The American journal of surgical pathology
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Am. J. Surg. Pathol. · Oct 2018
Comparative StudyPD-L1 Assays 22C3 and SP263 are Not Interchangeable in Non-Small Cell Lung Cancer When Considering Clinically Relevant Cutoffs: An Interclone Evaluation by Differently Trained Pathologists.
Pembrolizumab is the only programmed cell death 1/programmed death-ligand 1 inhibitor for treatment of patients with non-small cell lung cancer, with a companion diagnostic assay, the 22C3 PharmDx. Although in many studies 22C3 and Ventana's SP263 appear to yield overlapping results, they show discrepancies at clinically relevant cutoffs (1% and 50%). We provide a solid comparison between 22C3 and SP263 assays in a large cohort of non-small cell lung cancer cases taking into account interobserver variability between trained pathologists who are used to either clone in their clinical practice. ⋯ Important differences were also observed, when comparing clone 22C3 and SP263, both run on the Ventana platform. The lowest differences were seen with 22C3 run on both platforms. Assays 22C3 and SP263 show important discrepancies in identifying programmed death-ligand 1-positive cases at clinically relevant cutoffs, with possible underestimation of patients suitable for pembrolizumab therapy.
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Am. J. Surg. Pathol. · May 2018
Comprehensive Assessment of PD-L1 Staining Heterogeneity in Pulmonary Adenocarcinomas Using Tissue Microarrays: Impact of the Architecture Pattern and the Number of Cores.
Checkpoint inhibitors directed against programmed death receptor 1 (PD-1) and its ligand (PD-L1) changed the treatment of advanced lung non-small cell carcinomas. The decision to treat patients is influenced by PD-L1 expression by tumor cells, but evidence indicates that this staining is heterogenous within a tumor. As PD-L1 staining is tested mostly on biopsies, false negative results can occur due to sampling issues. ⋯ Mean staining of PD-L1 was higher in solid (47.9%) and micropapillary (24.2%) patterns and was lower in acinar (14.1%), papillary (3.4%), and lepidic (6.4%) architectures. A significant proportion of patients presented a heterogenous staining for PD-L1. A total of 26.5% of patients negative on 1 core turned out to be positive on another core, which raises the consideration of rebiopsy, in particular when lepidic, acinar, or papillary patterns are observed on a biopsy.
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Am. J. Surg. Pathol. · May 2018
Comparative StudySignificance of T1a and T1b Carcinoma Arising in Mucinous Cystic Neoplasm of Pancreas.
Mucinous cystic neoplasm (MCN) of pancreas is one of the precursor lesions of pancreatic ductal adenocarcinoma. The 5-year disease-specific survival for noninvasive MCNs was 100% and 20% to 60% for those with pancreatic ductal adenocarcinoma arising in a MCN. However, the significance of T1a (≤0.5 cm) and T1b (>0.5 and <1.0 cm) carcinoma arising in MCN as defined by the upcoming American Joint Committee on Cancer, eighth edition is unclear. ⋯ In contrast, 5 of 7 patients who had MCN with advanced invasive carcinoma had recurrence and later died of disease with a median survival of 22.9 months (P<0.001). Our study showed that MCN with T1a and T1b carcinoma had an excellent prognosis similar to MCNs with LGD or HGD after complete tumor sampling for histologic examination. Our results along with the previous studies suggest that close follow-up, rather than aggressive systemic therapy, may be a better approach for these patients.
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Am. J. Surg. Pathol. · May 2018
Analysis of the Histologic Features Associated With Interobserver Variation in Idiopathic Pulmonary Fibrosis.
The histologic manifestation of idiopathic pulmonary fibrosis (IPF) is usual interstitial pneumonia (UIP), which is a good prognostic determinant of survival compared with other histologic interstitial lung disease patterns. According to the current international guidelines, the histologic features of suspected IPF/UIP are divided into 4 categories: UIP, probable UIP, possible UIP, and not UIP pattern. Four pulmonary pathologists who were blinded to clinicoradiologic information reevaluated 50 surgical lung biopsies (83.3%), 6 lung explant (10.0%), and 4 autopsy samples (6.7%) from the FinnishIPF registry (N=60) using the current diagnostic guidelines. ⋯ The observed histologic features displayed no association with radiologic patterns or survival. Definite UIP and honeycombing findings in high-resolution computed tomography correlated with poor prognosis. A high level of interobserver variability was observed between pathologists, even in this well-defined cohort of IPF patients, which highlights the importance of multidisciplinary decision making in IPF diagnostics and stresses the need for a reassessment of the histologic criteria.
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Am. J. Surg. Pathol. · Apr 2018
Histologic Features of Gastrointestinal Tract Biopsies in IgA Vasculitis (Henoch-Schönlein Purpura).
Immunoglobulin A (IgA) vasculitis or Henoch-Schönlein purpura (HSP) typically occurs in the pediatric population, although rare cases also occur in adults. Gastrointestinal (GI) involvement is common. The "classic" histologic finding in IgA vasculitis (HSP) is leukocytoclastic vasculitis (LCV); other histologic features in biopsies of IgA vasculitis (HSP) have only been rarely described. ⋯ In general, vasculitis is not commonly observed in GI biopsies of patients with IgA vasculitis (HSP), and the spectrum of findings includes neutrophilic infiltrate within the small bowel and colon, with the duodenum most commonly affected. While the clinical and histologic findings may mimic early inflammatory bowel disease, the presence of predominant small bowel involvement, especially erosive duodenitis, should raise suspicion for IgA vasculitis (HSP). Biopsies should be obtained before steroid therapy is initiated, if possible.