Utilization of frozen sections in the evaluation of chronic epilepsy–related cases

The role of frozen section consultation in the evaluation of chronic epilepsy–associated surgical excisions of brain tissue has not been previously examined. The study retrospectively reviews 335 cases in which a frozen section consultation was obtained in the setting of a resection for chronic epilepsy. In most cases (n = 323), 3 or fewer frozen sections were performed. The most commonly identified pathologies on final diagnosis included tumor or tumorlike lesions (79.1% of cases) and focal cortical dysplasia (20.9% of cases). Frozen section diagnoses discrepant with final diagnoses due to sampling error or misinterpretation were noted in 39 cases and most commonly involved a diagnosis of gliosis or tumor in the setting of a focal cortical dysplasia or diagnosis of gliosis in the setting of a low-grade tumor. In conclusion, frozen section consultation may be particularly useful in the evaluation of neoplasms arising in the setting of chronic epilepsy. Some epilepsy-associated pathology, such as focal cortical dysplasia, may be difficult to diagnose at the time of frozen section and such cases may not be an ideal target for intraoperative frozen section consultation.     

Intraoperative consultation for nervous system lesions

The pathologist responsible for nervous system intraoperative consultations must know basics of the clinical history, details of the location and imaging characteristics of the lesion, and must be familiar with known clinicopathologic entities. Although cytologic and frozen section techniques have not changed significantly in the past 15 years, significant advancements in neuroimaging have greatly improved the ability to generate an accurate preoperative differential diagnosis. Such information can greatly aid the pathologist during intraoperative consultation. This review concerns the intraoperative cytologic and frozen section findings of the major clinicopathologic entities encountered in surgical neuropathology. While neoplastic processes of the central nervous system will be emphasized, important non-neoplastic conditions that mimic brain tumors will also be covered. A basic clinicopathologic approach to successful neurosurgical intra-operative consultation is provided.     

Bedeutung der Schnellschnittdiagnostik für das Management laryngealer Tumoren

The frozen section procedure for immediate intraoperative pathological diagnosis represents a pivotal method in tumor diagnosis. In laryngeal tumors the most frequent indication for the use of this method is the documentation of the residual tumor status, while intraoperative consultation with the purpose of primary tumor diagnosis is less common. The specimen management employed in each case should be chosen depending on the clinical question: while the collection of a maximum amount of tissue is advisable for the determination of the residual tumor status, sparing a portion of the remaining tissue for possible future examinations is advisable in the case of primary tumor diagnosis. Moreover, intraoperative frozen section diagnosis with no immediate consequences should be avoided.     

Use and abuse of frozen section in the diagnosis of follicular thyroid lesions

The role of intraoperative frozen section in certain organ systems such as the thyroid continues to be problematic. In many cases, diagnoses are deferred or nonhelpful—“follicular lesion.” In the modern era, the widespread use of preoperative aspiration biopsy has allowed for more careful selection of patients who undergo thyroid surgery. In many cases, the fine-needle-aspiration (FNA) biopsy diagnosis can be definitive or can guide the specific surgical procedure. The literature supports our approach, which is summarized as follows: Intraoperative consultation is not needed on the intrathyroidal nodule if a preoperative FNA was definitive for papillary carcinoma. Frozen section is of no value in the intraoperative diagnosis of lesions diagnosed on FNA as “follicular neoplasm” or “Hürthle cell neoplasm” because the characterization of these lesions requires detailed analysis of the tumor capsule for the demonstration of capsular and/or vascular invasion—an analysis that is not practical in the intraoperative setting. Finally, intraoperative consultation including frozen section and intraoperative cytologic examination is most useful in those cases that are diagnosed as suspicious for papillary carcinoma by FNA, because the assessment of nuclear features needed for the definitive diagnosis is possible with intraoperative techniques in a significant number of cases.     

Use of robotic telepathology for frozen-section diagnosis: a retrospective trial of a telepathology system for intraoperative consultation.

Telepathology is the practice of digitizing histological or macroscopic images for transmission along telecommunication pathways for diagnosis, consultation, or continuing medical education. Previous studies have addressed static versus dynamic imaging in several specimen types with a wide variety of systems and communication pathways. The goal of this paper was to assess the validity of a Web-based telepathology system for frozen section consultation within the Army Medical Department. The system provides real-time, dynamic remote control of a robotic microscope over standard Internet connections. Oftentimes, a solo pathologist is called on to provide diagnostic services without the support of immediate second or expert consultation during an intraoperative consultation. The use of telepathology is attractive because it provides an opportunity for pathologists to obtain immediate consultation. For purposes of the study, 120 consecutive frozen section cases were diagnosed at a distance using the system. Intraobserver agreement between the telepathology diagnosis and glass slide diagnosis was observed. Diagnostic agreement was 100% for a wide variety of specimens. This study suggests that such a system will help support pathologists located at distant sites.     

Intraoperative consultation in gynecologic pathology

Intraoperative consultation is widely used in gynecologic surgical practice to make intraoperative diagnosis, primarily to aid the surgeon to plan the extent of surgery. This article reviews the indications, performance and interpretation, accuracy and diagnostic pitfalls in the three major areas of gynecologic malignancies where intraoperative consultations are most frequently requested: ovarian masses, endometrial carcinoma and carcinoma of the cervix. For ovarian masses intraoperative consultation is usually requested either for histologic confirmation of malignant or borderline primary ovarian tumors before proceeding with radical surgery, or to rule out malignancy at the time of surgery for presumed benign disease. The diagnosis of endometrial carcinoma is usually made preoperatively before definitive surgical treatment. Thus, intraoperative consultation is most often used to identify the subgroup of patients with features of high risk disease who have an increased risk of metastases and who will benefit from formal surgical staging. In cases of carcinoma of the cervix frozen section is most commonly used to estimate the extent of spread of known invasive carcinoma at the time of radical surgery. Despite its restrictions, frozen section diagnosis is an important and reliable tool in the clinical management of patients with ovarian, endometrial and cervical tumors. The specificity of the method in experienced hands is high, the sensitivity is sufficient. The diagnosis of borderline ovarian tumors may be troublesome however, mainly due to their heterogeneity in appearance, especially in the case of large tumors of mucinous histologic type. It is important for pathologists to have a clear idea of the role and limitations of frozen section diagnosis in gynecological surgery in order to play a meaningful and optimal role in the management of the gynecologic oncology patient.     

Role of cytology and frozen sections in the intraoperative examination of the thyroid: comparison of two experiences

Two experiences of peroperative diagnosis in thyroid surgery are reported. In Bordeaux (France), frozen sections are supplemented by touch smears. Imprints alone give results similar to frozen but are not suitable in differentiating follicular adenoma from carcinoma; they appear more accurate for recognising the follicular presentation of papillary carcinoma. Touch smear is a rapid cost-effective alternative to frozen section. In Brussels (Belgium), a more conventional attitude results in 185 frozen. A false negative ends in a follicular carcinoma. Eleven follicular proliferations will be signed out adenoma (8 cases) or carcinoma (3 cases) and three papillary carcinomas will only be detected after embedding. Six false negative derive from frozen section, no false positive is noted. An immediate change in the surgical procedure is justified twice. These observations argue for the free choice by the pathologist of the best technical procedure in peroperative diagnosis.     

Fine-needle aspiration and intraoperative consultation in thyroid pathology: when and how?

Fine-needle aspiration (FNA) and frozen section evaluation are traditional components of the management of thyroid lesions. Their role and usefulness are dictated by some basic facts about thyroid pathology: (a) nodules are very common; (b ) they are benign in the majority of cases; and (c) the diagnosis of malignancy is primarily based on cytologic features in the case of papillary carcinoma, and on the presence of invasion of the tumor capsule or of blood vessels in the case of follicular carcinoma. The common occurrence of benign thyroid nodules mandates a cost-effective effective method for preoperative screening. Since, as already stated, the diagnosis of papillary thyroid carcinoma (by far the most common thyroid malignancy) is based on the identification of characteristic cytologic features, FNA has easily emerged in the past 30 years as the most accurate and cost-effective tool-indeed a true cornerstone-for the preoperative management of thyroid nodules. Standardized terminology to report cytologic diagnoses is highly recommended and is being implemented worldwide. Conversely, the importance of intraoperative frozen section diagnosis has been constantly decreasing over the past years, as a direct consequence of the widespread application of FNA. It may, however, be very useful in cases that are suspicious for papillary carcinoma on FNA and in selected cases with an indeterminate cytologic diagnosis.     

A retrospective analysis of the diagnostic accuracy and technical quality of frozen sections in detecting hepatobiliary lesions

IntroductionPathological consultation on intraoperative frozen sections plays a crucial role in the management of patients undergoing surgical therapy, and is also a key indicator for quality assurance in anatomical pathology. This study aimed to evaluate the diagnostic accuracy and technical quality of frozen sections in detecting hepatobiliary lesions with malignant potential.Patients and methodsA retrospective database review was performed for 1208 cases intraoperative pathology consultation who underwent hepatobiliary lesions resection at our institution from 2016 to 2020. The intraoperative consultation cases during a 5-year period were reviewed and analyzed, including the measurement of the diagnostic accuracy and turnaround time of frozen sections, the reasons for discrepancies, and the rates of discordance and deferral.ResultsIn this study, we confirmed that the overall accuracy, sensitivity and specificity were 95.3 %, 96.3 % and 96.6 %, respectively, in distinguishing benign from malignant lesions. The rates of deferred and discordant diagnoses were 2.57 % and 2.2 %, respectively. The overall frozen section turnaround time was 22.1 min. The most common cause of deferred and discordant was poor section quality, the lesion of bile duct margin on the frozen section, misinterpretation of difficult and complicated cases, etc.ConclusionsThis study confirms that the intraoperative frozen sections can serve as a rapid, accurate and robust method for the pathological diagnosis of suspected hepatobiliary lesions. However, it should be noted that some poor technical problems, pathological assessment of tumor margin and difficult cases are the most frequently causes of deferred and discordant interpretations.     

Intraoperative consultation of ovarian neoplasms.

A review of 313 intraoperative consultations and/or frozen section evaluations of neoplasms of the ovary was conducted. The intraoperative diagnosis of benign or malignant was compared with the diagnosis found at permanent section. Only six cases were deferred to permanent section. The overall accuracy was 93.9%. The sensitivity was 72.7%, and this was explained by the high proportion of borderline or low malignant cell tumors in this series. The specificity and predictive values were in excess of 95%. Thirteen cases were diagnosed incorrectly at intraoperative consultation. Eight of these were judged to be sampling errors, one was due to poor technical quality, and four were attributed to interpretation errors. Intraoperative consultation is, and should continue to be, a valuable tool in the evaluation of ovarian neoplasms.     

Approach to the intraoperative consultation for neurosurgical specimens

Intraoperative consultation remains an invaluable tool in the initial evaluation of surgically excised specimens. Good communication is required between the pathologist and surgeon to obtain the best care for their mutual patient. Intraoperative consultation (frozen section, FS) provides a preliminary diagnosis for the surgeon and aids in guiding his/her subsequent surgical approach. For the pathologist, it serves to assess tissue adequacy in the context of the clinical and imaging features of the patient. FS can guarantee that the surgeon is in the desired anatomic location, but most often serves to ensure that adequate amounts of abnormal, and likely diagnostic, tissue will be available to the pathologist to render a final diagnosis on permanent sections. The preliminary evaluation of tissue at the time of intraoperative FS also guides the pathologist in the ordering of ancillary studies, some of which need to be performed on fresh or frozen tissues and must be sent at the time of the intraoperative consultation. This brief review will specifically focus on the role of the pathologist who is called to perform a FS for a neurosurgical specimen. We will discuss (1) the goals of the neurosurgeon for the intraoperative consultation, (2) how to achieve optimal communication between neurosurgeon and pathologist at the time of the FS, (3) what constitutes reasonable and unreasonable expectations by the neurosurgeon for the FS, (4) choices of techniques that can be used by the pathologist, (5) what tissue should be triaged, and (6) common discrepancies between FS and permanent section diagnoses in central nervous system disorders. The published literature on FS and permanent section discrepancies will be briefly reviewed so that pathologists will understand that some difficulties are inherent in neurosurgical specimens and are not specific to their practice, or to a given pathologist. Hopefully, this knowledge will enhance pathologists' confidence as they negotiate how best to handle this time-sensitive, and sometimes angst-producing, task.     

Pancreatic frozen section nightmares

Pancreatic resections have steadily increased over the past few decades and as a consequence so have the number of pancreatic specimens submitted for intraoperative frozen section consultation. Frozen section evaluation of the pancreas is generally performed for tumour confirmation and the assessment of margin status. An accurate and prompt diagnosis is therefore critical in guiding surgical management. However, pancreatic frozen sections are among the most challenging specimens submitted to the pathologist. While the main diagnostic dilemma is between adenocarcinoma and chronic pancreatitis, the spectrum of reactive changes, preinvasive neoplasms, neoadjuvant treatment effect and incidental lesions can further confound this assessment. The purpose of this review is to briefly discuss practical guidelines in specimen handling, common tissue artifacts, non-neoplastic and neoplastic frozen section histology, and challenging scenarios. In addition, it is our hope that this review will serve to facilitate better communication between the surgeon and pathologist to enhance patient care.     

Intraoperative consultation for renal lesions. Implications and diagnostic pitfalls in 324 cases

Intraoperative consultation rarely is requested for lesions in the kidney. Of 324 renal lesions submitted for gross or frozen section intraoperative consultation, 199 specimens were submitted for gross consultation only; no diagnostic pitfalls were noted. The clinical implications and diagnostic pitfalls in 125 specimens submitted for frozen section were the focus of our study. Frozen section intraoperative consultation was requested to evaluate surgical margins in partial nephrectomy specimens, solid renal mass in an unusual clinical or radiologic setting, synchronous renal and extrarenal masses, cystic renal lesion, ureteral surgical margins for transitional cell carcinoma, multiple renal masses, solid mass in a diffusely cystic kidney, and renal injury. Among the 125 cases, the diagnoses were deferred in 17 (6 renal cell carcinomas with granular cytoplasm, 7 cystic lesions, 3 metastatic tumors, 1 leiomyoma). The frozen section diagnoses were incorrect owing to limited sampling in 5 and misinterpretation in 4 (melanoma vs angiomyolipoma, lymphoma vs angiomyolipoma, benign cyst vs cystic renal cell carcinoma, metastatic renal cell carcinoma vs pheochromocytoma). Awareness of distinctive indications for frozen section intraoperative consultation and diagnostic pitfalls should improve diagnostic accuracy and facilitate proper management of these lesions.     

Correlation of fine needle aspiration cytology and frozen section biopsies in the diagnosis of thyroid nodules.

AIMS: To evaluate the correlation of fine needle aspiration (FNA) cytology and frozen section biopsy in the diagnosis of thyroid nodules. METHODS: The medical records of 662 patients who underwent FNA cytology of the thyroid and thyroid surgery were analysed. Frozen section biopsies were taken from 586 of the 662 patients. The diagnostic correlations of FNA cytology, frozen section, and both FNA cytology and frozen section with definitive histological assessment were evaluated. RESULTS: Among the 662 patients who received FNA cytology, there were 356 cases (53.8%) diagnosed as benign, 114 cases (17.2%) as malignant, 148 cases (22.4%) as indeterminate, and 44 cases (6.6%) as unsatisfactory. The positive predictive value for the detection of malignancy by FNA cytology was 92.1% and the negative predictive value was 95.2%. The incidence of malignancy in the indeterminate cytological diagnosis was 23%. The diagnosis from frozen sections was benign in 445 cases (75.9%), malignant in 134 cases (22.9%), and deferred in 7 cases (1.2%). By frozen section, the positive and negative predictive values were 97% and 95.5%, respectively. Diagnostic accuracy up to 98% was achieved when FNA cytology and frozen section diagnoses were in agreement. No false positives were observed when FNA cytology and frozen sections were both positive for malignancy. When FNA cytology and frozen section diagnoses were discordant, frozen section showed a higher accuracy (78.9%) than FNA cytology (21.1%). In the face of an indeterminate or unsatisfactory cytological diagnosis, the diagnostic accuracy of frozen sections reached 92.6%. CONCLUSIONS: The results confirm that FNA cytology is a useful tool in the initial evaluation of thyroid nodules. Intraoperative frozen section is a valuable procedure to confirm the cytological diagnosis and identify malignancy in patients with indeterminate or unsatisfactory cytological diagnosis. With reliance on frozen sections as an intraoperative guide of thyroid surgery, the possibility of unnecessary extensive surgery and the need for the second operation are considerably lower.     

Pleomorphic adenoma of the human female breast.

We are presenting an interesting rare benign breast tumor which meets the characteristics of a salivary gland pleomorphic adenoma. The tumor was misdiagnosed during frozen section procedure, because several clusters, mainly composed of myoepithelial cells and surrounded by a chondroid matrix, were mistaken for cancerous blasts. Additionally the clinical and mammographic findings were very suspicious. Although this particular tumor is very infrequent, the pathologist should be aware of the difficulties in the differential diagnosis during frozen section and thus defer his final answer to the paraffin sections.     

Application of domestic microwave for urgent histopathology reporting: an evaluation

Rapid diagnosis of histopathological material is becoming increasingly desirable. In neuropathology, crush smear preparation and frozen section diagnosis of tissues removed during operative procedures, have remained as essential tools for rapid diagnosis. Microwave technology has been introduced into the field of tissue processing and staining in past decade. Now-a-days even automated microwave assisted rapid tissue processors are available. In our study we have analysed the use of a domestic microwave (cost approximately Rs.5000) for urgent histoprocessing (30 minutes). This could be useful in small laboratories or the ones which are in the phase of establishing the department as the procedure is much more economical than obtaining a frozen section (which requires a cryostat worth 3-6 lakhs) and the interpretation of the section obtained does not require any extra experience as these resemble the routinely processed tissue sections. The advantages and limitations of the procedure have been discussed.     

Crush preparations of meningiomas: Can grading be accomplished?

Crush preparations (CP) for the diagnosis of meningioma are routinely performed in the frozen section suite when tissue is submitted for intraoperative consultation. The goal of this study was to examine the cytologic features of meningiomas in CP and evaluate if benign meningioma (Grade 1), atypical meningioma (Grade 2), and malignant meningioma (Grade 3) can be diagnosed on CP. All cases of meningioma (1999-2007), which were submitted for frozen section at our institution, were retrospectively reviewed. These cases were examined intraoperatively by frozen section and CP. The final histologic diagnosis was taken as the gold standard. A total of 107 meningiomas cases were reviewed. The cytological features of all these cases were studied, and features such as pleomorphism, hemorrhage, necrosis, mitosis, and presence or absence of nucleoli were recorded. Using the final histopathologic diagnosis as the gold standard, there were 72 (Grade 1), 22 (Grade 2), and 13 (Grade 3) meningioma cases, which were studied. In conclusion, this study reviews the salient cytologic features of Grades 1-3 meningiomas. It demonstrates that it is difficult to separate Grade 1 from Grade-2 meningioma on CP, and last, Grade-3 meningioma can be easily diagnosed on CP.     

Schnellschnittdiagnostik in der Osteopathologie

Bone tumors are very rare and this is the reason why frozen section diagnosis is often difficult. The orthopedic surgeon wants to know the intraoperative diagnosis of biopsies of benign or malignant bone tumors so that definitive treatment can be carried out immediately in cases of diagnostic certainty. Diagnostic problems not only concern the distinction of benign and malignant tumors but also differentiation of a neoplastic from a reactive process. Clinical information is very important and all patients with bone tumors are discussed before surgical treatment in an interdisciplinary tumor board. Internationally but with the exception of the USA, the diagnostic procedure using frozen sections is not commonly used even in specialized centers.     

Accuracy of frozen section diagnosis in soft tissue tumors

This study was undertaken to analyze the accuracy of frozen section (FS) diagnosis of 118 soft tissue tumors with respect to the reasons for which the intraoperative consultation was indicated. Fifty-seven frozen sections were performed for the diagnosis of an unknown pathologic process. Complete agreement was established in 40.3% and the correct pathologic process in 43.9%, the diagnosis was deferred in 14%, and the remaining 1.8% were diagnosed incorrectly. Examination for determination of the adequacy of resection margin (22 cases), lymph node or skip metastases (23 cases), residual or recurrent tumor after previous surgery (29 cases), viable tumor tissue after previous locoregional or systemic therapy (ten cases), and identification of the specimen (five cases) proved to be 95.5%, 95.7%, 96.6%, 90%, and 100% accurate. Considering the whole series, an erroneous answer to a question posed by a surgeon was given in four cases (two false positive and two false negative), of which two cases were a sampling error made by pathologist. Intraoperative consultation by FS in soft tissue tumors is (a) reliable for general rather than exact diagnosis in defining the previously unknown pathologic process and (b) mandatory in evaluating resection margins and any discrepancies between preoperative cytologic and intraoperative gross impression.     

Interinstitutional comparison of frozen section consultation in small hospitals: a College of American Pathologists Q-Probes study of 18,532 frozen section consultation diagnoses in 233 small hospitals

OBJECTIVE: To study pathology intraoperative consultation practices and the accuracy of diagnoses made by frozen section. DESIGN: In 1994, participants in the College of American Pathologists Q-Probes laboratory quality improvement program each completed questionnaires and prospectively collected data on up to 20 frozen section procedures performed over a 5-month period. SETTING: Surgical pathology laboratories serving private and public hospitals with 300 or fewer occupied beds. PARTICIPANTS: Two hundred thirty-two North American institutions and one New Zealand institution. MAIN OUTCOME MEASURES: The discordance and deferral rates of frozen section diagnoses and the reasons for frozen section discordance relative to corresponding diagnoses made on permanent (paraffin) sections. Calculation of frozen section discordance rates excluded diagnoses of subtypes or grade of malignancy, biopsies on specimens in which there was no gross lesion (eg, mammographic specimens), thyroid follicular lesions, tissue taken only to determine adequacy for other studies (eg, estrogen-binding proteins), and frozen sections performed to evaluate margins of specimens oriented en face. RESULTS: Out of 18,532 frozen section diagnoses performed on 327,884 surgical cases, 859 (4.6%) diagnoses were deferred until permanent sections were available for review; 17,357 (98.2%) nondeferred diagnoses agreed with, and 316 (1.8%) disagreed with, those diagnoses rendered on permanent sections. The most common cause of discordance was underdiagnosis of neoplasia, usually due to block- or tissue-sampling errors. CONCLUSIONS: We recommend that laboratories routinely monitor frozen section discordance, cut additional sections deeper into the frozen block and/or sample additional tissue when the initial frozen section diagnosis is negative or nonproductive, reconcile all discordant frozen section diagnoses in the final report, and periodically assess the value of performing frozen section examinations.