Assessing Pathologic Response in Resected Lung Cancers: Current Standards, Proposal for a Novel Pathologic Response Calculator Tool, and Challenges in Practice.

The efficacy of neoadjuvant treatment for NSCLC can be pathologically assessed in resected tissue. Major pathologic response (MPR) and pathologic complete response (pCR), defined as less than or equal to 10% and 0% viable tumor cells, respectively, are increasingly being used in NSCLC clinical trials to establish them as surrogate end points for efficacy to shorten time to outcome. Nevertheless, sampling and MPR calculation methods vary between studies. The International Association for the Study of Lung Cancer recently published detailed recommendations for pathologic assessment of NSCLC after neoadjuvant treatment, with methodology being critical. To increase methodological rigor further, we developed a novel MPR calculator tool (MPRCT) for standardized, comprehensive collection of percentages of viable tumor, necrosis, and stroma in the tumor bed. In addition, tumor width and length in the tumor bed are measured and unweighted and weighted MPR averages are calculated, the latter to account for the varying proportions of tumor beds on slides. We propose sampling the entire visible tumor bed for tumors having pCR regardless of size, 100% of tumors less than or equal to 3 cm in diameter, and at least 50% of tumors more than 3 cm. We describe the uses of this tool, including potential formal analyses of MPRCT data to determine the optimum sampling strategy that balances sensitivity against excessive use of resources. Solutions to challenging scenarios in pathologic assessment are proposed. This MPRCT will facilitate standardized, systematic, comprehensive collection of pathologic response data with a standardized methodology to validate studies designed to establish MPR and pCR as surrogate end points of neoadjuvant treatment efficacy.

Histopathologic Assessment of Suspected Idiopathic Pulmonary Fibrosis: Where We Are and Where We Need to Go.

CONTEXT.­: Accurate diagnosis of idiopathic pulmonary fibrosis (IPF) requires multidisciplinary diagnosis that includes clinical, radiologic, and often pathologic assessment. In 2018, the American Thoracic Society, European Respiratory Society, Japanese Respiratory Society, and the Latin American Thoracic Society (ATS/ERS/JRS/ALAT) and the Fleischner Society each published guidelines for the diagnosis of IPF, which include criteria for 4 categories of confidence of a histologic usual interstitial pneumonia (UIP) pattern. OBJECTIVE.­: To (1) identify the role of the guidelines in pathologic assessment of UIP; (2) analyze the 4 guideline categories, including potential areas of difficulty; and (3) determine steps the Pulmonary Pathology Society and the greater pulmonary pathology community can take to improve current guideline criteria and histopathologic diagnosis of interstitial lung disease. DATA SOURCES.­: Data were derived from the guidelines, published literature, and clinical experience. CONCLUSIONS.­: Both guidelines provide pathologists with a tool to relay to the clinician the likelihood that a biopsy represents UIP, and serve as an adjunct, not a replacement, for traditional histologic diagnosis. There are multiple challenges with implementing the guidelines, including (1) lack of clarity on the quantity and quality of histologic findings required, (2) lack of recognition that histologic features cannot be assessed independently, and (3) lack of guidance on how pathologists should incorporate clinical and radiographic information. Current criteria for "probable UIP" and "indeterminate for UIP" hinder accurate reflection of the likelihood of IPF. These challenges highlight the need for further morphologic-based investigations in the field of pulmonary pathology.

Diagnostic Approach to Advanced Fibrotic Interstitial Lung Disease: Bringing Together Clinical, Radiologic, and Histologic Clues.

CONTEXT: - Idiopathic pulmonary fibrosis (IPF) is a distinctive clinicopathologic entity and the most common form of progressive diffuse lung scarring in older adults. Idiopathic pulmonary fibrosis manifests histopathologically as the usual interstitial pneumonia pattern. The usual interstitial pneumonia pattern is distinguished by geographically and temporally heterogeneous fibrosis that is peripherally accentuated, often with honeycombing and traction bronchiectasis. Idiopathic pulmonary fibrosis is not the only disease that leads to end-stage lung fibrosis, however, and several other entities may also cause advanced fibrosis. Surgical lung biopsies often present a diagnostic dilemma when they show clear evidence of advanced fibrosis, but the clinical, imaging, and/or histopathologic subcharacteristics suggest something other than IPF. OBJECTIVE: - To address this dilemma, we review several other fibrotic lung diseases, including connective tissue disease-associated interstitial lung disease, chronic hypersensitivity pneumonitis, advanced pulmonary Langerhans cell histiocytosis, end-stage pulmonary sarcoidosis, Erdheim-Chester disease, Hermansky-Pudlak syndrome, and others, detailing their clinical, radiologic, and histopathologic attributes and emphasizing similarities to and differences from IPF. DATA SOURCES: - Data sources comprised published peer-reviewed literature and personal experience of the authors. CONCLUSIONS: - Often, clues in the lung biopsy may offer the first suggestion of a fibrotic lung disease other than IPF, and accurate classification is important for prognosis, treatment, and the development of future therapies.

A Case of Simultaneous Benign Metastasizing Leiomyomas and Disseminated Peritoneal Leiomyomatosis Following Endoscopic Power Morcellation for Uterine Disease.

Extrauterine spread of leiomyomas is rare and most commonly occurs in the lungs. We present a case of simultaneous metastatic leiomyomatosis to the lungs and peritoneal cavity following laparoscopic myomectomy with power morcellation. The patient presented to our institution for further management where she underwent a robotically assisted hysterectomy with bilateral salpingo-oophorectomy. Leiomyomatous implants measuring up to 2.4 cm were resected from bowel mesentery and bladder peritoneum. Subsequent serial computed tomography imaging confirmed stable pulmonary nodules without new intraperitoneal lesions. Increasing number of cases involving extrauterine spread of leiomyomas has been reported with the introduction of power morcellation. The exact pathogenesis is unknown but is likely multifactorial. We emphasize that although the incidence of spread of benign disease is low, it is important to recognize this phenomenon as we will likely continue to encounter similar cases in the coming years.

Serious Pulmonary Toxicity Secondary to Novel Hepatitis C Antiviral Therapy in a Liver Transplant Recipient.

Historically, the treatment of hepatitis C virus infection has been difficult, but therapeutic options have improved markedly recently because of the development of novel antiviral therapies. These therapies have been well tolerated. We describe a patient who was receiving such therapy and had development of temporally related and histologically confirmed severe pulmonary toxicity. Pulmonary toxicity should be considered a potential serious complication of novel antiviral therapy for hepatitis C virus infection.

An official European Respiratory Society/American Thoracic Society research statement: interstitial pneumonia with autoimmune features.

Many patients with an idiopathic interstitial pneumonia (IIP) have clinical features that suggest an underlying autoimmune process but do not meet established criteria for a connective tissue disease (CTD). Researchers have proposed differing criteria and terms to describe these patients, and lack of consensus over nomenclature and classification limits the ability to conduct prospective studies of a uniform cohort.The "European Respiratory Society/American Thoracic Society Task Force on Undifferentiated Forms of Connective Tissue Disease-associated Interstitial Lung Disease" was formed to create consensus regarding the nomenclature and classification criteria for patients with IIP and features of autoimmunity.The task force proposes the term "interstitial pneumonia with autoimmune features" (IPAF) and offers classification criteria organised around the presence of a combination of features from three domains: a clinical domain consisting of specific extra-thoracic features, a serologic domain consisting of specific autoantibodies, and a morphologic domain consisting of specific chest imaging, histopathologic or pulmonary physiologic features.A designation of IPAF should be used to identify individuals with IIP and features suggestive of, but not definitive for, a CTD. With IPAF, a sound platform has been provided from which to launch the requisite future research investigations of a more uniform cohort.

Pleuroparenchymal fibroelastosis: a rare interstitial lung disease.

Pleuroparenchymal fibroelastosis (PPFE) is a newly described form of interstitial lung disease that originates in the upper lung zones and typically progresses to involve the entire lung. The disease may be idiopathic but is often associated with other pre- or coexisting conditions. Pneumothorax is a common complication and can occur at presentation or at other times during the course of the disease. Pathologically, interstitial fibrosis takes the form of a dense consolidation with some preservation of alveolar septal outlines and demonstrates a distinctly abrupt interface with residual normal lung. Unrecognized cases of PPFE may be incorrectly diagnosed as sarcoidosis, atypical idiopathic pulmonary fibrosis, or other unclassifiable interstitial pneumonias.

Airway-centered interstitial fibrosis: etiology, clinical findings and prognosis.

BACKGROUND: Airway-centered Interstitial Fibrosis (ACIF) is a common pathologic pattern observed in our practice. OBJECTIVES: The objectives of this study are to describe the causes associated with ACIF in a large sample of patients and its effect on survival. METHODS: A retrospective study in three centers of interstitial lung disease in São Paulo, between January of 1995 and December of 2012. The surgical lung biopsy specimens were reviewed by three pathologists. The clinical, functional and tomographic findings were analyzed by a standardized protocol. RESULTS: There were 68 cases of ACIF, most of them women. The mean age was 57 ± 12 yr. Dyspnea, cough, restrictive pattern at spirometry and oxygen desaturation at exercise were common. A reticular pattern with peribronchovascular infiltrates was found in 79% of the cases. The etiologies of ACIF were hypersensitivity pneumonitis in 29 (42.6%), gastroesophageal reflux disease in 17 (25.0%), collagen vascular disease in 4 (5.9%), a combination of them in 15 cases and idiopathic in 3 (4.4%). The median survival was 116 months (95% CI = 58.5 - 173.5). Lower values of oxygen saturation at rest, presence of cough and some histological findings--organizing tissue in the airways, fibroblastic foci and microscopic honeycombing--were predictors of worse survival. CONCLUSIONS: ACIF is an interstitial lung disease with a better survival when compared with IPF. The main etiologies are HP and GERD. The oxygen saturation at rest, the presence of cough and some histological findings are predictors of survival.

Histopathology of the idiopathic interstitial pneumonias (IIP): A review.

The 2013 American Thoracic Society/European Respiratory Society consensus classification update of the idiopathic interstitial pneumonias (IIP) included several important modifications to the organization and spectrum of the diseases that were proposed in an earlier multidisciplinary consensus document in 2002. The histopathology of the now 'major' and 'rare' IIP is presented here with exposition of the newly included entity of a distinctive upper lobe fibrotic lung disease referred to as idiopathic pleuroparenchymal fibroelastosis. The 'rare histological patterns' of acute fibrinous and organizing pneumonia and bronchiolocentric patterns of interstitial pneumonia are illustrated and discussed.

Pulmonary fibrosis in dyskeratosis congenita: report of 2 cases.

Dyskeratosis congenita (DC) is a disorder of poor telomere maintenance and is related to 1 or more mutations that involve the vertebrate telomerase RNA component. Most affected patients develop mucocutaneous manifestations and cytopenias in the peripheral blood between 5 and 15 years of age. DC patients may also develop pulmonary complications including fibrotic interstitial lung disease and pulmonary vascular abnormalities. The radiologic and pathologic features of pulmonary fibrosis associated with DC are poorly defined. Herein, we report 2 new DC cases and suggest that the radiologic and histopathologic findings may resemble usual interstitial pneumonia but may not neatly fit into the current classification of interstitial lung disease.

Lung tumors masquerading as desquamative interstitial pneumonia (DIP): report of 7 cases and review of the literature.

Malignant tumors in the lung (both primary and metastatic) rarely may be associated with markedly discohesive tumor cells, resulting in airspace filling reminiscent of "desquamative interstitial pneumonia" (DIP) on histopathology evaluation. A peculiar aspect of this growth pattern is the relatively bland appearance of the tumor cells, in many cases simulating benign alveolar macrophages at scanning magnification. We searched the Charles Carrington Memorial consultation files in the Department of Laboratory Medicine and Pathology at Mayo Clinic Arizona for instances of malignant tumors in lung simulating DIP, from 1992 to 2011. We identified 7 cases involving transbronchial biopsies, needle core samples, or resected lung specimens. Clinical, histopathologic, and immunohistochemical analyses of these 7 patients were performed, including detailed morphometric analysis of the individual tumor cells using calibrated measurement tools on digital images. We compared the results with those of a control group of 4 patients with benign DIP-macrophage reactions in smoking-related lung disease. The study group comprised 5 male and 2 female patients, 48 to 86 years in age (median: 67 y). The radiologic findings included lobar consolidation, localized ground-glass opacities, and 1 or more nodules. None of the patients had typical bilateral infiltrates of DIP. Microscopically, the lung parenchyma was dominated by the presence of prominent tumor cells filling alveolar spaces. Four patients had primary lung carcinoma (adenocarcinoma), whereas 3 had metastases from other sites, including a melanoma. Immunohistochemical staining studies were performed on 6 of 7 cases to establish the diagnosis. Nuclear diameter, cytoplasmic diameter, and nuclear/cytoplasmic (N/C) ratios in patient and control groups were compared using the Wilcoxon rank sum test. No significant difference in the diameters of nucleus and cytoplasm between cases and control groups (P=0.3447 and 0.7055, respectively) was seen, and only a marginally significant difference in N/C ratios (P=0.0890) was seen. A more complex analysis, generalized estimating equation analysis, showed a significant difference in N/C ratio between the 2 groups (P=0.0278). A "DIP-growth pattern" of malignant tumors in the lung is presented. Although the N/C ratio differences approached statistical significance when compared with controls, the key to diagnosis is the recognition of the malignant cytology of the tumor nuclei. Immunohistochemical studies (keratin or other markers) are helpful in establishing an accurate diagnosis in this setting.

Histopathologic, immunophenotypic and cytogenetic features of pulmonary mucoepidermoid carcinoma.

Pulmonary mucoepidermoid carcinoma is an uncommon but distinctive manifestation of mucoepidermoid carcinoma. Pulmonary mucoepidermoid carcinoma occurs in adults and children and can cause diagnostic problems, especially in small biopsies. Few studies have characterized the histologic and immunophenotypic features of pulmonary mucoepidermoid carcinoma. t(11;19)(q21;p13) is considered disease-defining for mucoepidermoid carcinoma; its significance in pulmonary mucoepidermoid carcinoma warrants further study. Forty three pulmonary mucoepidermoid carcinomas were re-reviewed and graded according to the Brandwein grading system for mucoepidermoid carcinoma. Four cases were excluded because of a split opinion between pathology report and re-review. These cases were negative for MAML2 rearrangement by FISH. TTF-1, napsin A, p40 and p63 immunostains were scored: 0 (negative), 1 (1-25% tumor cells), 2 (26-50%), 3 (51-75%) or 4 (>75%). FISH to detect MAML2 rearrangement used a MAML2-11q21 break-apart probe. Thirty nine pulmonary mucoepidermoid carcinoma (4 low, 30 intermediate, 5 high grade) contained mucous, epidermoid and intermediate cells and lacked keratinization and in situ carcinoma of the overlying epithelium. All cases with available gross description (n=22) had a central/endo- or peribronchial location. All 25 cases tested for immunohistochemistry were positive (scores 1-4) for p63; 23 also expressed p40. In six cases, the p63 score was higher than p40. TTF-1 and napsin were uniformly negative in all 25 cases. MAML2 rearrangement was identified by FISH in each of the 24 cases tested (3 low, 19 intermediate, 2 high grade). Clinical history was available in 29 patients (15 men) (median age, 48 years) with follow-up in 24 (median, 8.4 years). Five patients died of unrelated causes; one developed metastatic pulmonary mucoepidermoid carcinoma. In conclusion, features helpful in distinguishing pulmonary mucoepidermoid carcinoma from other lung cancers include its central/endo- or peribronchial location together with the presence of mucous cells, p63 expression, lack of keratinization and MAML2 rearrangement. TTF-1 and napsin are typically not expressed.

Diagnosis of idiopathic pulmonary fibrosis with high-resolution CT in patients with little or no radiological evidence of honeycombing: secondary analysis of a randomised, controlled trial.

BACKGROUND: Present guidelines for the diagnosis of idiopathic pulmonary fibrosis require histological confirmation of surgical lung biopsy samples when high-resolution CT images are not definitive for usual interstitial pneumonia. We aimed to assess the predictive value of high-resolution CT in a cohort of patients with suspected idiopathic pulmonary fibrosis from a previous randomised trial. METHODS: ARTEMIS-IPF was a randomised, double-blind, placebo-controlled, multicentre, phase 3 trial of ambrisentan for adults aged 40-80 years with well-defined idiopathic pulmonary fibrosis and 5% or less honeycombing on high-resolution CT. In December, 2010, an interim analysis showed lack of efficacy and the trial was stopped. In the present follow-on analysis, we assessed patients who were screened for ARTEMIS-IPF who underwent high-resolution CT as part of screening and surgical lung biopsy as part of standard clinical care. A radiologist and a pathologist from a central panel independently assessed anonymised CT scans and biopsy samples. We calculated the positive and negative predictive value of high-resolution CT (classified as usual interstitial pneumonia, possible usual interstitial pneumonia, and inconsistent with usual interstitial pneumonia) for confirmation of histological patterns of usual interstitial pneumonia. This study is registered with ClinicalTrials.gov, number NCT00768300. FINDINGS: 315 (29%) of 1087 consecutively screened patients in ARTEMIS-IPF had both high-resolution CT and surgical lung biopsy samples. 108 of 111 patients who met high-resolution CT criteria for usual interstitial pneumonia had histologically confirmed usual interstitial pneumonia (positive predictive value 97·3%, 95% CI 92·3-99·4), as did 79 of 84 patients who met high-resolution CT criteria for possible usual interstitial pneumonia (94·0%, 86·7-98·0). 22 of 120 patients had an inconsistent high-resolution CT pattern for usual interstitial pneumonia that was histologically confirmed as not or possible usual interstitial pneumonia (negative predictive value 18·3%, 95% CI 11·9-26·4). INTERPRETATION: In the appropriate clinical setting, for patients with possible usual interstitial pneumonia pattern on high resolution CT, surgical lung biopsy sampling might not be necessary to reach a diagnosis of idiopathic pulmonary fibrosis if high-resolution CT scans are assessed by experts at regional sites familiar with patterns of usual interstitial pneumonia and management of idiopathic interstitial pneumonia. FUNDING: Gilead Sciences.

Approach to lung biopsies from patients with pneumothorax.

CONTEXT: Patients with pneumothorax occasionally require limited lung resections to control persistent air leaks. In some patients, especially smokers, histopathologic findings suggest that a ruptured bulla or bleb caused the pneumothorax. Other patients only exhibit histopathologic changes related to the physical trauma of acute, and likely occult recurrent, peripheral lung injury in the setting of "spontaneous," or idiopathic, lung rupture. Sometimes, pneumothorax occurs secondary to an underlying localized or diffuse parenchymal lung disease. A comprehensive description of the morphologic findings that may be seen in these specimens will help the surgical pathologist distinguish patients with more common and indolent occurrences of pneumothorax from those requiring additional workup or treatment. OBJECTIVE: To develop a diagnostic approach for surgical pathologists encountering lung specimens obtained in the context of pneumothorax repair. DATA SOURCES: Literature review and consultation experience of the authors. CONCLUSIONS: Two general categories of histopathologic changes can be identified: (1) nonspecific changes, reflecting the lung's acute and chronic response to localized injury, and (2) changes suggesting an underlying lung disease that may have played an etiologic role in the development of pneumothorax. The latter changes are important to recognize because they may require additional workup or treatment of clinically occult lung disease. Difficulty arises when nonspecific histopathologic changes overlap with those of an underlying lung disease. Awareness of these diagnostic challenges and pitfalls, together with clinicoradiographic correlation, is essential in these situations and will help guide the surgical pathologist toward an accurate diagnosis and the appropriate management of clinically occult disease.

EIF2AK4 mutations in pulmonary capillary hemangiomatosis.

BACKGROUND: Pulmonary capillary hemangiomatosis (PCH) is a rare disease of capillary proliferation of unknown cause and with a high mortality. Families with multiple affected individuals with PCH suggest a heritable cause although the genetic etiology remains unknown. METHODS: We used exome sequencing to identify a candidate gene for PCH in a family with two affected brothers. We then screened 11 unrelated patients with familial (n = 1) or sporadic (n = 10) PCH for mutations. RESULTS: Using exome sequencing, we identified compound mutations in eukaryotic translation initiation factor 2 α kinase 4 (EIF2AK4) (formerly known as GCN2) in both affected brothers. Both parents and an unaffected sister were heterozygous carriers. In addition, we identified two EIF2AK4 mutations in each of two of 10 unrelated individuals with sporadic PCH. EIF2AK4 belongs to a family of kinases that regulate angiogenesis in response to cellular stress. CONCLUSIONS: Mutations in EIF2AK4 are likely to cause autosomal-recessive PCH in familial and some nonfamilial cases.

Diffuse intrapulmonary malignant mesothelioma masquerading as interstitial lung disease: a distinctive variant of mesothelioma.

Malignant mesothelioma typically encases lungs as a thick rind, while relatively sparing lung parenchyma. We describe an unusual presentation of mesothelioma characterized by diffuse intrapulmonary growth, with absent or inconspicuous pleural involvement, clinically simulating interstitial lung disease (ILD). We identified 5 patients (median age 56 y, all men) with diffuse intrapulmonary malignant mesothelioma in our pathology consultation practice from 2009 to 2012. Clinical history, imaging, and pathology materials were reviewed. Symptoms included chronic dyspnea (4 cases), cough (3), and acute dyspnea with bilateral pneumothorax (1). Chest imaging showed irregular opacities (5), reticulation (4), pleural effusions (2), and subpleural nodular densities (1), without radiologic evidence of pleural disease or masses. A clinicoradiologic diagnosis of ILD was made in all cases, and wedge biopsies were performed. Histologic evaluation revealed a neoplastic proliferation of bland epithelioid or spindled cells, showing various growth patterns simulating silicotic nodules, desquamative interstitial pneumonia, organizing pneumonia, and Langerhans cell histiocytosis. Some areas mimicked adenocarcinoma, with lepidic, acinar, micropapillary, and solid patterns. Initial diagnoses by referring pathologists included reactive changes (1), hypersensitivity pneumonitis versus drug reaction (1), desquamative interstitial pneumonia versus neoplasm (1), and mesothelioma (2). Microscopic pleural involvement was identified in 4 cases. Immunohistochemistry confirmed the characteristic immunophenotype of mesothelioma in all cases. Median survival of 3 patients treated with chemotherapy was 28 months. Two patients received no therapy and survived 3 and 4 weeks, respectively. "Diffuse intrapulmonary malignant mesothelioma" is a rare variant with a distinctive presentation that clinically mimics ILD. Recognition is essential to avoid misdiagnosis.

UIP diagnosed at surgical lung biopsy, 2000-2009: HRCT patterns and proposed classification system.

OBJECTIVE: High resolution CT (HRCT) is diagnostic of usual interstitial pneumonia (UIP) if honeycombing is present. However, biopsy-proven UIP also occurs in patients without honeycombing. Identification of specific HRCT patterns may enable specific diagnosis and allow more patients to enter clinical trials. Pattern may also predict prognosis. We sought to identify specific HRCT patterns in patients with biopsy-proven UIP (2000-2009) and to assess outcomes and serial change in pattern. MATERIALS AND METHODS: We reviewed the HRCT findings in 44 patients with biopsy-proven UIP and identified four distinct patterns: classic UIP (cUIP) with honeycombing, fibrosis without honeycombing (FnoH), minimal fibrosis (Fmin), and ground-glass present (GGOp). We reviewed electronic medical records for outcome information and serial HRCT examinations when available. RESULTS: The extent of fibrosis varied between patterns; findings were always heterogeneous in the cUIP and FnoH patterns. Some Fmin patients had a more homogeneous appearance. The lower lobes were predominantly affected, but upper lobe abnormalities were always present. Mortality from respiratory failure and acute exacerbations occurred regardless of pattern. Serial progression from Fmin to FnoH to cUIP occurred, although in a variable manner. Some individuals had an acute illness (GGOp) as the initial manifestation of UIP. CONCLUSION: The FnoH pattern may be diagnostic of UIP in the proper clinical setting; heterogeneity of HRCT appearance is critical and has not been previously emphasized. Grouping of patients on the basis of pattern may allow more accurate assessment of treatment effects. Further validation and study of these HRCT patterns is warranted. Histologic UIP predicts clinical course.

Sarcoidal granulomas in cytological specimens from intrathoracic adenopathy: morphologic characteristics and radiographic correlations.

BACKGROUND: Clinical experience and literature data suggest that the ability of pathologists to identify granulomas in cytological specimens from intrathoracic lymphadenopathy varies considerably and may negatively influence the yield of transbronchial needle aspiration (TBNA), both conventional and ultrasound-guided (EBUS-TBNA). OBJECTIVES: To describe the cytomorphology of sarcoidal granulomas on TBNA cytology specimens and to analyze the presence of associations between the cytological characteristics of granulomas and the radiographic stage of sarcoidosis. METHODS: TBNA cytological specimens from 123 sarcoidosis patients and 14 tuberculosis patients (control population) were reviewed independently by two pathologists blinded to the clinical-radiological details. RESULTS: Sarcoidal granulomas were small [median (IQR) largest diameter: 0.478 (0.318-0.701) mm] and well-formed, round or elliptical in shape, and almost invariably had a regular contour. Background elements lacked necrotic debris or exudate. The density [median (IQR) number of granulomas per slide: 6.85 (3.66-11) vs. 5.25 (2.5-8), p = 0.073] and size [median (IQR) largest diameter: 0.51 (0.319-0.733) vs. 0.398 (0.318-0.522), p = 0.071] tended to be larger in stage I than in stage II sarcoidosis. A necrotic background was common in the tuberculosis cohort studied (79 vs. 0%, p < 0.0001). CONCLUSIONS: Granulomas can be reliably identified on TBNA cytological material once their characteristic cytomorphology is delineated. A higher density of granulomas in lymphadenopathy of stage I sarcoidosis patients could partly explain the higher success rate constantly obtained by TBNA and EBUS-TBNA in this stage of the disease. A necrotic background suggests a tubercular etiology of the granulomas over a sarcoidal one, in the appropriate clinical setting.

Validation of interobserver agreement in lung cancer assessment: hematoxylin-eosin diagnostic reproducibility for non-small cell lung cancer: the 2004 World Health Organization classification and therapeutically relevant subsets.

CONTEXT: Precise subtype diagnosis of non-small cell lung carcinoma is increasingly relevant, based on the availability of subtype-specific therapies, such as bevacizumab and pemetrexed, and based on the subtype-specific prevalence of activating epidermal growth factor receptor mutations. OBJECTIVES: To establish a baseline measure of interobserver reproducibility for non-small cell lung carcinoma diagnoses with hematoxylin-eosin for the current 2004 World Health Organization classification, to estimate interobserver reproducibility for the therapeutically relevant squamous/nonsquamous subsets, and to examine characteristics that improve interobserver reproducibility. DESIGN: Primary, resected lung cancer specimens were converted to digital (virtual) slides. Based on a single hematoxylin-eosin virtual slide, pathologists were asked to assign a diagnosis using the 2004 World Health Organization classification. Kappa statistics were calculated for each pathologist-pair for each slide and were summarized by classification scheme, pulmonary pathology expertise, diagnostic confidence, and neoplastic grade. RESULTS: The 12 pulmonary pathology experts and the 12 community pathologists each independently diagnosed 48 to 96 single hematoxylin-eosin digital slides derived from 96 cases of non-small cell lung carcinoma resection. Overall agreement improved with simplification from the comprehensive 44 World Health Organization diagnoses (κ  =  0.25) to their 10 major header subtypes (κ  =  0.48) and improved again with simplification into the therapeutically relevant squamous/nonsquamous dichotomy (κ  =  0.55). Multivariate analysis showed that higher diagnostic agreement was associated with better differentiation, better slide quality, higher diagnostic confidence, similar years of pathology experience, and pulmonary pathology expertise. CONCLUSIONS: These data define the baseline diagnostic agreement for hematoxylin-eosin diagnosis of non-small cell lung carcinoma, allowing future studies to test for improved diagnostic agreement with reflex ancillary tests.