Diagnostic Accuracy of Fine-Needle Aspiration Cytology for Discrimination of Squamous Cell Carcinoma from Adenocarcinoma in Non-Small Cell Lung Cancer: A Systematic Review and Meta-Analysis

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.

[Prevention, Diagnosis, Therapy, and Follow-up of Lung Cancer - Interdisciplinary Guideline of the German Respiratory Society and the German Cancer Society - Abridged Version]

The current S3 Lung Cancer Guidelines are edited with fundamental changes to the previous edition based on the dynamic influx of information to this field:The recommendations include de novo a mandatory case presentation for all patients with lung cancer in a multidisciplinary tumor board before initiation of treatment, furthermore CT-Screening for asymptomatic patients at risk (after federal approval), recommendations for incidental lung nodule management , molecular testing of all NSCLC independent of subtypes, EGFR-mutations in resectable early stage lung cancer in relapsed or recurrent disease, adjuvant TKI-therapy in the presence of common EGFR-mutations, adjuvant consolidation treatment with checkpoint inhibitors in resected lung cancer with PD-L1 ≥ 50%, obligatory evaluation of PD-L1-status, consolidation treatment with checkpoint inhibition after radiochemotherapy in patients with PD-L1-pos. tumor, adjuvant consolidation treatment with checkpoint inhibition in patients withPD-L1 ≥ 50% stage IIIA and treatment options in PD-L1 ≥ 50% tumors independent of PD-L1status and targeted therapy and treatment option immune chemotherapy in first line SCLC patients.Based on the current dynamic status of information in this field and the turnaround time required to implement new options, a transformation to a "living guideline" was proposed.

Rare ectopic thyroid tissue as multiple bilateral pulmonary nodules: a case report and literature review

Background

The prevalence of ectopic thyroid tissue is 1 in every 100,000 to 300,000 persons in the general population, and ectopic thyroid tissue in the bilateral lung lobes is even rarer. Due to its rarity, there is no definitive or standard guidance on the diagnosis and treatment of ectopic thyroid tissue presenting as multiple bilateral pulmonary nodules.

Case presentation

A 56-year-old woman presented with multiple bilateral pulmonary nodules, and the patient had a history of hyperthyroidism but had no symptoms of ectopic thyroid tissue. Computed tomography (CT) demonstrated multiple solid nodules in both lungs, and the largest nodule (sized 15 × 14 mm) was located in segment 5 of the upper left lung. The initial diagnosis based on imaging was metastatic malignancies. Positron emission tomography-computed tomography (PET-CT) showed multiple bilateral intrapulmonary nodules that had slightly increased metabolism (SUVmax 1.7). The largest pulmonary nodule and another nodule in the left lung were resected by video-assisted thoracoscopy surgery (VATS). The pathological and immunohistochemical (IHC) examinations confirmed a diagnosis of ectopic thyroid tissue. No postoperative adjuvant therapy was given, and the patient was discharged 3 days after the operation and had regular follow-up examinations.

Conclusion

The diagnosis of ectopic thyroid tissue in the bilateral lung lobes is extremely difficult and should be considered carefully. PET-CT and surgical resection of intrapulmonary nodules are alternatives for clinicians in diagnosing ectopic thyroid tissue. Regular postoperative follow-up is needed.

Efficacy of Osimertinib in Lung Squamous Cell Carcinoma Patients with EGFR Gene Mutation–Case Report and A Literature Review

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer and the leading cause of cancer-related mortality worldwide. It is responsible for 80–85% of lung cancer cases. NSCLC can be divided into several groups, led by adenocarcinoma (ADC)–40–50% and squamous cell carcinoma (SCC)–20–30%. The development of new molecular therapies targeting particular abnormalities such as mutations in the EGFR (Epidermal Growth Factor Receptor) gene or ROS1 or ALK genes rearrangements resolved in novel strategies in advanced NSCLC management. EGFR mutation occurs mostly in patients with ADC and those patients are mostly females with no or light smoking history. The hereby presented patient fitted the ADC characteristics, while they were diagnosed with SCC. The unusual diagnosis implied further genetic testing, which established the occurrence of L858R substitution in exon 21 in the EGFR gene. A 63-year-old female was admitted to the unit due to a dry cough, pain in the right chest area and dyspnoea. When diagnosed, the patient had a peripheral mass in the right lung superior lobe (55 × 40 mm), satellite nodules in the apex of the same lung and packets of disintegrating lymph nodes. Positron Emission Tomography (PET-CT) confirmed a diffuse neoplastic process qualified as stage IV on the TNM scale. Due to EGFR gene mutation, the woman was administered osimertinib, however, the treatment did not succeed, and other therapeutic solutions were undertaken. The patient died 10 months after diagnosis. Patients with advanced ADC harboring EGFR mutation can receive osimertinib, a third-generation tyrosine kinase inhibitor (TKI), however, the use of TKIs in SCC remains controversial. In some published cases, osimertinib treatment led to success, in others, the therapy did not result in the expected final effect. Small sample groups and diverse molecular backgrounds indicate the need for further research in this field. Thus, the treatment decision-making process in those patients overall remains extremely demanding and ambiguous.

Diagnostic utility of fine needle aspiration cytology and core biopsy histopathology with or without immunohistochemical staining in the subtyping of the non-small cell lung carcinomas: Experience from an academic centre in Turkey

INTRODUCTION

This retrospective morphological study compared the results of fine needle aspiration (FNA) cytology, haematoxylin-eosin (HE)-stained samples and immunohistochemical (IHC)-stained core needle biopsy (CNB) histology samples for primary non-small cell lung cancer (NSCLC) subtyping. We assessed the diagnostic utility of these methods to investigate the contribution of each method to NSCLC subtyping. We also identified the point at which NSCLC subtyping could be performed using histomorphology alone without IHC.

METHODOLOGY

Concurrent FNA and CNB specimens obtained via a single computed tomography-guided procedure and diagnosed as NSCLC in the Pathology Department of our university within 3 years were reviewed. The results of FNA samples, HE-stained biopsies and IHC-stained biopsies were compared according to subtype.

RESULTS

A total of 141 subjects were enrolled in the study. For subtyping, FNA provided an accurate diagnosis in 70 (55.1%) of 127 eligible subjects after the exclusion of 14 cases determined as not otherwise specified. CNB histology without IHC achieved a diagnosis in 53 (41.7%) of 127 subjects, which was a significant difference (P < .05). The compatibility rate between HE-stained biopsy samples and IHC-stained biopsy samples was 41.7% (53/127).

CONCLUSION

The diagnosis rates achieved using FNA, HE-stained CNB samples and IHC-stained CNB samples were 54.6% (77/141), 37.6% (53/141) and 90.1% (127/141), respectively. The subtype was identified in 55.1% of the subjects evaluated using FNA and 41.7% of subjects assessed using HE-stained biopsy samples without IHC. FNA provided a better result for squamous cell carcinoma than adenocarcinoma (55.1% vs 47.6%), but the diagnosing of adenocarcinoma and squamous cell carcinoma using HE-stained biopsy samples was similar (42% vs 41.7%).

Optimizing Tissue Use: A Step-wise Approach to Diagnosing Squamous Cell Lung Carcinoma on Small Biopsies

Background:

Histologic subtyping of lung cancer has significant implications for treatment planning. Accurate diagnosis based on cytology/small biopsy specimens is challenging and frequently determined by morphology, as material is often not sufficient for immunohistochemical studies (IHC). We investigated the concordance between the rates of diagnosis from cytology/small biopsies compared with surgical specimens in patients with squamous cell lung cancer (SCC) and the utility of IHC for diagnostic precision in lung cancer subtyping.

Methods:

We conducted a 5-year retrospective analysis identifying cases of SCC diagnosed on cytology/small biopsies ± IHC and compared them with subsequent surgical specimens when available. The number of patients with SCC on surgical biopsy and the concordance between cytology ± IHC was determined.

Results:

Over the 5-year period (2011-2015), 231 cases were identified. Surgery was performed on 66 cases (28.5%), of which 87.9% concurred with cytological diagnosis (95% exact binomial confidence interval [CI] = 77.5%-94.6%). There were 36 cases diagnosed in 2014 and 2015 with IHC data. Of those cytology cases with IHC (n = 12), SCC was confirmed by surgery in 91.7% (95% CI = 61.5%-99.8%). Of those without IHC (n = 24), 95.8% were confirmed SCC by surgery (95% CI = 78.9%-99.9%). These rates were not different (Fisher exact test). All cases with IHC were morphologically squamous.

Conclusions:

Our data demonstrate that diagnostic precision of identifying SCC by cytology/small biopsy is comparable with or without additional IHC studies. We recommend judicious use of IHC on cytology specimens, reserving it for cases where cytomorphology is equivocal. Tissue should be preserved for molecular analysis, which may have therapeutic implications.

Cytomorphological criteria for separation of pulmonary adenocarcinomas from squamous cell carcinomas: A statistical learning approach

BACKGROUND

Current therapy requires separation of non-small cell carcinomas into adenocarcinomas (AC) and squamous cell carcinomas (SCC). A meta-analysis has shown a pooled diagnostic sensitivity of 63% and specificity of 95% for the diagnosis of AC. While a number of cytomorphological features have been proposed for separation of AC from SCC, we are unaware of a statistically based analysis of cytomorphological features useful for separation of these two carcinomas. We performed logistic regression analysis of cytological features useful in classifying SCC and AC.

DESIGN

Sixty-one Papanicolaou-stained fine needle aspiration specimens (29 AC/32 SCC) were reviewed by two board-certified cytopathologists for nine features (eccentric nucleoli, vesicular chromatin, prominent nucleoli, vacuolated cytoplasm, 3-dimensional cell balls, dark non-transparent chromatin, central nucleoli, single malignant cells and spindle-shaped cells). All cytological specimens had surgical biopsy results. Inter-rater agreement was assessed by Cohen's κ. Association between features and AC was determined using hierarchical logistic regression model where feature scores were nested within reviewers. A model to classify cases as SCC or AC was developed and verified by k-fold verification (k = 5). Classification performance was assessed using the area under the receiver operating characteristic curve.

RESULTS

Observed rater agreement for scored features ranged from 49% to 82%. Kappa scores were clustered in three groups. Raters demonstrated good agreement for prominent nucleoli, vesicular chromatin and eccentric nuclei. Fair agreement was seen for 3-dimensional cell balls, dark non-transparent chromatin, and presence of spindle-shaped cells. Association of features with adenocarcinoma showed four statistically significant associations (P < 0.001) with adenocarcinoma. These features were prominent nucleoli, vesicular chromatin, eccentric nuclei and three-dimensional cell balls. Spindle-shaped cells and dark non-transparent chromatin were negatively associated with adenocarcinoma.

CONCLUSIONS

Logistic regression analysis demonstrated six features helpful in separation of AC from SCC. Prominent nucleoli, vesicular chromatin, cell balls and eccentric nucleoli were positively associated with AC and demonstrated a P value of 0.001 or less. The presence of dark, non-transparent chromatin and spindle-shaped cells favoured the diagnosis of SCC.

The Role of Ancillary Techniques in Pulmonary Cytopathology

Ancillary techniques play an essential role in pulmonary cytopathology. Immunoperoxidase and special stains are by far the most common ancillary techniques used in cytopathology; however, the role of molecular diagnosis is growing, especially in the fields of pulmonary oncology and infectious disease. In this article, we review the uses of ancillary techniques in lung tumor diagnosis, lung tumor classification, predictive marker determination, primary versus metastasis differential diagnosis, and infectious organism detection.