivariate analysis, STAS was an independent prognostic factor of a worse RFS (hazard ratio=1.61; P=0.023). Patients with STAS had a significantly increased risk of developing locoregional and distant recurrences (P=0.012 and 0.001, respectively). We found that tumor STAS was an independent predictor of RFS in patients with resected lung squamous cell carcinoma, and it was associated with aggressive tumor behavior.
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Am. J. Surg. Pathol. · Jul 2017
Development of a New Outcome Prediction Model in Early-stage Squamous Cell Carcinoma of the Oral Cavity Based on Histopathologic Parameters With Multivariate Analysis: The Aditi-Nuzhat Lymph-node Prediction Score (ANLPS) System.
The aim of this study was to evaluate the histopathologic parameters that predict lymph node metastasis in patients with oral squamous cell carcinoma (OSCC) and to design a new assessment score on the basis of these parameters that could ultimately allow for changes in treatment decisions or aid clinicians in deciding whether there is a need for close follow-up or to perform early lymph node dissection. Histopathologic parameters of 336 cases of OSCC with stage cT1/T2 N0M0 disease were analyzed. The location of the tumor and the type of surgery used for the management of the tumor were recorded for all patients. ⋯ The risk of lymph node metastasis in OSCC is influenced by many histologic parameters that are not routinely analyzed in pathologic reports. These significant independent factors were graded to design a scoring system that permits accurate evaluation of the risk of metastasis with accuracy independent of the traditional TNM system or isolated histologic parameters. The need for neck node dissection can be predicted depending upon the scores obtained.