Comparison of staining quality between rapid and routine hematoxylin and eosin staining of frozen breast tissue sections: an observational study.

OBJECTIVE: To compare the staining quality between rapid hematoxylin and eosin (H&E) staining and routine H&E staining of frozen breast tissue sections. METHODS: In this cross-sectional observational study, 120 frozen breast tissue sections were randomly assigned to rapid or routine H&E staining (n = 60 per group). Rapid H&E staining used a 7:1 mixture of modified Gill's hematoxylin and alcohol-soluble 1% eosin Y. The staining quality of each section was evaluated and scored. A score of >7 was considered excellent, a score of 6 to 7 good, and a score of ≤5 poor. RESULTS: The staining time for rapid staining was approximately 3 minutes, whereas that of routine staining was approximately 12 minutes. There were no significant differences in the staining quality scores or proportions of sections in each grade between the two staining methods. The proportions of sections that were classified as excellent or good were 96.7% and 98.3% for rapid and routine staining, respectively. CONCLUSIONS: In frozen breast tissue sections, rapid H&E staining may provide staining quality that is comparable to that of routine staining, while markedly reducing the staining time.

Immunofluorescence staining of chloroplast proteins with frozen sections of plant tissues.

KEY MESSAGE: Immunofluorescence staining with frozen sections of plant tissues and a nest tube is convenient and effective, and broadens the applicability of immunofluorescence staining. Immunofluorescence staining is an indispensable and extensively employed technique for determining the subcellular localization of chloroplast division proteins. At present, it is difficult to effectively observe the localization of target proteins in leaves that are hard, or very thin, or have epidermal hair or glands with the current immunofluorescence staining methods. Moreover, signals of target proteins were predominantly detected in mesophyll cells, not the cells of other types. Thus, the method of immunofluorescence staining was further explored for improvement in this study. The plant tissue was embedded with 50% PEG4000 at -60℃, which was then cut into sections by a cryomacrotome. The sections were immediately immersed in fixation solution. Then, the sample was transferred into a special nested plastic tube, which facilitated the fixation and immunofluorescence staining procedures. The use of frozen sections in this method enabled a short processing time and reduced material requirements. By optimizing the thickness of the sections, a large proportion of the cells could be well stained. With this method, we observed the localization of a chloroplast division protein FtsZ1 in the wild-type Arabidopsis and various chloroplast division mutants. Meanwhile, the localization of FtsZ1 was also observed not only in mesophyll cells, but also in guard cells and epidermal cells in a lot of other plant species, including many species with hard leaf tissues. This method is not only easy to use, but also expands the scope of applicability for immunofluorescence staining.

A multicenter proof-of-concept study on deep learning-based intraoperative discrimination of primary central nervous system lymphoma.

Accurate intraoperative differentiation of primary central nervous system lymphoma (PCNSL) remains pivotal in guiding neurosurgical decisions. However, distinguishing PCNSL from other lesions, notably glioma, through frozen sections challenges pathologists. Here we sought to develop and validate a deep learning model capable of precisely distinguishing PCNSL from non-PCNSL lesions, especially glioma, using hematoxylin and eosin (H&E)-stained frozen whole-slide images. Also, we compared its performance against pathologists of varying expertise. Additionally, a human-machine fusion approach integrated both model and pathologic diagnostics. In external cohorts, LGNet achieved AUROCs of 0.965 and 0.972 in distinguishing PCNSL from glioma and AUROCs of 0.981 and 0.993 in differentiating PCNSL from non-PCNSL lesions. Outperforming several pathologists, LGNet significantly improved diagnostic performance, further augmented to some extent by fusion approach. LGNet's proficiency in frozen section analysis and its synergy with pathologists indicate its valuable role in intraoperative diagnosis, particularly in discriminating PCNSL from glioma, alongside other lesions.

Effect of Different Staining Methods on Brain Cryosections.

Staining frozen sections is often required to distinguish cell types for spatial transcriptomic studies of the brain. The impact of the staining methods on the RNA integrity of the cells becomes one of the limitations of spatial transcriptome technology with microdissection. However, there is a lack of systematic comparisons of different staining modalities for the pretreatment of frozen sections of brain tissue as well as their effects on transcriptome sequencing results. In this study, four different staining methods were analyzed for their effect on RNA integrity in frozen sections of brain tissue. Subsequently, differences in RNA quality in frozen sections under different staining conditions and their impact on transcriptome sequencing results were assessed by RNA-seq. As one of the most commonly used methods for staining pathological sections, HE staining seriously affects the RNA quality of frozen sections of brain tissue. In contrast, the homemade cresyl violet staining method developed in this study has the advantages of short staining time, low cost, and less RNA degradation. The homemade cresyl violet staining proposed in this study can be applied instead of HE staining as an advance staining step for transcriptome studies in frozen sections of brain tissue. In the future, this staining method may be suitable for wide application in brain-related studies of frozen tissue sections. Moreover, it is expected to become a routine step for staining cells before sampling in brain science.

Variation of resection margins in oral cancer in dependence of tumor stage and subsite - a retrospective cohort study.

OBJECTIVES: Surgical resection is a key component of the treatment of head and neck cancer and the achievement of free surgical margins are essential for the patients' outcome in terms of survival. While there is a general recommendation for a free resection range of 5 mm, up to date, there is a lack of investigations on the quality of tumor resection in dependence of affected subsite and tumor stage. In the presented study, predictors for the achieved resection margins in surgically treated oral squamous cell carcinomas were analyzed. MATERIALS AND METHODS: A cohort of 567 patients was included in a retrospective analysis and resection status with exact margin ranges were analysed. Tumor stage, affected subsite and the results of the intraoperative frozen section analysis were assessed. Primary endpoint was the achieved resection margin in mm, secondary endpoints were overall and progression-free survival. RESULTS: The observed mean values of minimal resection margins differed significantly between the investigated subsites (p = 0.042),pathological tumor stages (p < 0.001) and in tumors which demonstrated perineural infiltration (Pn1, p = 0.002). Furthermore, there was a significant impact of the results of the intraoperative frozen section analysis on progression-free and overall survival (p < 0.001). CONCLUSIONS: Our data clearly indicate that resection status differs between tumors of different subsites and tumor stages. CLINICAL RELEVANCE: Clinical procedures should be adapted in order to achieve similar certainty in all resections, and, thus to improve patients' outcome.

Feasibility of intraoperative pathologic examination for sentinel lymph nodes during sentinel node navigation surgery in early gastric cancer: results of pathologic protocol for SENORITA trial.

BACKGROUND: During sentinel node navigation surgery in patients with gastric cancer, intraoperative pathologic examination of sentinel nodes is crucial in determining the extent of surgery. In this study, we evaluated the feasibility and accuracy of intraoperative pathologic protocols using data from a prospective, multicenter, randomized trial. METHODS: A retrospective analysis was conducted using data from the SEntinel Node ORIented Tailored Approach trials from 2013 to 2016. All sentinel lymph nodes were evaluated during surgery with hematoxylin-eosin (HE) staining using a representative section at the largest plane for lymph nodes. For permanent histologic evaluation, sentinel basin nodes were stained with HE and cytokeratin immunohistochemistry in formalin-fixed, paraffin-embedded (FFPE) sections and examined with HE for three deeper-step sections at 200-µm intervals. The failure rate of identification by frozen section and the metastasis rate in non-sentinel basins were investigated. RESULTS: Of the 237 patients who underwent sentinel node basin dissection, 30 had lymph node metastases on permanent pathology. Thirteen patients had macrometastasis confirmed in frozen sections as well as FFPE sections (failure rate: 0%). Patients with negative sentinel nodes in frozen sections but micrometastasis in FFPE sections had no lymph node recurrence during the follow-up period (0%, 0/6). However, in cases with tumor-positive nodes in frozen sections, metastases in non-sentinel basins were detected in the paraffin blocks (8.3%, 2/24). CONCLUSIONS: The single-section HE staining method is sufficient for detecting macrometastasis via intraoperative pathological examination. If a negative frozen-section result is confirmed, sentinel basin dissection can be performed safely. Otherwise, standard surgery is required.

Prediction of lymph node metastasis in patients with papillary thyroid cancer based on radiomics analysis and intraoperative frozen section analysis: A retrospective study.

INTRODUCTION: To evaluate the diagnostic efficiency among the clinical model, the radiomics model and the nomogram that combined radiomics features, frozen section (FS) analysis and clinical characteristics for the prediction of lymph node (LN) metastasis in patients with papillary thyroid cancer (PTC). METHODS: A total of 208 patients were randomly divided into two groups randomly with a proportion of 7:3 for the training groups (n = 146) and the validation groups (n = 62). The Least Absolute Shrinkage and Selection Operator (LASSO) regression was used for the selection of radiomics features extracted from ultrasound (US) images. Univariate and multivariate logistic analyses were used to select predictors associated with the status of LN. The clinical model, radiomics model and nomogram were subsequently established by logistic regression machine learning. The area under the curve (AUC), sensitivity and specificity were used to evaluate the diagnostic performance of the different models. The Delong test was used to compare the AUC of the three models. RESULTS: Multivariate analysis indicated that age, size group, Adler grade, ACR score and the psammoma body group were independent predictors of lymph node metastasis (LNM). The results showed that in both the training and validation groups, the nomogram showed better performance than the clinical model, albeit not statistically significant (p > .05), and significantly outperformed the radiomics model (p < .05). However, the nomogram exhibits a slight improvement in sensitivity that could reduce the incidence of false negatives. CONCLUSION: We propose that the nomogram holds substantial promise as an effective tool for predicting LNM in patients with PTC.

Comparison of Intraoperative Imprint Cytology versus Frozen Section for Sentinel Lymph Node Evaluation in Breast Cancer. A study along with Systematic Review and Meta-analysis of literature.

BACKGROUND: Sentinel lymph node (SLN) is the first lymph node to drain the lymph from a particular region involved by cancer. The commonly performed intraoperative methods for SLN evaluation are touch imprint cytology (TIC) and frozen section (FS). The present study aimed to determine the sensitivity, specificity and accuracy of TIC and FS with histopathological diagnosis as gold standard. MATERIALS AND METHODS: The nodes were bissected along their long axis and wet surface was imprinted on to clean glass slides followed by toluidine blue and rapid Papanicolaou staining. Subsequently the lymph node slices were cut at three levels using the cryostat machine and stained with Hematoxylin and eosin stain. The cytological and FS findings were compared and the specificity, sensitivity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of TIC and FS was evaluated taking histopathological diagnosis as gold standard. In addition, pooled sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy for touch imprint cytology and frozen section were assessed for the studies included in the meta-analysis. RESULTS: The specificity, sensitivity, diagnostic accuracy, positive predictive value and negative predictive value of touch imprint cytology were 100%, 88.2%, 90%, 100% and 60% respectively. The specificity, sensitivity, diagnostic accuracy, PPV and NPV of frozen section were 100%, 94.1%, 95%, 100% and 75% respectively. The sensitivity of TIC and FS for detection of micrometastasis was 60% and 80% respectively. The pooled sensitivity and specificity for touch imprint cytology were 85.24% (95% CI, 83.46%-86.90%), and 98.99% (95% CI, 98.69%-99.23%) respectively. The pooled sensitivity and specificity for frozen section examination were 90.45% (95% CI, 85.15%-94.34%), and 100% (95% CI, 99.24%-100%) respectively. CONCLUSION: Even though the sensitivity of FS was better than imprint cytology in detection of micrometastasis, TIC is a rapid inexpensive technique which can be utilized in remote areas in absence of cryostat machine. The sensitivity of the two techniques with respect to detection of macrometastasis was comparable. This meta-analysis highlights the accuracy of the touch imprint cytology and frozen section examination in the intra-operative detection of malignancy in breast cancer.

Intraoperative frozen section of subareolar tissue in nipple-sparing mastectomy: Towards a less is more approach.

BACKGROUND: Nipple preservation contributes to aesthetic outcome and quality of life in women undergoing Skin-Sparing Mastectomy (SSM) with immediate breast reconstruction for the treatment of breast cancer. Intraoperative Frozen Section (IFS) has been advocated to facilitate conversion from Nipple-Sparing Mastectomy (NSM) to SSM in cases with positive subareolar margins. This study investigated the application of IFS at our comprehensive cancer centre. METHODS: In this single-centre retrospective study, for all patients who underwent therapeutic NSM with IFS from 2000 to 2021 pathological reports, patient- and tumour characteristics were retrieved. RESULTS: In total 640 women were included in whom 662 intended NSMs with IFS had been performed. Sensitivity and specificity of frozen section compared with definitive histopathology were 75.2% and 98.5% respectively. In six women with a false positive result, the nipple had been removed. In 16 out of 32 women with a false negative result, the nipple was excised in a second procedure. In total 115 nipples were resected. In 40% of these nipples, no residual disease was detected. DISCUSSION: IFS is a moderately sensitive and highly specific diagnostic tool to detect positive subareolar margins. An alternative approach is to omit frozen section but take intraoperative biopsies of the sub areolar margin, which are postoperatively analysed with definitive formalin-fixed paraffin-embedded histopathology. This allows for shared decision making regarding nipple excision in cases where minimal disease is found in subareolar tissue or cases with an indication for post-mastectomy radiotherapy.

Does the use of intraoperative frozen section of bone marrow from the cut end of the mandible help assess the adequacy of bone margins following mandibulectomy for oral cancer?

BACKGROUND: The adequacy of the cut end of the mandible following a segmental mandibulectomy done for oral cancer intraoperatively is at times assessed using a frozen section (FS) of the bone marrow (BM) at the cut ends. The study aimed to assess its utility to guide the intraoperative decision on the adequacy of bony margins. MATERIALS AND METHODS: All patients with oral squamous cell carcinoma (OSCC) who underwent segmental mandibulectomy from January 2012 to December 2021 at our institute and for whom intraoperative FS of BM was utilized were included. We analyzed the sensitivity, specificity, and positive and negative predictive value (PPV, NPV) of this in predicting positive bone margins. RESULTS: A total of 457 patients were included in the study. The majority of the cases were per premium cases (n = 372, 81.4%). The median age of the cohort was 52 years (range: 22-80 years). Most patients had T4 disease (n = 406, 88.8%). On FS, BM was positive in only 18 patients (3.9%) for whom the bone margin was revised. BM biopsy report in the final histopathology was positive in 12 patients (2.2%). The sensitivity, specificity PPV, and NPV were 52.3%, 98.65%, 64.7%, and 97.7% respectively. No factors predicting BM positivity on FS could be identified in this cohort. CONCLUSIONS: The BM FS was positive in only a small percentage of patients, and it helped in reducing the bone margin positivity rate from 3.9% to 2.2% only. Hence the intraoperative BM FS seems to have limited utility as seen from our study.

Challenging pitfalls in frozen section pathology: a case of mandible ghost cell odontogenic carcinoma and the literature review.

BACKGROUND: Ghost cell odontogenic carcinoma (GCOC) is a rare malignancy characterized by the presence of ghost cells, preferably in the maxilla. Only slightly more than 50 case reports of GCOC have been documented to date. Due to the rarity of this tumor and its nonspecific clinical criteria, there is a heightened risk of misdiagnosis in clinical examination, imaging findings, and pathology interpretation. CASE PRESENTATION: A 50-year-old male patient presented to the hospital due to experiencing pain in his lower front teeth while eating for the past 2 months. Upon examination, a red, hard, painless mass was found in his left lower jaw, measuring approximately 4.0 cm × 3.5 cm. Based on the malignant histological morphology of the tumor and the abundant red-stained keratinized material, the preoperative frozen section pathology misdiagnosed it as squamous cell carcinoma (SCC). The surgical resection specimen pathology via paraffin section revealed that the tumor was characterized by round-like epithelial islands within the fibrous interstitium, accompanied by a large number of ghost cells and some dysplastic dentin with infiltrative growth. The malignant components displayed marked heterogeneity and mitotic activity. Additionally, a calcified cystic tumor component of odontogenic origin was observed. Hemorrhage, necrosis, and calcifications were present, with a foreign body reaction around ghost cells. Immunoreactivity for ß-catenin showed strong nuclear positivity in tumor cells, while immunostaining was completely negative for p53. The Ki67 proliferation index was approximately 30-40%. The tumor cells exhibited diffuse CK5/6, p63, and p40 immunoreactivity, with varying immunopositivity for EMA. Furthermore, no BRAFV600E mutation was identified by ARMS-PCR. The final pathology confirmed that the tumor was a mandible GCOC. CONCLUSION: We have reported and summarized for the first time the specific manifestations of GCOC in frozen section pathology and possible pitfalls in misdiagnosis. We also reviewed and summarized the etiology, pathological features, molecular characteristics, differential diagnosis, imaging features, and current main treatment options for GCOC. Due to its rarity, the diagnosis and treatment of this disease still face certain challenges. A correct understanding of the pathological morphology of GCOC, distinguishing the ghost cells and the secondary stromal reaction around them, is crucial for reducing misdiagnosis rates.

Intraoperative frozen section pathology of vaginal margin in radical hysterectomy on the prognosis and quality of life for patients with IB2-IIA2 cervical cancer: study protocol for a multicenter randomized controlled trial.

BACKGROUND: Several risk factors have been identified that compromise the treatment outcome in patients with early-to-mid-stage cervical cancer (CC) who are primarily treated with radical surgery. However, there is no report on the impact of intraoperative frozen pathology examination of vaginal margins on the prognosis of patients with CC. This study aimed to conduct a randomized controlled trial (RCT) to determine whether selective vaginal resection can reduce the incidence of operative complications and the risk of postoperative radiotherapy. The impact of the length of the vagina removed in radical hysterectomy (RH) on prognosis and quality of life (QoL) for IB2-IIA2 CC patients will be investigated. METHODS: A multicenter, non-inferiority, RCT at 7 institutions in China is designed to investigate the effect of intraoperative frozen pathology exam of vaginal margin in RH on the survival outcomes for patients with IB2-IIA2 CC. Eligible patients aged 18-70 years will be randomly assigned online by one-to-one random allocation to receive intraoperative frozen pathology exam of vaginal margin or not. If frozen pathology indicates positive margin, continue resection of 1 centimeter of vaginal tissue until negative margin is achieved. The primary end point is 2-year disease-free survival (DFS). Adverse events (AEs) caused by further vagina resection, 5-year DFS, 2-year overall survival (OS), 5-year OS and AEs caused by radiotherapy and QoL are secondary end points. A total of 310 patients will be enrolled from 7 tertiary hospitals in China within 3-year period and followed up for 5 years. TRIAL REGISTRATION: Chinese Clinical Trial Registry Identifier: ChiCTR2000035668.

Optimizing Ideal Thickness of Sections for Epidermis in Intra-Operative Frozen Sections.

AIM AND OBJECTIVES: To estimate and evaluate the optimal thickness of tissue section for skin and dermal appendages intra-operatively and to compare the morphology and architecture of the epidermis and its appendages at 7 and 10 microns. METHODOLOGY: After obtaining clearance from the institutional human ethical committee, 101 skin margins were prospectively analyzed using a two-step embedding technique. After multiple trials and errors, 7- and 10-micron thicknesses were selected for the present study. Artefacts, staining characteristics, cellular morphology, cellular outline, and nuclear outline were assessed and scored as unacceptable or acceptable. The data were entered in a Microsoft Excel spreadsheet and analyzed using SPSS software. RESULTS: There was a statistically significant difference between the sections obtained at 7 microns and 10 microns (p-value: <0.001), the latter were better in all the parameters analyzed. However, no difference was noted in the characteristics of the dermal appendages (p-value: >0.05). CONCLUSION: While mucosal margins can be obtained at the usual 5-7 microns, the same thickness is not optimal for skin margins intra-operatively. Frozen sections for the skin margins may be set at 10 microns, to save time, minimize artefacts, and for better readability.

Using Initial Biopsies and Vertical Sections to Improve Trainees' Confidence in Performing Mohs Surgery.

BACKGROUND: Tissue preservation and tumor clearance are hallmarks of Mohs micrographic surgery, but no standardized method currently exists to guide trainees on how to balance the two. OBJECTIVE: The authors provided residents and fellows with additional histologic information to enhance their surgical decision-making without changing the standard methodology of Mohs surgery. METHODS AND MATERIALS: Trainees were provided initial biopsy slides (IS) and frozen vertical sections (VS) of the first Mohs layer. All Mohs layers were excised in standard fashion, and vertically oriented sections were taken from the layer without disturbing the surgical margins to obtain VS. Surveys were used to assess trainees' confidence in performing Mohs surgery with and without these tools. RESULTS: Trainees reported increased confidence in performing Mohs surgery when they reviewed IS before surgery and viewed VS of the first layer. CONCLUSION: Reviewing IS and VS improved trainees' confidence in performing Mohs surgery. This additional histological information was obtained while maintaining the usual steps of Mohs surgery. Objective information obtained from IS and VS may explain why trainees' confidence increased using this technique. Both IS and VS can be valuable teaching tools that may enhance trainees' ability to perform Mohs surgery.

[Fluorescence confocal microscopy-complete digitization of pathology]. / Fluoreszenzbasierte Konfokalmikroskopie ­ vollständige Digitalisierung der Pathologie.

BACKGROUND: Fluorescence-based confocal microscopy (FCM) can be used to create virtual H&E sections in real time. So far, FCM has been used in dermato-, uro-, and gynecopathology. FCM allows the creation of a completely digitized frozen section, which could potentially replace conventional frozen sections in the future. OBJECTIVE: The aim of the current work is to implement FCM technology as a component of fully digitized processes in the pathological workflow. For this purpose, the current use of FCM in liver transplant pathology will be extended to other disciplines such as urology and otorhinolaryngology. MATERIALS AND METHODS: The FCM technique continues to be used prospectively on native tissue samples from potential donor livers. Conventional frozen sections are used comparatively to virtual FCM scans. RESULTS: The data show a nearly perfect agreement for the detection of cholangitis, fibrosis, and malignancy, and a high level of agreement for, e.g., macrovesicular steatosis, inflammation, steatohepatitis, and necrosis between virtual FCM scans and conventional routine diagnostic frozen sections. CONCLUSION: Since the availability of time- and cost-intensive frozen section diagnostics in the context of transplant pathology in continuous operation (24/7) is now only established at very few university centers in Germany due to an increasing shortage of specialists, the use of FCM could be an important building block in the current process leading towards a fully digitized pathology workflow and should thus be extended to various disciplines.

Diagnostic accuracy of intraoperative frozen section for margin evaluation of oral cavity squamous cell carcinoma.

OBJECTIVES: Intraoperative frozen-section evaluation is a valuable technique for detecting positive margins intraoperatively for oral squamous cell carcinoma. We conducted this study to determine the diagnostic accuracy of frozen section in detecting margin status and the effect of tumor grade and stage on diagnostic accuracy. RESULTS: A total of 251 biopsy-proven cases of oral squamous cell carcinoma were included in this study. The tissue specimen resected during surgery was sent to the laboratory for frozen section evaluation. The frozen section results were then compared with the permanent section results to determine the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy. The mean age of the patients included in the study was 51.65 ± 10.03 years, with male predominance (55.4%). The overall sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of frozen section were 88.81%, 94.84%, 95.20%, 88.10%, and 91.63%, respectively. We conclude that frozen section is a useful technique in determining the margin status intraoperatively in oral cancers, with high diagnostic accuracy. Moreover, certain clinical parameters such as age, gender, disease duration, and tumor stage and grade appear to affect the diagnostic accuracy of frozen section.

Neurosarcoidosis: Frozen section rescue for a big mimicker - A case report.

Neurosarcoidosis is an uncommon but potentially serious manifestation of sarcoidosis. Diagnosis may be particularly challenging especially when neurosarcoidosis occurs in isolation or is the initial presentation of the systemic disease. The authors take this opportunity to report a case of neurosarcoidosis, presenting as the first manifestation of the disease, diagnosed on frozen section, occurring in a 43-year-old male patient with no past history or manifestation of sarcoidosis.

Fluorescence Assisted Stereotactic Biopsy of Contrast-Enhancing Brain Lesions: Can YELLOW 560-nm Filter Substitute Frozen Section?

BACKGROUND: The factors on which the accuracy of stereotactic brain biopsy depends are the competence of the neurosurgeon in obtaining a representative sample and the ability of the neuropathologist to make a histological diagnosis from a minuscule sample. Over the years intraoperative frozen section has enhanced the diagnostic yield of this minimally invasive procedure. Use of fluorescence in achieving a greater extent of resection is well-established in contemporary neurosurgical practice. This ability of brain tumors to take up the fluorescein sodium dye and glow under the YELLOW 560-nm filter has been utilized in a handful of studies to increase the diagnostic accuracy of stereotactic biopsy. METHODS: We performed a prospective study where the fluorescein sodium dye was injected at a low dose and fluorescence of the biopsied core was compared with that of a tissue obtained from the normal parenchyma. Sample was labeled 'truly fluorescent' only when the glow was more than that of the tissue from normal parenchyma. RESULTS: On cross-tabulating the index test (true fluorescence status) and the reference standard test (final histopathological report) the sensitivity of acquiring a representative sample was found to be 94.74%, specificity was 100%. The positive predictive value and negative predictive value were calculated to be 100% and 50% respectively. The diagnostic yield was comparable to that of the intraoperative frozen section. CONCLUSION: The use of the YELLOW 560-nm filter can make stereotactic biopsy faster, safer, less cumbersome, and more cost-effective, and can be used as a substitute for the frozen section in resource-constrained centers.