Granulomatous inflammation-an underestimated cause of false-positive diagnoses in lung fine-needle aspirates: observations from the college of american pathologists nongynecologic cytopathology interlaboratory comparison program

Second opinion for pulmonary and pleural cytology is valuable for patient care

INTRODUCTION

Thoracic cytology can be challenging due to limited procured material or overlapping morphology between benign and malignant entities. In such cases, expert consultation might be sought. This study aimed to characterize all pulmonary and pleural cytology consult cases submitted to our practice and provide recommendations on approaching difficult cases.

MATERIALS AND METHODS

All thoracic (pulmonary and pleural) cytology cases submitted for expert consultation to the University of Michigan (MLabs) from 2013 to mid-2022 were reviewed. Cases where cytology was only part of a hematopathology or surgical pathology consult were excluded. Patient demographics, specimen location, procedure performed, referring diagnosis, and our diagnoses were recorded for each case. Diagnoses were categorized according to the Papanicolaou Society of Cytopathology recommendations for pulmonary and effusion cytology. Discordant diagnoses were stratified as major or minor. Data was analyzed using chi-square analysis and logistic models.

RESULTS

We received 784 thoracic cytology consult cases, including 530 exfoliative samples and 307 fine-needle aspirations. The most common anatomic locations sampled were the bronchial wall (n = 194, 23%), lung nodule (n = 322, 38%), and pleura (n = 296, 35%). 413 cases had a diagnostic discrepancy (48.3%), with 274 (66%) minor and 139 (34%) major discrepancies. By location, pleural effusion specimens had the highest probability of a discrepant diagnosis (P = 0.003). By specimen type, fine-needle aspiration samples were significantly more likely to have a discrepant diagnosis (P = 0.06).

CONCLUSION

Nearly half of the thoracic cytology cases submitted for expert second opinion had diagnostic discrepancies. Consequently, consulting a tertiary medical care center with cytopathology expertise for challenging thoracic cytology diagnoses is beneficial.

Computed tomography-guided cutting needle biopsy for lung nodules: when the biopsy-based benign results are real benign

Background

Computed tomography (CT)-guided cutting needle biopsy (CNB) is an effective diagnostic method for lung nodules (LNs). The false-negative rate of CT-guided lung biopsy is reported to be up to 16%. This study aimed to determine the predictors of true-negative results in LNs with CNB-based benign results.

Methods

From January 2011 to December 2015, 96 patients with CNB-based nonspecific benign results were included in this study as the training group to detect predictors of true-negative results. From January 2016 to December 2018, an additional 57 patients were included as a validation group to test the reliability of the predictors.

Results

In the training group, a total of 96 patients underwent CT-guided CNB for 96 LNs. The CNB-based results were true negatives for 82 LNs and false negatives for 14 LNs. The negative predictive value of the CNB-based benign results was 85.4% (82/96). Univariate and multivariate logistic regression analyses revealed that CNB-based granulomatous inflammation (P = 0.013, hazard ratio = 0.110, 95% confidential interval = 0.019–0.625) was the independent predictor of true-negative results. The area under the receiver operator characteristic (ROC) curve was 0.697 (P = 0.019). In the validation group, biopsy results for 47 patients were true negative, and 10 were false negative. When the predictor was used on the validation group, the area under the ROC curve was 0.759 (P = 0.011).

Conclusions

Most of the CNB-based benign results were true negatives, and CNB-based granulomatous inflammation could be considered a predictor of true-negative results.

"Napoleon Hat" Sign: A Distinctive Cytologic Clue to Reactive Pneumocytes

Various types of acute and subacute lung injury can cause severe reactive pneumocyte atypia, which may mimic malignant proliferations and present a major diagnostic pitfall. This particularly applies to cytologic preparations and frozen sections, where background inflammatory injury may be subtle or not apparent. Although several distinguishing morphologic features of reactive pneumocytes have been suggested, there is significant overlap with neoplastic proliferations. In this article, a highly distinctive but underrecognized feature of reactive pneumocytes is highlighted that can serve as a useful diagnostic clue. The feature refers to the distinctive pinched shape of reactive pneumocytes, for which the author has coined the term "Napoleon hat" sign to draw the analogy with the iconic headwear. The analogy vividly captures the distinctive shape of reactive pneumocytes, and can serve as a useful diagnostic and teaching tool in the interpretation of pulmonary specimens.

Atypical cells in pathology of endobronchial ultrasound-guided transbronchial biopsy of peripheral pulmonary lesions: incidence and clinical significance

BACKGROUND

Atypical cells may occasionally be the only pathologic finding in radial-probe endobronchial ultrasound (EBUS)-guided transbronchial biopsy (TBB) of peripheral pulmonary lesions (PPLs); however, it is uncertain how often we encounter such a situation and what clinical features can be used to identify these ambiguous PPLs, which are more likely to be malignant.

METHODS

From 2009 to 2016, consecutive patients referred for EBUS-guided TBB of PPLs and with pathology reports indicating atypical cells alone were included. Medical records were reviewed to extract patient demographics, clinical characteristics, procedural details and complications. The primary outcome was the final diagnosis of the PPLs on subsequent investigation. Multivariate logistic regression analysis was used to identify independent factors associated with a final malignant diagnosis.

RESULTS

One hundred sixty-five (7.2%) of 2291 patients had non-diagnostic TBB showing atypical cells. Benign and malignant diagnoses were subsequently obtained in 45 (27%) and 120 (73%) patients, respectively. The leading malignancy was lung adenocarcinoma; of note, a variety of benign lesions revealed cellular atypia on pathology, in particular, chronic inflammation, tuberculosis and pneumonia. Multivariate analysis indicated lesion appearance [solid vs. others; odds ratio (OR) 7.93; 95% confidence interval (CI) 2.94-21.40; P < 0.001] and probe position (adjacent to vs. within; OR 3.36; 95% CI 1.11-10.15; P = 0.032) were two significant factors predictive of a final diagnosis of malignancy.

CONCLUSIONS

One out of 14 EBUS-guided TBB procedures for PPLs exhibited atypical cells on pathology. Meticulous management strategies should be formulated to deal with these instances after taking into consideration lesion appearance, probe position and patient preferences.

Non-malignant pathological results on transthoracic CT guided core-needle biopsy: when is benign really benign?

AIM

To determine true negatives and characterise the variables associated with false-negative results when interpreting non-malignant results of computed tomography (CT)-guided lung biopsy.

MATERIALS AND METHODS

Nine hundred and fifty patients with initial non-malignant findings on their first transthoracic CT-guided core-needle biopsy (TTNB) were included in the study. Initial biopsy results were compared to definitive diagnoses established later.

RESULTS

The negative predictive value (NPV) of non-malignant diseases upon initial TTNB was 83.6%. When the biopsy results indicated specific infection or benign tumour (n=225, 26.1%), they all were confirmed true negative for malignancy later. Only one inconclusive "granuloma" diagnosis was false negative. All 141 patients (141/861, 16.4%) who were false negative for malignancy were from the "infection not otherwise specified (NOS)", "inflammatory diseases", or "inconclusive" groups. Age (p=0.002), cancer history (p<0.001), target size (p=0.003), and pneumothorax during lung biopsy (p=0.003) were found to be significant predictors of false-negative results; 47.6% (410/861) of patients underwent additional invasive examinations to reach a final diagnosis. Ultimately, 52.7% (216/410) were successfully diagnosed.

CONCLUSION

Specific infection, benign tumour, and granulomatous inflammation of first TTNBs were mostly true negative. Older age, history of cancer, larger target size, and pneumothorax were highly predictive of false-negative results for malignancies. In such cases, additional invasive examinations were frequently necessary to obtain final diagnoses.

Non-specific benign pathological results on transthoracic core-needle biopsy: how to differentiate false-negatives?

OBJECTIVES

To determine the negative predictive value (NPV) of non-specific benign results from cone-beam CT (CBCT)-guided transthoracic core-needle biopsy (TTNB) and identify predicting factors for false-negative for malignancies.

METHODS

From January 2009-December 2011, 1,108 consecutive patients with 1,116 lung lesions underwent CBCT-guided TTNB using an 18-gauge coaxial cutting needle. Among them, 226 patients with 226 TTNBs, initially diagnosed as non-specific benign, were included in this study. The medical charts, radiological or pathological follow-ups were reviewed to classify false-negative and true-negative results and to identify which variables were associated with false-negatives.

RESULTS

Of 226 lesions, 24 (10.6%) were finally confirmed as malignancies and 202 (89.4%) as benign, of which the NPV was 89.4% (202/226). Multivariate analysis revealed that part-solid nodule (PSN) (odds ratio (OR), 3.95; P = 0.022), a biopsy result of 'granulomatous inflammation' (OR, 0.04; P = 0.022), and exact location of needle tip within targets (OR, 0.37; P = 0.045) were significantly associated with false-negatives among initial non-specific benign biopsy results.

CONCLUSION

The NPV of the non-specific benign biopsy was 89.4%. PSN was a significant positive indicator, but a biopsy result of 'granulomatous inflammation' and exact location of needle tip within targets were significant negative indicators for false-negatives.

KEY POINTS

• The negative predictive value of the non-specific benign biopsy was 89.4%. • A part-solid nodule is a significant predictor for false-negative biopsy (OR = 3.95). • Pathological diagnosis of granulomatous inflammation is a robust indicator for 'true-negatives'. • Identifying needle tip within target lesions is a significant predictor for 'true-negatives'.

Authors attain comparable or slightly higher rates of citation publishing in an open access journal (CytoJournal) compared to traditional cytopathology journals - A five year (2007-2011) experience

BACKGROUND

The era of Open Access (OA) publication, a platform which serves to better disseminate scientific knowledge, is upon us, as more OA journals are in existence than ever before. The idea that peer-reviewed OA publication leads to higher rates of citation has been put forth and shown to be true in several publications. This is a significant benefit to authors and is in addition to another relatively less obvious but highly critical component of the OA charter, i.e. retention of the copyright by the authors in the public domain. In this study, we analyzed the citation rates of OA and traditional non-OA publications specifically for authors in the field of cytopathology.

DESIGN

We compared the citation patterns for authors who had published in both OA and traditional non-OA peer-reviewed, scientific, cytopathology journals. Citations in an OA publication (CytoJournal) were analyzed comparatively with traditional non-OA cytopathology journals (Acta Cytologica, Cancer Cytopathology, Cytopathology, and Diagnostic Cytopathology) using the data from web of science citation analysis site (based on which the impact factors (IF) are calculated). After comparing citations per publication, as well as a time adjusted citation quotient (which takes into account the time since publication), we also analyzed the statistics after excluding the data for meeting abstracts.

RESULTS

Total 28 authors published 314 publications as articles and meeting abstracts (25 authors after excluding the abstracts). The rate of citation and time adjusted citation quotient were higher for OA in the group where abstracts were included (P < 0.05 for both). The rates were also slightly higher for OA than non-OA when the meeting abstracts were excluded, but the difference was statistically insignificant (P = 0.57 and P = 0.45).

CONCLUSION

We observed that for the same author, the publications in the OA journal attained a higher rate of citation than the publications in the traditional non-OA journals in the field of cytopathology over a 5 year period (2007-2011). However, this increase was statistically insignificant if the meeting abstracts were excluded from the analysis. Overall, the rates of citation for OA and non-OA were slightly higher to comparable.

Diagnosis of lung cancer in small biopsies and cytology: implications of the 2011 International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification

The new International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society lung adenocarcinoma classification provides, for the first time, standardized terminology for lung cancer diagnosis in small biopsies and cytology; this was not primarily addressed by previous World Health Organization classifications. Until recently there have been no therapeutic implications to further classification of NSCLC, so little attention has been given to the distinction of adenocarcinoma and squamous cell carcinoma in small tissue samples. This situation has changed dramatically in recent years with the discovery of several therapeutic options that are available only to patients with adenocarcinoma or NSCLC, not otherwise specified, rather than squamous cell carcinoma. This includes recommendation for use of special stains as an aid to diagnosis, particularly in the setting of poorly differentiated tumors that do not show clear differentiation by routine light microscopy. A limited diagnostic workup is recommended to preserve as much tissue for molecular testing as possible. Most tumors can be classified using a single adenocarcinoma marker (eg, thyroid transcription factor 1 or mucin) and a single squamous marker (eg, p40 or p63). Carcinomas lacking clear differentiation by morphology and special stains are classified as NSCLC, not otherwise specified. Not otherwise specified carcinomas that stain with adenocarcinoma markers are classified as NSCLC, favor adenocarcinoma, and tumors that stain only with squamous markers are classified as NSCLC, favor squamous cell carcinoma. The need for every institution to develop a multidisciplinary tissue management strategy to obtain these small specimens and process them, not only for diagnosis but also for molecular testing and evaluation of markers of resistance to therapy, is emphasized.

Granulomatosis with polyangiitis initially misdiagnosed as lung cancer

Granulomatosis with Polyangiitis (GPA), which was formerly named Wegener's Granulomatosis (WG) is a systemic disease characterized by necrotizing granulomatous inflammation and vasculitis that primarily involves upper and lower respiratory tract, as well as kidneys. Diagnosing GPA on the basis of transthoracic fine needle aspiration (TFNA) may be problematic, as it can be misdiagnosed as cancer. We describe a patient with a probable GPA which was originally diagnosed as malignancy, but who responded to lung cancer chemotherapy.