Macroscopic assessment of pulmonary fine needle aspiration biopsies: correlation with cytological diagnostic yield

Computed-Tomography-Guided Lung Biopsy: A Practice-Oriented Document on Techniques and Principles and a Review of the Literature

Computed tomography (CT)-guided lung biopsy is one of the oldest and most widely known minimally invasive percutaneous procedures. Despite being conceptually simple, this procedure needs to be performed rapidly and can be subject to meaningful complications that need to be managed properly. Therefore, knowledge of principles and techniques is required by every general or interventional radiologist who performs the procedure. This review aims to contain all the information that the operator needs to know before performing the procedure. The paper starts with the description of indications, devices, and types of percutaneous CT-guided lung biopsies, along with their reported results in the literature. Then, pre-procedural evaluation and the practical aspects to be considered during procedure (i.e., patient positioning and breathing) are discussed. The subsequent section is dedicated to complications, with their incidence, risk factors, and the evidence-based measures necessary to both prevent or manage them; special attention is given to pneumothorax and hemorrhage. After conventional CT, this review describes other available CT modalities, including CT fluoroscopy and cone-beam CT. At the end, more advanced techniques, which are already used in clinical practice, like fusion imaging, are included.

Diagnostic significance of clay-like materials aspirated from thyroid nodules

Objective

The simplest way to determine the adequacy of aspirated materials is the on-site gross visual assessment of aspirated materials. However, few studies have examined the gross findings of thyroid aspirates. This study aimed to clarify the diagnostic significance of clay-like material aspirated from thyroid nodules.

Material and Methods

We reviewed 69,848 thyroid nodules that underwent aspiration cytology at Kuma Hospital between January 2007 and August 2021. Among them, 355 (0.5%) nodules with aspirated materials described as clay-like materials were retrospectively examined.

Results

Among 355 nodules, 322 (90.7%) were categorized as cystic fluid or benign. The aspirated materials were mainly composed of non-epithelial components, including colloid or proteinaceous materials, foamy histiocytes, and degenerative red blood cells. In original ultrasound reports, the incidence of intermediate and high suspicion was 11.0%. Malignant cells were observed in 21 nodules (5.9%), one-third of which were papillary thyroid carcinomas. The materials aspirated from papillary and follicular thyroid carcinomas exhibited necrotic carcinoma cells derived from infarcted areas. The overall risk of malignancy was 3.9%. The risk of malignancy in nodules interpreted as highly suspicious on ultrasound examination was 37.5%.

Conclusion

As clay-like materials aspirated from thyroid nodules were considered sufficient specimens, the recognition contributes to avoiding unnecessary second punctures. The presence of clay-like materials was indicative of the colloid and/or blood components of benign cystic lesions, or, more rarely, of infarcted carcinoma. The ultrasound examination results tended to overestimate nodules. We should reaffirm that on-site gross visual assessment of aspirated materials is a fast and reasonably accurate predictor of the on-site adequacy of the samples.

Gross Appearance of Fine Needle Aspiration Smears: Can Adequacy of the Sample be Assessed and Correlated with their Microscopic Cytological Yield

Background

Fine needle aspiration cytology (FNAC) is a simple procedure that is widely accepted as a first-line investigation. It should ideally be performed near the patient with microscopic assessment for evaluation of adequacy of aspirate. Since this is not always possible, a worthwhile substitute is to assess the gross appearance of the material obtained. This study was aimed to determine the value of this alternative rapid, bed-side approach.

Method

This study was carried out in a tertiary care hospital for a duration of 1 year, where 50 cases undergoing FNAC in the out-patient department (OPD) were included. Unstained smears of commonly encountered lesions were photographed and assessed by three independent observers, who graded them into four grades, viz. Grade 1: unlikely to contain diagnostic material. Grade 2: possibly contains diagnostic material. Grade 3: probably contains diagnostic material. Grade 4: material suggesting a specific diagnosis. Results were subsequently compared with the microscopic findings of stained smears.

Results

Distribution of the 50 cases between grades 1, 2, 3, and 4 were 5, 6, 17, and 22, respectively.

Conclusion

Gross appearances of FNA smears are helpful in predicting the adequacy of the sample and sometimes the final microscopic diagnosis. The cellularity of a sample can be gauged by inspection and sometimes a likely diagnosis can be made. Some lesions show typical gross appearance easily detected by the experienced eye so a likely diagnosis can be predicted prior to microscopic examination. However, near-patient microscopic assessment of FNA specimens for rapid onsite evaluation, if available, should be the preferred mode.

CT-guided coaxial biopsy of malignant lung lesions: are cores from 20-gauge needle adequate for histologic diagnosis and molecular analysis?

Background

To determine the number of cores adequate for histopathologic diagnosis as well as evaluate the success rate of molecular analyses in CT-guided percutaneous core needle biopsy (PCNB) for malignant pulmonary lesions using a 20-guage coaxial needle.

Methods

Biopsy records of 196 malignant lung lesions were reviewed. Core obtained from each needle pass was put in a separate container for individual pathological analysis. Types of molecular analysis attempted and their success rates were recorded for each patient. We categorized each patient into one of six groups according to the number of cores (n=1, n=2, n=3, n=4, n=5, n≥6) acquired, and diagnostic sensitivity for histopathologic diagnosis was calculated for each core in each group. In order to assess the increase in cumulative sensitivity up to 4th core, the data from 1st to 4th needle passes in 4-, 5-, and ≥6-core groups were pooled and cumulative diagnostic sensitivities up to 4th core were calculated.

Results

Of 196 cases of lung malignancies, five different types of molecular studies (EGFR mutation, ALK translocation, KRAS mutation, RET and ROS1 rearrangements) were attempted with PCNB specimens in 100 cases and successfully done in 96 cases (96.0%). In ≥4-core group (4-, 5-, and ≥6-core groups combined; n=148), cumulative sensitivity increased from 83.8% to 89.9% between 1st and 2nd cores, 89.9% to 93.2% between 2nd and 3rd cores, and 93.2% to 94.6% between 3rd and 4th cores.

Conclusions

The cumulative diagnostic sensitivity for the histopathologic diagnosis increases significantly between the second and fourth sampling. Multiple samples obtained with a 20-guage coaxial needle are adequate and have a high success rate for various molecular studies for lung malignancy.

Molecular testing on endobronchial ultrasound (EBUS) fine needle aspirates (FNA): Impact of triage

BACKGROUND

Endobronchial ultrasound (EBUS)-guided fine needle aspiration (FNA) is performed to diagnose and stage lung cancer. Multiple studies have described the value of Rapid On-Site Evaluation (ROSE), but often the emphasis is upon diagnosis than adequacy for molecular testing (MT). The aim was to identify variable(s), especially cytology-related, that can improve MT.

METHODS

A search for EBUS-FNAs with ROSE was conducted for lung adenocarcinomas or when this diagnosis could not be excluded. All such cases underwent reflex MT on cell blocks. The impact of cytology-related variables [i.e., number of pass(es), dedicated pass(es) directly into media, cytotechnologist (CT), laboratory technician (LT) and triage with 1 or >1 cytologist] was evaluated. The latter category was divided into Group A [ROSE, triage and slide preparation by cytopathologist (CP) and CT at start of the procedure] and Group B (ROSE only by CT or by CT/CP after start of procedure; triage and slide preparation by CT or clinical staff). The impact of all these variables on MT was assessed.

RESULTS

A total of 100 cases were identified, and 79 had sufficient tissue for MT. Of all variables evaluated, MT was positively affected by performing a direct dedicated pass (P = 0.013) and ROSE by Group A (P = 0.033).

CONCLUSIONS

ROSE with appropriate triage, including performing a dedicated pass and proper slide preparation, improves MT, and this is enhanced by having >1 cytologist at the start of the procedure. In the era of personalized medicine, "adequate" should denote sufficient tissue for diagnosis and MT.

Predictors of False-Negative Results from Percutaneous Transthoracic Fine-Needle Aspiration Biopsy: An Observational Study from a Retrospective Cohort

PURPOSE

We investigated factors predictive of false-negative pulmonary lesions with nonspecific benign cytology results on percutaneous transthoracic fine-needle aspiration biopsy (FNAB).

MATERIALS AND METHODS

We included 222 pulmonary lesions that had a nonspecific benign result from percutaneous transthoracic FNAB between March 2005 and December 2012, and were confirmed by subsequent pathologic results or adequate clinical follow up over at least 2 years. Clinical, imaging, and biopsy procedure-related findings were compared between lesions with a final diagnosis of malignancy (false-negative) and lesions with a benign diagnosis (true-negative). Multivariate logistic regression analysis was performed to identify significant predictors of false-negatives.

RESULTS

Of 222 lesions, 115 lesions were proved to be false-negatives, and 107 were true-negatives. Compared with the true-negatives, false-negative lesions showed significantly older age (p=0.037), higher maximum standardized uptake value (SUVmax) on positron emission tomography (p=0.001), larger lesion size (p=0.007), and lesion characteristics of a subsolid nodule (p=0.007). On multivariate logistic regression analysis, SUVmax, lesion size, and lesion characteristics were significant predictors of false-negative results.

CONCLUSION

Among the clinical, radiologic, and procedure-related factors analyzed, high SUVmax, large lesion size, and subsolid lesions were useful for predicting malignancy in pulmonary lesions with nonspecific benign cytology results on FNAB.

Pneumothorax after transthoracic needle biopsy of lung lesions under CT guidance

Transthoracic needle biopsy (TTNB) is done with imaging guidance and most frequently by a radiologist, for the aim is to diagnose a defined mass. It is integral in the diagnosis and treatment of many thoracic diseases, and is an important alternative to more invasive surgical procedures. FNAC is a method of aspiration cytopathology, which with transthoracic biopsy ("core biopsy") is a group of percutaneous minimally invasive diagnostic procedures for exploration of lung lesions. Needle choice depends mostly upon lesion characteristics and location. A recent innovation in biopsy needles has been the introduction of automatic core biopsy needle devices that yield large specimens and improve the diagnostic accuracy of needle biopsy. Both computed tomography and ultrasound may be used as imaging guidance for TTNB, with CT being more commonly utilized. Common complications of TTNB include pneumothorax and hemoptysis. The incidence of pneumothorax in patients undergoing TTNB has been reported to be from 9-54%, according to reports published in the past ten years, with an average of around 20%. Which factors statistically correlate with the frequency of pneumothorax remain controversial, but most reports have suggested that lesion size, depth and the presence of emphysema are the main factors influencing the incidence of pneumothorax after CT-guided needle biopsy. On the contrary, gender, age, and the number of pleural passes have not been shown to correlate with the incidence of pneumothorax. The problem most responsible for complicating outpatient management, after needle biopsy was performed, is not the presence of the pneumothorax per se, but an increase in the size of the pneumothorax that requires chest tube placement and patient hospitalization. Although it is a widely accepted procedure with relatively few complications, precise planning and detailed knowledge of various aspects of the biopsy procedure is mandatory to avert complications.

Maximizing the yield of lymph node cytology: Lessons learned from rapid onsite evaluation of image- and endoscopic-guided biopsies of hilar and mediastinal lymph nodes

The evaluation of mediastinal and hilar lymph nodes for tissue diagnosis and staging of lung cancer is now commonly performed by minimally invasive, nonsurgical procedures such as computed tomography-guided fine-needle aspiration and endobronchial ultrasound-guided transbronchial needle aspiration. Ensuring that a sufficient quantity of cellular material has been acquired to enable multiple studies has become a priority issue in the era of personalized medicine, especially for patients with lung cancer, and this can be accomplished by rapid onsite evaluation (ROSE). This commentary focuses on the use of ROSE in guided procedures, especially for hilar and mediastinal lymph node aspirates, and describes an algorithm for handling these specimens.

The utility of assessing the gross appearances of FNA specimens

OBJECTIVE

Ideally, fine needle aspiration (FNA) cytology should be performed with near-patient assessment of the adequacy of the specimen by a cytopathologist. However, this is often not feasible. A cruder alternative is for the FNA practitioner to examine the gross appearances of the specimen and to try to predict the its quality. This study set out to determine the value of this approach.

METHODS

The study was conducted in tertiary public hospitals in New Zealand and the UK. FNA gross material grading was performed by a variety of pathologists on FNA samples taken using manual guidance and image guidance. The FNA gross material grade was compared with the findings on microscopic examination.

RESULTS

Nine out of 123 FNA samples were assessed as Grade 1 (unlikely to contain diagnostic material). All were subsequently reported as having insufficient diagnostic tissue on microscopic examination. Forty-two of the FNA samples were assessed as Grade 2 (possibly contains diagnostic material) and 46 as Grade 3 (probably contains diagnostic material). None from either of these grades was reported as showing insufficient diagnostic material on microscopic examination. Twenty-six cases were reported as Grade 4 (material suggesting a specific diagnosis). None of these was reported as showing insufficient diagnostic material on microscopic examination. The most common Grade 4 provisional diagnosis was that of a colloid cyst or colloid nodule of the thyroid (seven cases). Only two cases had misleading Grade 4 provisional diagnoses. Both were thought to be pus on gross examination but showed necrotic carcinoma on microscopic examination.

CONCLUSIONS

The gross appearances of FNA samples can usually predict the adequacy of the samples and sometimes predict the final microscopic diagnosis. However, near-patient microscopic assessment of FNA specimens is preferable if available.