Use of frozen section in genitourinary pathology

Intraoperative pathology consultation during urological surgery: Impact on final margin status and pitfalls of frozen section diagnosis

Despite recent improvements in diagnostic and surgical techniques in urological oncology, positive resection margin remains a significant concern for surgeons. Meanwhile, intraoperative pathology consultation with frozen section assessment (FSA), particularly for histological diagnosis of the lesions incidentally found or enlarged or sentinel lymph nodes, generally provides critical information which enables immediate decision making for optimal patient care. The intraoperative evaluation of surgical margins is also often requested, although there are some differences in its application between institutions and surgeons. Importantly, it remains to be determined whether intraoperative FSA indeed contributes to reducing the risk of final positive margins and thereby improving long-term patient outcomes. This review summarizes available data indicating the potential impact of FSA at the surgical margins during urological surgeries, including radical or partial cystectomy, partial nephrectomy, radical prostatectomy, penectomy, and orchiectomy. The accuracy and pitfalls of the intraoperative consultation/FSA diagnosis are also discussed.

The impact of routine frozen section analysis during partial cystectomy for bladder cancer on surgical margin status and long-term oncologic outcome

OBJECTIVES

The utility of frozen section analysis (FSA) during partial cystectomy has not been established. We assessed the impact of intraoperative FSA in partial cystectomy cases on surgical margin (SM) status and patient outcome.

SUBJECTS AND METHODS

A retrospective review identified 76 consecutive patients who underwent partial cystectomy for bladder carcinoma with (n = 66; 87%) or without (n = 10; 13%) FSA for SMs at our institution from 2004 to 2018. FSA was correlated with the diagnosis of the frozen section control, the status of final SM, and the prognosis.

RESULTS

Final SM was positive in 9 (12%) cystectomies, including 6 (9%) FSA vs. 3 (30%) non-FSA cases (P = 0.091). There were no significant differences in tumor size, histology, or tumor grade/stage between the 2 cohorts. FSAs were reported as positive (n = 7; 11%), atypical (n = 10; 15%), and negative (n = 49; 74%). All of the positive and negative FSA diagnoses were confirmed accurate on the frozen section controls, whereas atypical diagnoses were revised to benign (n = 4), atypical (n = 4), and carcinoma (n = 2) on the controls. Ten (77%) of 13 initial FSA-positive (6 of 7)/atypical (4 of 6; excluding benign diagnoses on the controls) cases achieved negative conversion by excision of additional tissue. Thus, final SM was positive in 1 (14%) FSA-positive case, 3 (30%) FSA-atypical cases (including one at the SM where FSA was not sampled), and 2 (4%) FSA-negative cases (at the SM where FSA was not sampled). Kaplan-Meier analysis and log-rank test revealed an association of performing FSA with the risk of disease progression (P = 0.021), but not intravesical recurrence (P = 0.434) or cancer-specific mortality (P = 0.560). Initial positive/atypical FSA, as an independent prognosticator, was associated with reduced progression-free (P = 0.002) and cancer-specific (P = 0.004) survival rates, compared with initial negative FSA. Positive SM was also associated with a larger tumor size (P < 0.05) and a higher risk of intravesical recurrence (P = 0.070) or disease progression (P = 0.096).

CONCLUSIONS

Performing FSA during partial cystectomy may contribute to preventing positive SM and disease progression. Additionally, as seen in most of initial FSA-positive/atypical cases that achieved negative conversion, select patients may benefit from the routine FSA. Meanwhile, positive or atypical FSA was associated with significantly poorer prognosis.

Reliability of Frozen Section Examination in a Large Cohort of Testicular Masses: What Did We Learn?

BACKGROUND

Frozen section examination (FSE) for testicular masses is gaining popularity because of the possibility of performing testis-sparing surgery (TSS) on the basis of the FSE results. The aim of our study was to investigate the reliability of FSE in the diagnosis of testicular masses.

PATIENTS AND METHODS

From 1999 to 2016, 144 of 692 patients who underwent surgery in our tertiary center for testicular masses had FSE. The indications for FSE were: masses < 1 cm, nonpalpable, multiple, or with unusual presentation. Mean follow-up for patients was 25.5 months. The algorithm of surgery determined by FSE was: orchiectomy if malignant or nonconclusive pathology; TSS if benign or nontumor pathology. FSE data were analyzed retrospectively. Specificity and sensitivity of the method was calculated for benign, malignant, seminoma, and nonseminoma tumors.

RESULTS

Intraoperative FSE was conducted on 21% of candidates for surgery on testicular masses. The sensitivity and specificity of FSE were 93% and 98%, respectively, for malignant tumors, and 90% and 99%, respectively, for benign tumors. The κ agreement coefficient between FSE and final histopathology was statistically significant (0.76). TSS was performed in 57 (40%) patients, including 6 of 23 monorchid patients.

CONCLUSION

FSE correlates well with final histopathological diagnosis of testicular masses. Thus, it reliably identifies patients who might benefit from TSS. FSE should be considered always in small, nonpalpable, multiple, or uncommonly presenting masses in solitary testis or both testes.

Clinical benefits of frozen section assessment during urological surgery: Does it contribute to improving surgical margin status and patient outcomes as previously thought?

Despite significant advances in patient selection as well as surgical technique over the past few decades, it is still not uncommon for patients with urological malignancy and positive surgical margins to be observed. Meanwhile, intraoperative pathology consultation with frozen section assessment, which generally provides useful information for the optimal procedure, has been widely utilized for the assessment of surgical margins during urological surgeries. Thus, it remains unanswered whether intraoperative frozen section assessment has an impact on final surgical margin status as well as long-term oncological outcomes. The present review summarizes and discusses available data assessing the utility of frozen section assessment of the surgical margins during urological surgeries, such as radical prostatectomy, partial nephrectomy and radical cystectomy. The current findings suggest that select patients might benefit from the routine frozen section assessment.

Frozen section: guiding the hands of surgeons?

Frozen section (FS) analysis is a powerful tool that can provide a rapid diagnosis, directing operative management. However, FSs can also be misused. We consider an FS to be "inappropriate" when it does not influence operative management or immediate patient care. Not only can inappropriate FSs compromise diagnostic material, they can impact turnaround time of other FSs. We evaluated the utilization of FSs at our institution and assessed influence on intraoperative management. Frozen sections performed at the University of Alabama at Birmingham Hospital in 2013 were stratified by surgical subspecialty. Operative, clinical, and pathology notes were reviewed to determine the rationale for sending each FS and to determine impact on intraoperative management. Cases lacking operative notes were excluded. A total of 4104 FSs were performed in 1896 cases. Surgical subspecialties included cardiothoracic, otolaryngology, breast, surgical oncology, gynecology, gastrointestinal, hepatobiliary, urology, transplant, and orthopedics. 42.5% of FSs evaluated margin status, 34.8% confirmed or excluded malignancy, 9.5% were for tumor classification, 6.7% assessed adequacy for diagnosis, 1.9% were to confirm or exclude infection, 2.8% were for transplant, and 1.8% were for lymphoma workup. Twelve percent (491/4104) of FSs did not influence operative management. This was most common among cardiothoracic surgeries (34%). No inappropriate FSs were sent for any transplant surgeries. Otolaryngology used the most FSs and had less than 1% that were inappropriate. Most FSs influence operative management. The rationale for sending an FS and its influence on operative management was subspecialty dependent. Interdepartmental discussions of FS utilization might be helpful in the elimination of unnecessary FSs.

Histostitcher™: An informatics software platform for reconstructing whole-mount prostate histology using the extensible imaging platform framework

CONTEXT

Co-registration of ex-vivo histologic images with pre-operative imaging (e.g., magnetic resonance imaging [MRI]) can be used to align and map disease extent, and to identify quantitative imaging signatures. However, ex-vivo histology images are frequently sectioned into quarters prior to imaging.

AIMS

This work presents Histostitcher™, a software system designed to create a pseudo whole mount histology section (WMHS) from a stitching of four individual histology quadrant images.

MATERIALS AND METHODS

Histostitcher™ uses user-identified fiducials on the boundary of two quadrants to stitch such quadrants. An original prototype of Histostitcher™ was designed using the Matlab programming languages. However, clinical use was limited due to slow performance, computer memory constraints and an inefficient workflow. The latest version was created using the extensible imaging platform (XIP™) architecture in the C++ programming language. A fast, graphics processor unit renderer was designed to intelligently cache the visible parts of the histology quadrants and the workflow was significantly improved to allow modifying existing fiducials, fast transformations of the quadrants and saving/loading sessions.

RESULTS

The new stitching platform yielded significantly more efficient workflow and reconstruction than the previous prototype. It was tested on a traditional desktop computer, a Windows 8 Surface Pro table device and a 27 inch multi-touch display, with little performance difference between the different devices.

CONCLUSIONS

Histostitcher™ is a fast, efficient framework for reconstructing pseudo WMHS from individually imaged quadrants. The highly modular XIP™ framework was used to develop an intuitive interface and future work will entail mapping the disease extent from the pseudo WMHS onto pre-operative MRI.