Frozen Section of the Gastrointestinal Tract, Appendix, and Peritoneum

Diagnostic accuracy of frozen section biopsy for early gastric cancer extent during endoscopic submucosal dissection: a prospective study

BACKGROUND

Accurate diagnosis of the lateral extent of early gastric cancer during endoscopic submucosal dissection (ESD) is crucial to achieve negative resection margins. Similar to intraoperative consultation with a frozen section in surgery, rapid frozen section diagnosis with endoscopic forceps biopsy may be useful in assessing tumor margins during ESD. This study aimed to evaluate the diagnostic accuracy of frozen section biopsy.

METHODS

We prospectively enrolled 32 patients undergoing ESD for early gastric cancer. Biopsy samples for the frozen sections were randomly collected from fresh resected ESD specimens before formalin fixation. Two different pathologists independently diagnosed 130 frozen sections as "neoplasia," "negative for neoplasia," or "indefinite for neoplasia," and the frozen section diagnosis was compared with the final pathological results of the ESD specimens.

RESULTS

Among the 130 frozen sections, 35 were from cancerous areas, and 95 were from non-cancerous areas. The diagnostic accuracies of the frozen section biopsies by the two pathologists were 98.5 and 94.6%, respectively. Cohen's kappa coefficient of diagnoses by the two pathologists was 0.851 (95% confidence interval: 0.837-0.864). Incorrect diagnoses resulted from freezing artifacts, a small volume of tissue, inflammation, the presence of well-differentiated adenocarcinoma with mild nuclear atypia, and/or tissue damage during ESD.

CONCLUSIONS

Pathological diagnosis of frozen section biopsy is reliable and can be applied as a rapid frozen section diagnosis for evaluating the lateral margins of early gastric cancer during ESD.

Diagnostic challenges of intra-operative frozen consultation for gastrointestinal signet ring cell carcinoma†

AIMS

Signet ring cell carcinoma (SRCC) is challenging to recognise on intra-operative frozen sections, with known high false-negative rates. The objective of this study was to investigate common factors contributing to discrepancies between intra-operative frozen diagnoses and those made upon review of permanent sections, and summarise our experiences gained and lessons learned on minimising errors on intra-operative frozen diagnoses of gastrointestinal SRCC.

METHODS AND RESULTS

We retrospectively examined our pathology database from 25 May 2000 to 1 January 2018 and re-reviewed intra-operative frozen sections and permanent haematoxylin and eosin (H&E) slides for specimens confirmed with SRCC on permanent sections. This study includes 83 specimens taken from 50 patients, with an accuracy of 85.5%. Main common factors causing discordance or deferral in recognising SRCC between intra-operative frozen procedures and permanent sections include: (i) resemblance of clusters of SRCC cells with a myxoid background; (ii) disguise as normal or reactive cells (histiocytes, macrophages, large reactive lymphocytes, plasma cells or adipocytes) due to their relatively clear or depleted cytoplasmic mucin; and (iii) histological sampling errors, leading to misses of small foci of SRCC on frozen section slides.

CONCLUSIONS

An accurate diagnosis of SRCC during intra-operative frozen consultations remains challenging. Based on our experiences and lessons, the most important strategies to reduce diagnostic errors are: (i) understanding the unusual histomorphological features of SRCC cells on frozen sections including, but not limited to, intracellular mucin depletion, absence of desmoplasia and no adjacent pre-cancer changes; and (ii) close attention to abrupt transition from normal architecture (e.g. glandular or submucosal loose connective tissue) to myxoid and/or inflammatory-like appearance, which potentially harbours SRCC.

[Intraoperative rapid frozen section-when meaningful, when necessary?]

Intraoperative frozen sections can significantly improve the results of numerous visceral surgical operations. For this a close cooperation between surgery and pathology is a basic prerequisite. The main indications are the diagnostics of unclear intraoperative findings and the assessment of resection margins. Just as in any other procedure, there are also limiting factors to be considered in frozen section examinations.

Surgical Management of Primary Small Bowel NET Presenting Acutely with Obstruction or Perforation

Up to 35% of small bowel neuroendocrine tumors (SBNETs) may present with an acute intra-abdominal complication including obstruction, perforation, bleeding or ischemia and may require emergency surgical treatment in centers not normally accustomed to managing patients with neuroendocrine tumors. These patients may have a known diagnosis of SBNET, be suspected as suffering from SBNET or have SBNET diagnosed as an incidental finding on presenting radiology or postoperative pathology. Perioperative priorities include obtaining both clinical and radiological staging with cross-sectional imaging and clinical examination, screening for the presence of carcinoid syndrome and right-sided cardiac disease and assessment of prognosis. Intraoperatively careful attention should be paid to noting the presence and location of multifocal primary and metastatic disease. Ideally, surgical resection with mesenteric lymph node dissection is the treatment of choice for obstructing and perforating lesions. Extended lymphadenectomy along the SMA, SMV and behind the pancreas should be primarily considered an elective procedure. In unwell patients with advanced disease surgical bypass (jejuno or ileocolic) or proximal defunctioning should be undertaken but, given the excellent long-term survivals in patients with stage IV disease, could be considered bridging procedures to elective resection following formal staging and multidisciplinary review.

Frozen section diagnosis of gastrointestinal poorly cohesive and signet-ring cell adenocarcinoma: useful morphologic features to avoid misdiagnosis

Frozen section examination of adenocarcinomas with poorly cohesive growth, including signet-ring cell carcinoma, is challenging. Due to their diffuse morphology, the tumor cells may be indistinct and difficult to distinguish from inflammatory or stromal cells. Misdiagnosis may result in significant adverse clinical outcome. We performed a detailed retrospective analysis of such cases to identify features that are helpful to avoid misdiagnosis at the time of frozen section. We reviewed the original frozen section slides from 50 patients with poorly cohesive carcinoma (PCC) including 32 with positive and 18 with negative frozen section slides. Tumor cells and inflammatory cells were evaluated for 17 distinct cytologic and nine architectural or stromal features. Features with 100% specificity and positive predictive value (PPV) for carcinoma included the presence of cells with a single distinct cytoplasmic mucin vacuole, focal gland formation, and perineural invasion. Features with high specificity, sensitivity, PPV, and negative predictive value (NPV) (all > 75%) included irregular nuclear contours, large nuclear size with many nuclei > 4× the size of a small lymphocyte, and disruption/obliteration of normal structures. Other features with high specificity and PPV (both ≥ 85%) but relatively low sensitivity and NPV-included crescent-shaped/indented nuclei, prominent nucleoli, anisonucleosis (> 4:1 difference in nuclear size), multinucleation, and the presence of mitotic figures. We characterized useful histologic features of poorly cohesive carcinoma that may serve to distinguish carcinoma cells from benign inflammatory or stroma cells. Knowledge of the relatively specific features in particular may help surgical pathologists avoid false-negative interpretation resulting in significant clinical morbidity.

Laparoscopic Confocal Laser Microscopy Without Fluorescent Injection

Introduction. Histological analysis of surgical specimen is the gold standard for cancer classification. In particular, frozen histological diagnosis of vague peritoneal spots or uncertain excision of tumors plays a crucial role for proceeding with or without change of the operation procedure. Confocal laser microscopy (CLM) enables in vivo and real-time high-resolution tissue analysis. To evaluate a novel technique of CLM without any fluorescent dye, this pilot ex vivo study demonstrates a CLM camera device for minimal invasive surgical approach. Methods. In 5 cases, a laparoscopic CLM camera was used for examining colon and rectum specimen. Images of nonmalignant and malignant intestinal mucosa were characterized in terms of specific signal-patterns. No fluorescent dye was used. Correlations to findings in conventional histology were systematically recorded and described. Results. Using this CLM camera device, it is possible to analyze colon specimen mucosa. Nonmalignant and malignant intestinal mucosa show specific signal patterns. Nonmalignant mucosa is defined by honeycomb structure. There is deregulated structure in colon and rectum carcinoma mucosa. The inside lumen is irregular. The radial border appears swollen with reduced contrast. Discussion. This pilot study shows that the assessment of colon mucosa with a prototype of CLM camera for minimally invasive surgical approach without any fluorescent dye is feasible. It is possible to differentiate between benign and malignant mucosa in colon specimen by easy to evaluate and reproducible parameters. These first steps of this pioneering achievement to establish CLM in minimal invasive surgical procedures show a great potential for a more reliable intraoperative evaluation of suspect foci.

Diagnostic accuracy and utility of intraoperative microscopic margin analysis of gastric and esophageal adenocarcinoma

BACKGROUND

Positive resection margins are amongst the strongest predictors of cancer-related mortality for adenocarcinoma of the stomach and esophagus. Although intraoperative pathology consultation with frozen section of margins can predict final permanent section pathology, the accuracy of this approach is not known. We sought to determine the diagnostic accuracy of frozen section margin analysis in esophagogastric adenocarcinoma and the impact that it had on surgical therapy.

METHODS

Patients with resection of esophagogastric adenocarcinoma at a single centre from 1998 to 2008 were identified. Clinicopathologic data were collected. Frozen section results were compared to permanent section assessment, and sensitivity, specificity, positive, and negative predictive values were calculated. Patients with positive margins by frozen section were reviewed to assess the impact on surgical decision-making.

RESULTS

Of 220 patients who underwent surgery for adenocarcinoma of the esophagus and stomach (esophagus: 34/220, EGJ: 106/220, stomach 80/220), 56 % had an intraoperative consultation. Of these 122 patients, 66 % underwent frozen section. All errors on frozen section occurred on the interpretation of the proximal margin. The diagnostic accuracy of frozen section at the proximal margin was 93 % with sensitivity = 67 %, specificity = 100 %, positive predictive value = 100 %, and negative predictive value = 91 %. Signet ring cells were present in 83 % of false-negative readings. Surgical management was altered in 10 of the 13 of patients who had a true positive frozen section and 9 of these patients were converted to R0 resections.

CONCLUSIONS

Although very specific, negative results on frozen section require greater caution when signet ring cells are present. For esophagogastric adenocarcinoma, frozen section alters management and may increase the rate of complete resection.

Scatter spectroscopic imaging distinguishes between breast pathologies in tissues relevant to surgical margin assessment

PURPOSE

A new approach to spectroscopic imaging was developed to detect and discriminate microscopic pathologies in resected breast tissues; diagnostic performance of the prototype system was tested in 27 tissues procured during breast conservative surgery.

EXPERIMENTAL DESIGN

A custom-built, scanning in situ spectroscopy platform sampled broadband reflectance from a 150-μm-diameter spot over a 1 × 1 cm(2) field using a dark field geometry and telecentric lens; the system was designed to balance sensitivity to cellular morphology and imaging the inherent diversity within tissue subtypes. Nearly 300,000 broadband spectra were parameterized using light scattering models and spatially dependent spectral signatures were interpreted using a cooccurrence matrix representation of image texture.

RESULTS

Local scattering changes distinguished benign from malignant pathologies with 94% accuracy, 93% sensitivity, 95% specificity, and 93% positive and 95% negative predictive values using a threshold-based classifier. Texture and shape features were important to optimally discriminate benign from malignant tissues, including pixel-to-pixel correlation, contrast and homogeneity, and the shape features of fractal dimension and Euler number. Analysis of the region-based diagnostic performance showed that spectroscopic image features from 1 × 1 mm(2) areas were diagnostically discriminant and enabled quantification of within-class tissue heterogeneities.

CONCLUSIONS

Localized scatter-imaging signatures detected by the scanning spectroscopy platform readily distinguished benign from malignant pathologies in surgical tissues and showed new spectral-spatial signatures of clinical breast pathologies.

Intraoperative consultation in digestive surgery. A consecutive series of 800 frozen sections

AIM

To assess indications and quality of frozen sections in digestive surgery.

PATIENTS AND METHODS

All the frozen sections from the department of digestive surgery from Amiens hospital performed between 01/07/2006 and 01/07/2010 were assessed. Assessment of frozen section forms, reading of pathology reports, and reviewing of frozen section slides were performed.

RESULTS

Eight hundred frozen sections were performed in 349 patients. From one to 14 surgical specimens were sent for frozen section (mean 2.3). Frozen sections were performed in 77% of the cases for cancer surgery (n=268), most of the time pancreatic surgery (28.4%) and liver surgery (24.6%). Frozen sections were performed in 69% of the cases for diagnosis, in 29% of the cases to assess surgical margins and in 2% of the cases to assess if tissue specimen was appropriate for pathological diagnosis. Frozen sections were sent all days of the week (except Saturday and Sunday), during all the year, between 8 H 30 and 17 H 15. Thirty-seven percent of the cases were sent between 12 H and 14 H. Response time was 15 minutes (3 to 57 minutes). Rate of differed diagnoses was 2%. Rate of discordant diagnoses was 3.4%.

CONCLUSION

Frozen section is a rapid and accurate tool in digestive surgery. Local adjustment of the organization of the Pathology Department could enhance the rapidity and the quality of pathology diagnoses.

Endocrine tumors of the appendix: a pathologic review

CONTEXT

Although rare, appendiceal endocrine tumors are the most common neoplasms of the appendix. Pathologic analysis is important for guiding the management of patients.

OBJECTIVE

To provide recent data that focus on the pathology of endocrine tumors of the appendix including classifications and guidelines for patient management.

DATA SOURCES

A review of the recent literature including TNM classifications and patient management guidelines.

CONCLUSIONS

Appendiceal endocrine tumors are separated into 2 main groups: classic endocrine tumors and goblet cell carcinoids. They can be classified according to World Health Organization and TNM classifications. Evaluation of their prognoses and risks of malignancy, according to these classifications, depends on several parameters including tumor size, proliferation rate, and infiltration of appendiceal wall and mesoappendix. Most patients with classic endocrine tumors of the appendix have a favorable prognosis. Indications for postappendectomy, complementary surgery, which are still controversial, especially for tumors between 1 and 2 cm, are presented and discussed. In contrast, in patients presenting with a goblet cell carcinoid, a right hemicolectomy after the initial appendectomy is considered the standard surgical intervention.