Diagnostic utility and pitfalls of intraoperative pulmonary imprint cytology based on final pathological diagnoses

Diagnostic value of intraoperative fine-needle aspiration cytologic diagnosis versus frozen section-based histopathologic diagnosis in thoracic malignancies: A single institution's experience

BACKGROUND

Primary lung cancer is the leading cause of cancer death in the United States. Most lung cancers are diagnosed in an outpatient setting, but a subset requires intraoperative diagnosis. Two intraoperative diagnostic methods are available, frozen section (FS) and fine needle aspiration (FNA) cytology. This study compares intraoperative FNA cytology and FS based diagnosis in thoracic malignancies within the same clinical practice.

METHODS

Pathology reports from thoracic intraoperative FNA cytology or FS (January 2017-December 2019) were reviewed. Resection diagnosis was the gold standard. If unavailable, concurrent biopsy and final FNA cytology diagnosis were the gold standard.

RESULTS

Of 300 FNA specimens (155 patients), 142 (47%) cases were benign, and 158 (53%) were malignant. Adenocarcinoma was the most common malignant diagnosis (40%), followed by squamous cell carcinoma (26%), neuroendocrine tumors (18%), and other (16%). Intraoperative FNA yielded 88% sensitivity, 99% specificity, and 92% accuracy (p < .001). Of 298 FS specimens (252 patients), 215 (72%) cases were malignant and 83 (28%) were benign. Adenocarcinomas was the most common malignant diagnosis (48%), followed by squamous cell carcinoma (25%), metastatic carcinomas (13%), and other (14%). FS yielded 97% sensitivity, 99% specificity, and 97% accuracy (p < .001).

CONCLUSION

Our findings confirm FS is the gold standard for intraoperative diagnosis. FNA cytology may be useful as a non-invasive, inexpensive initial diagnostic tool intraoperatively, given the similar specificity (99% FNA, 99% FS) and accuracy (92% FNA, 97% FS). Negative FNA could be followed by the costlier and invasive FS. We encourage surgeons to utilize intraoperative FNA first.

Accuracy of imprint cytology and frozen section histology for intraoperative diagnosis of ovarian epithelial tumors: A comparative study and proposed algorithm

BACKGROUND

Appropriate surgical treatment of epithelial ovarian tumors is reliant on intraoperative diagnosis. A retrospective study to compare the diagnostic accuracies of imprint cytology (IC) with frozen section histology (FSH) in these tumors was performed.

METHODS

About 78 cases of IC-based and FSH-based diagnoses against the final histopathologic diagnoses in terms of both histologic subtype (serous, mucinous, endometrioid, or clear cell tumor) and behavioral type (benign, borderline, or malignant) were compared. The cytomorphologic features of the tumor cells (nuclear atypia, papillary clusters, adenoma cells, and necrosis) in relation to behavioral types were also evaluated.

RESULTS

While the diagnostic accuracy of IC and FSH were similar with respect to behavioral type (87% and 88%, respectively), the diagnostic accuracy of IC was superior to that of FSH with respect to histologic subtype (83% and 74%, respectively). Among histopathologically confirmed malignant tumors, the diagnostic accuracy of IC (62/64; 97%) was superior to that of FSH (58/64; 91%). The presence of necrosis and absence of adenoma cells were significantly more prevalent among malignant group than among borderline and benign groups (P < .01, for both).

CONCLUSION

Since the presence of necrosis and absence of adenoma cells around the carcinoma cells appear useful in distinguishing malignant and borderline tumors, it was proposed to include IC for further intraoperative assessment of any tumors initially diagnosed as a borderline tumor by FSH.

The approach of scratch-imprint cytology: Is it an alternative to frozen section for intraoperative assessment of pulmonary lesions?

To address the diagnostic performance of scratch-imprint cytology (SIC), in this study we compared intraoperative diagnoses of pulmonary lesions between SIC and frozen section histology (FSH) for accuracy with respect to the final pathological diagnosis. We histologically divided 206 pulmonary lesions (resected surgically) into two groups (benign and malignant) and compared each intraoperative diagnosis by SIC and FSH with the final pathological diagnoses. We also examined the radiological existence of pure ground-glass opacity (GGO) nodules in each group. The diagnostic sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 91.5%, 100%, 100%, 63.6%, and 92.6%, respectively for SIC, and 98.2%, 100%, 100%, 92.1% and 98.5%, respectively, for FSH. Thus, we concluded that diagnosis by SIC is reliable for malignancy, but not for benign lesions. All pure GGO nodules (19; 9.2%) were noninfectious and malignant with a high accuracy of FSH diagnosis (100%), in comparison with those of low accuracy with a SIC diagnosis (57.9%). SIC can be an appropriate intraoperative diagnostic tool where multiple cytotechnologists observe intraoperative SIC preparations scratched evenly across the whole lesion including the peripheral area of the mass.

A biosafety algorithm for the protection of pathology staff during intraoperative examinations of pulmonary lesions

We aimed to propose a biosafety algorithm for the protection of pathology staff during intraoperative examinations of pulmonary lesions when working with cytological imprints and/or frozen sections for the intraoperative diagnosis of pulmonary lesions. We examined 148 pulmonary surgical tissues obtained intraoperatively for imprint cytology (IC) and for frozen sectioning and compared the diagnoses against the final pathological diagnoses. We analyzed concordance and non-concordance rates and then used the data to produce a biosafety algorithm. The diagnostic sensitivity, specificity, positive predictive value, negative predictive value and accuracy of scratch-IC were 91%, 100%, 100%, 50% and 92%, respectively, and those of frozen sectioning were 99%, 100%, 100%, 96% and 99%, respectively. Our data indicate that frozen sectioning is unnecessary if scratch-IC yields a 'malignant' diagnosis but recommended with a 'benign' diagnosis. When a scratch-IC preparation deemed inadequate for a diagnosis or an abscess, the pathologist must consult the surgeon concerning the possibility of granuloma with caseous necrosis and should ask the surgeon to be prepared for a frozen section. If granuloma with caseous necrosis is found in the frozen section, the pathologist must immediately communicate the information to entire staff and perform a PCR test before making a permanent section.