Verification bias in diagnostic accuracy studies for fine- and core needle biopsy of salivary gland lesions in otolaryngology journals: a systematic review and analysis

[Frozen section biopsy for tumors of the submandibular triangle]

BACKGROUND

Diagnosis and treatment of submandibular lesions is challenging. Carcinomas, which frequently occur, should be surgically removed with sufficient safety margins, while simultaneously protecting functional structures. In particular, the preservation of neuronal structures with simultaneous tumor control suggests that single-stage concepts are appropriate, although they are not yet established. The aim of this study was to evaluate intraoperative frozen section biopsy as a possible basis for a one-stage surgical concept to thus prevent functional alterations by reoperation.

METHODS

A total of 114 consecutive patients with neoplastic lesions in whom the type of lesion could not be determined after ENT examination and imaging were included in the study. Patients with a known history of carcinoma or evidence of an acute inflammatory or carcinogenic primary lesion in the ENT examination and/or imaging were excluded. An intraoperative frozen section biopsy was performed to determine the presence of a carcinoma. Patient-related data and the reliability of the frozen section result were recorded comparatively.

RESULTS

Intraoperative frozen section biopsy was performed in a total of 114 patients. Carcinomas were diagnosed with a sensitivity of 87% and a specificity of 100%. There would thus not have been unnecessary radical surgery in a one-stage approach. In 26 of 30 patients with carcinoma, a second operation could have been avoided.

CONCLUSION

Intraoperative frozen section biopsy is potentially an important method to histologically confirm carcinomas and avoid two-stage procedures. The absence of false-positive findings would have prevented an unnecessary radical procedure in 100% of patients.

An artificial intelligence system for distinguishing between gastrointestinal stromal tumors and leiomyomas using endoscopic ultrasonography

BACKGROUND

Gastrointestinal stromal tumors (GISTs) and gastrointestinal leiomyomas (GILs) are the most common subepithelial lesions (SELs). All GISTs have malignant potential; however, GILs are considered benign. Current imaging cannot effectively distinguish GISTs from GILs. We aimed to develop an artificial intelligence (AI) system to differentiate these tumors using endoscopic ultrasonography (EUS).

METHODS

The AI system was based on EUS images of patients with histologically confirmed GISTs or GILs. Participants from four centers were collected to develop and retrospectively evaluate the AI-based system. The system was used when endosonographers considered SELs to be GISTs or GILs. It was then used in a multicenter prospective diagnostic test to clinically explore whether joint diagnoses by endosonographers and the AI system can distinguish between GISTs and GILs to improve the total diagnostic accuracy for SELs.

RESULTS

The AI system was developed using 10 439 EUS images from 752 participants with GISTs or GILs. In the prospective test, 132 participants were histologically diagnosed (36 GISTs, 44 GILs, and 52 other types of SELs) among 508 consecutive subjects. Through joint diagnoses, the total accuracy of endosonographers in diagnosing the 132 histologically confirmed participants increased from 69.7 % (95 % confidence interval [CI] 61.4 %-76.9 %) to 78.8 % (95 %CI 71.0 %-84.9 %; P = 0.01). The accuracy of endosonographers in diagnosing the 80 participants with GISTs or GILs increased from 73.8 % (95 %CI 63.1 %-82.2 %) to 88.8 % (95 %CI 79.8 %-94.2 %; P = 0.01).

CONCLUSIONS

We developed an AI-based EUS diagnostic system that can effectively distinguish GISTs from GILs and improve the diagnostic accuracy of SELs.

Adenoid cystic carcinoma. An indolent but aggressive tumour. Part A: from aetiopathogenesis to diagnosis

Adenoid cystic carcinoma (ACC) is a relatively rare tumour of the minor and major salivary glands. It is uncommon in the parotid gland while it is much more frequent in the submandibular gland and in minor salivary and mucinous glands (oral cavity, oropharynx, and paranasal sinuses). ACC may also arise in secretory glands located in other tissues, such as in the tracheobronchial tree, oesophagus, breast, lungs, prostate, uterine cervix, lachrymal and Bartholin’s glands, and skin. The natural history of ACC is characterised by an indolent growth rate, a relatively low probability of regional lymph node metastases and a high likelihood of haematogenous dissemination. ACC has been traditionally subdivided into three histological groups (cribriform, tubular, and solid) based on solid components of the tumour. Some studies have shown that tumours with a solid growth component have a rapid fatal course, compared to tumours without a solid growth component, but other studies have failed to correlate growth patterns with clinical course. The purpose of this review is to analyse the very large number of studies (sometimes contradictory) on ACC. In this first part, the aetiology, epidemiology, histopathology, clinical behaviour and diagnostic workup are examined.

Needle Biopsy Adequacy in the Era of Precision Medicine and Value-Based Health Care

CONTEXT.—

Needle biopsy of diseased tissue is an essential diagnostic tool that is becoming even more important as precision medicine develops. However, the capability of this modality to efficiently provide samples adequate for diagnostic and prognostic analysis remains quite limited relative to current diagnostic needs. For physicians and patients, inadequate biopsy frequently leads to diagnostic delay, procedure duplication, or insufficient information about tumor biology leading to delay in treatment; for health systems, this results in substantial incremental costs and inefficient use of scarce specialized diagnostic resources.

OBJECTIVE.—

To review current needle biopsy technology, devices, and practice with a perspective to identify current limitations and opportunities for improvement in the context of advancing precision medicine.

DATA SOURCES.—

PubMed searches of fine-needle aspiration and core needle biopsy devices and similar technologies were made generally, by tissue site, and by adequacy as well as by health economics of these technologies.

CONCLUSIONS.—

Needle biopsy adequacy can be improved by recognizing the importance of this diagnostic tool by promoting common criteria for needle biopsy adequacy; by optimizing needle biopsy procedural technique, technologies, clinical practice, professional education, and quality assurance; and by bundling biopsy procedure costs with downstream diagnostic modalities to provide better accountability and incentives to improve the diagnostic process.

The Use and Misuse of Statistical Methods in Cytopathology Studies: Review of 6 Journals

Background

The misuse of statistical methods in diagnostic accuracy studies has been criticized in many publications.

Objective

To assess the use and misuse of statistical methods in medical journal articles.

Methods

We reviewed 141 original articles from 6 cytopathology journals published in 2014.

Results

In total, 16 articles used no descriptive statistics and 66 articles used no inferential statistics. Also, 82 articles did not report using any tests for diagnostic accuracy. The most commonly adopted statistical measure for diagnostic accuracy was sensitivity, followed by specificity. The most common inferential statistical methods were χ2 testing, the Fisher exact test, and the Cohen kappa coefficient, respectively. Only 78 articles were free of statistical errors. "No statistics were used although statistical methods were required" was the most common type of error, followed by "failure to select proper statistical methods."

Conclusion

Our assessment of use of statistical methods in this subsection of pathology demonstrated a need for improvement.

Fine Needle Aspiration Cytology for Neck Masses in Childhood. An Illustrative Approach

The primary indication of fine-needle aspiration cytology of the head and neck region is a thyroid nodule or a mass located in the cervical area or the head. Although a thyroid nodule may raise the suspicion of malignancy, less than one in 20 cases results in a carcinoma. In addition, the list of differential diagnoses is quite different according to the age of the patient. A number of benign lesions, such as branchial cysts, sialadenosis, and sialoadenitis are often seen in childhood and youth. The malignant lesions that are on the top of the list of a pediatric mass of the head and neck (H&N) region include rhabdomyosarcoma, neuroblastoma, and papillary carcinoma of the thyroid gland. This critical review of the diagnostic features of a pediatric mass of the H&N region is accompanied by panels of several cytology features that may be of help to the cytopathologist and clinician.

Feasibility of a novel classification for parotid gland cytology: A retrospective review of 512 cytology reports taken from 4 United Kingdom general hospitals

BACKGROUND

A novel classification for parotid cytology has been previously proposed. The purpose of this study was to assess the feasibility and clinical relevance of this classification.

METHOD

Between 2010 and 2013, cytology reports from 4 United Kingdom general hospitals were retrospectively classified and compared to histological and clinical outcomes.

RESULTS

Based on the cytology reports of 512 patients, we revised our previous "P" system to a "Sal" (salivary) classification to encompass all cytologic outcomes. The percentage of patients with a final diagnosis of malignancy according to each category heading were: Sal 1 (inadequate) 7.9%; Sal 2I (nonneoplastic) 10%; Sal 2N (benign neoplastic) 1.4%; Sal 3 (atypical) 20.4%; Sal 4 (suspicious) 52.6%; Sal 5P (primary salivary gland malignancy) 71.4%; Sal 5NOS (malignancy not otherwise specified) 100%; and Sal 5M (metastasis) 91.7%.

CONCLUSION

By stratifying the probability of encountering a malignant neoplasm, the classification could guide clinical management decisions. A future prospective study is warranted. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1708-1716, 2016.

Mucoepidermoid Carcinoma Associated with Osteosarcoma in a True Malignant Mixed Tumor of the Submandibular Region

Introduction. True malignant mixed tumor, also known as carcinosarcoma, is a rare tumor of the salivary gland composed of both malignant epithelial and malignant mesenchymal elements. Frequently carcinosarcoma arises in the background of a preexisting pleomorphic adenoma; however, if no evidence of benign mixed tumor is present, the lesion is known as carcinosarcoma “de novo.” We reported the first case of true malignant mixed tumor of the submandibular gland composed of high grade mucoepidermoid carcinoma associated with osteosarcoma. Case Presentation. A 69-year-old Caucasian male came to our department complaining of the appearance of an asymptomatic left submandibular neoformation progressively increasing in size over 3 months. We opted for surgical treatment. Histological examination confirmed the diagnosis of carcinosarcoma with the coexistence of high grade mucoepidermoid carcinoma and osteosarcoma. Conclusion. To the best of our knowledge, in the true malignant mixed tumor of the submandibular gland, mucoepidermoid carcinoma associated with osteosarcoma has never been previously reported.

Accuracy of Core Needle Biopsy Versus Fine Needle Aspiration Cytology for Diagnosing Salivary Gland Tumors

BACKGROUND

Core needle biopsy is a relatively new technique used to diagnose salivary gland lesions, and its role in comparison with fine needle aspiration cytology needs to be refined.

METHODS

We compared the results of 228 ultrasound-guided core needle biopsy and 371 fine needle aspiration procedures performed on major salivary gland tumors with their postoperative histological diagnoses.

RESULTS

Core needle biopsy resulted in significantly higher sensitivity and more accurate tumor subtyping, especially for malignant tumors, than fine needle aspiration. No patient developed major complications after core needle biopsy.

CONCLUSIONS

We recommend ultrasoundguided core needle biopsy as the primary diagnostic tool for the preoperative evaluation of patients with salivary gland lesions, especially when malignancy is suspected.

Comparison of fine-needle aspiration and core needle biopsy under ultrasonographic guidance for detecting malignancy and for the tissue-specific diagnosis of salivary gland tumors

BACKGROUND AND PURPOSE

Diagnostic test accuracy studies for ultrasonography-guided fine-needle aspiration and ultrasonography-guided core needle biopsy have shown inconclusive results due to their heterogenous study designs. Our aim was to compare the diagnostic accuracy of ultrasonography-guided fine-needle aspiration versus ultrasonography-guided core needle biopsy for detecting malignant tumors of the salivary gland and for the tissue-specific diagnosis of salivary gland tumors in a single tertiary hospital.

MATERIALS AND METHODS

This retrospective study was approved by our institutional review board and informed consent was waived. Four hundred twelve patients who underwent ultrasonography-guided fine-needle aspiration (n = 155) or ultrasonography-guided core needle biopsy (n = 257) with subsequent surgical confirmation or clinical follow-up were enrolled. We compared the diagnostic accuracy of ultrasonography-guided fine-needle aspiration and ultrasonography-guided core needle biopsy regarding malignant salivary gland tumors and the correct tissue-specific diagnosis of benign and malignant tumors. We also tested the difference between these procedures according to the operator's experience and lesion characteristics.

RESULTS

The inconclusive rates of ultrasonography-guided fine-needle aspiration and ultrasonography-guided core needle biopsy were 19% and 4%, respectively (P < .001). The overall accuracy of ultrasonography-guided core needle biopsy for diagnosing malignant tumors was significantly higher than that of ultrasonography-guided fine-needle aspiration (P = .024). The correct tissue-specific diagnosis rates of ultrasonography-guided fine-needle aspiration and ultrasonography-guided core needle biopsy were 95% versus 97% for benign tumors (P = .648) and 67% versus 80% for malignant tumors (P = .310). Trainees showed significantly lower accuracy with ultrasonography-guided fine-needle aspiration than with ultrasonography-guided core needle biopsy for diagnosing malignant tumors (P = .021). There was no difference between the diagnostic accuracy of ultrasonography-guided fine-needle aspiration and ultrasonography-guided core needle biopsy according to the internal composition of the lesions. There were no complications requiring intervention or hospitalization in our patients.

CONCLUSIONS

Ultrasonography-guided core needle biopsy is superior to ultrasonography-guided fine-needle aspiration in detecting and characterizing malignant tumors of the salivary gland and could emerge as the diagnostic method of choice for patients presenting with a salivary gland mass.

Verification and classification bias interactions in diagnostic test accuracy studies for fine-needle aspiration biopsy

BACKGROUND

Reliable estimates of accuracy are important for any diagnostic test. Diagnostic accuracy studies are subject to unique sources of bias. Verification bias and classification bias are 2 sources of bias that commonly occur in diagnostic accuracy studies. Statistical methods are available to estimate the impact of these sources of bias when they occur alone. The impact of interactions when these types of bias occur together has not been investigated.

METHODS

We developed mathematical relationships to show the combined effect of verification bias and classification bias. A wide range of case scenarios were generated to assess the impact of bias components and interactions on total bias.

RESULTS

Interactions between verification bias and classification bias caused overestimation of sensitivity and underestimation of specificity. Interactions had more effect on sensitivity than specificity. Sensitivity was overestimated by at least 7% in approximately 6% of the tested scenarios. Specificity was underestimated by at least 7% in less than 0.1% of the scenarios.

CONCLUSIONS

Interactions between verification bias and classification bias create distortions in accuracy estimates that are greater than would be predicted from each source of bias acting independently.