The accuracy of intraoperative diagnoses based on examination of frozen sections. A prospective comparison with paraffin-embedded sections

Diagnosis, Prognosis, and Treatment of Canine Hemangiosarcoma: A Review Based on a Consensus Organized by the Brazilian Association of Veterinary Oncology, ABROVET

Hemangiosarcoma is a mesenchymal neoplasm originating in the endothelial cells of blood vessels; they can be classified as non-visceral and visceral types. Non-visceral hemangiosarcomas can affect the skin, subcutaneous tissues, and muscle tissues; visceral hemangiosarcomas can affect the spleen, liver, heart, lungs, kidneys, oral cavity, bones, bladder, uterus, tongue, and retroperitoneum. Among domestic species, dogs are most affected by cutaneous HSA. Cutaneous HSA represents approximately 14% of all HSA diagnosed in this species and less than 5% of dermal tumors, according to North American studies. However, Brazilian epidemiological data demonstrate a higher prevalence, which may represent 27 to 80% of all canine HSAs and 13.9% of all skin neoplasms diagnosed in this species. Cutaneous HSA most commonly affects middle-aged to elderly dogs (between 8 and 15 years old), with no gender predisposition for either the actinic or non-actinic forms. The higher prevalence of cutaneous HSA in some canine breeds is related to lower protection from solar radiation, as low skin pigmentation and hair coverage lead to greater sun exposure. Actinic changes, such as solar dermatosis, are frequent in these patients, confirming the influence of solar radiation on the development of this neoplasm. There are multiple clinical manifestations of hemangiosarcoma in canines. The diagnostic approach and staging classification of cutaneous HSAs are similar between the different subtypes. The definitive diagnosis is obtained through histopathological analysis of incisional or excisional biopsies. Cytology can be used as a presurgical screening test; however, it has little diagnostic utility in cases of HSA because there is a high risk of blood contamination and sample hemodilution. Surgery is generally the treatment of choice for dogs with localized non-visceral HSA without evidence of metastatic disease. Recently, electrochemotherapy (ECT) has emerged as an alternative therapy for the local ablative treatment of different neoplastic types; the use of radiotherapy for the treatment of dogs with cutaneous HSA is uncommon. There is greater consensus in the literature regarding the indications for adjuvant chemotherapy in subcutaneous and muscular HSA; doxorubicin is the most frequently used antineoplastic agent for subcutaneous and muscular subtypes and can be administered alone or in combination with other drugs. Other therapies include antiangiogenic therapy, photodynamic therapy, the association of chemotherapy with the metronomic dose, targeted therapies, and natural products. The benefits of these therapies are presented and discussed. In general, the prognosis of splenic and cardiac HSA is unfavorable. As a challenging neoplasm, studies of new protocols and treatment modalities are necessary to control this aggressive disease.

Diagnosis, Prognosis and Treatment of Canine Cutaneous and Subcutaneous Mast Cell Tumors

Mast cell tumors (MCTs) are hematopoietic neoplasms composed of mast cells. It is highly common in dogs and is extremely important in the veterinary oncology field. It represents the third most common tumor subtype, and is the most common malignant skin tumor in dogs, corresponding to 11% of skin cancer cases. The objective of this critical review was to present the report of the 2nd Consensus meeting on the Diagnosis, Prognosis, and Treatment of Canine Cutaneous and Subcutaneous Mast Cell Tumors, which was organized by the Brazilian Association of Veterinary Oncology (ABROVET) in August 2021. The most recent information on cutaneous and subcutaneous mast cell tumors in dogs is presented and discussed.

Diagnosing 12 prostate needle cores within an hour of biopsy via open-top light-sheet microscopy

SIGNIFICANCE

Processing and diagnosing a set of 12 prostate biopsies using conventional histology methods typically take at least one day. A rapid and accurate process performed while the patient is still on-site could significantly improve the patient's quality of life.

AIM

We develop and assess the feasibility of a one-hour-to-diagnosis (1Hr2Dx) method for processing and providing a preliminary diagnosis of a set of 12 prostate biopsies.

APPROACH

We developed a fluorescence staining, optical clearing, and 3D open-top light-sheet microscopy workflow to enable 12 prostate needle core biopsies to be processed and diagnosed within an hour of receipt. We analyzed 44 biopsies by the 1Hr2Dx method, which does not consume tissue. The biopsies were then processed for routine, slide-based 2D histology. Three pathologists independently evaluated the 3D 1Hr2Dx and 2D slide-based datasets in a blinded, randomized fashion. Turnaround times were recorded, and the accuracy of our method was compared with gold-standard slide-based histology.

RESULTS

The average turnaround time for tissue processing, imaging, and diagnosis was 44.5 min. The sensitivity and specificity of 1Hr2Dx in diagnosing cancer were both >90  %  .

CONCLUSIONS

The 1Hr2Dx method has the potential to improve patient care by providing an accurate preliminary diagnosis within an hour of biopsy.

There Is High Sensitive and Specific Correlation Between Frozen and Permanent Sections in Renal Transplant Biopsies

INTRODUCTION

Frozen sections have been used for evaluating tumors and margins during daily practice in pathology with high specificity and sensitivity (>90% for both indices both at national level and in our department). The correlation between frozen section tissue for immunofluorescent (IF) studies and permanent sections for light microscopy, along with electron microscopy, is critical for constructing a final renal pathology diagnosis.

METHODS

We studied the correlation between the frozen sections for IF studies and separate fragments of tissue for permanent light microscopic sections in our renal transplant biopsies for purposes of quality control. Frozen sections for IF sections were compared with permanent sections for light microscopy in 122 renal transplant biopsies, using inflammation as the key criterion (63 with no inflammation and 59 with inflammation) to determine the correlation.

RESULTS

There was high sensitivity (94.9%) and specificity (92.1%) for the correlation between the frozen section and permanent sections.

CONCLUSIONS

Our data suggest that parts of renal transplant biopsy tissue dissected to freeze for IF studies and for light microscopy were highly correlated to ensure a high quality of renal tissue dissection for the final diagnosis in renal transplant biopsies.

Rapid, quantitative reverse transcriptase-polymerase chain reaction: application to intraoperative molecular detection of occult metastases in esophageal cancer

OBJECTIVE

Our earlier data showed that quantitative reverse transcriptase-polymerase chain reaction can discriminate patients with node-negative cancer who are at high risk for recurrence. The objective of this study was to determine whether a new, more rapid quantitative reverse transcriptase-polymerase chain reaction assay could provide this information in a time frame suitable for intraoperative decision making.

METHODS

We studied formalin-fixed, archived lymph nodes from 30 patients with histologically determined node-negative esophageal cancer with rapid quantitative reverse transcriptase-polymerase chain reaction to measure expression of carcinoembryonic antigen messenger RNA. We also performed rapid quantitative reverse transcriptase-polymerase chain reaction on 37 snap-frozen lymph nodes from 23 patients. Eleven of the 23 patients had benign esophageal disorders (negative control group). The other 12 had esophageal cancer, 6 with histologically determined positive lymph nodes and 6 with histologically determined negative lymph nodes.

RESULTS

In the retrospective analysis of archival tissue from 30 patients with esophageal cancer with histologically determined negative lymph nodes, rapid quantitative reverse transcriptase-polymerase chain reaction predicted disease recurrence with a sensitivity and a specificity of 90% and 80%, respectively, and was comparable to conventional quantitative reverse transcriptase-polymerase chain reaction. In the frozen-tissue analysis rapid quantitative reverse transcriptase-polymerase chain reaction detected significantly higher levels of carcinoembryonic antigen expression in all 12 of the histologically determined positive lymph nodes than in the benign nodes. For 2 of these 12 nodes the intraoperative frozen-section analysis had negative histologic results, and N1 status was determined only on final pathologic examination. Rapid (intraoperative) quantitative reverse transcriptase-polymerase chain reaction discriminated both nodes as positive. Among the 14 histologically determined negative nodes, 1 of 3 nodes from 1 patient showed increased carcinoembryonic antigen according to rapid quantitative reverse transcriptase-polymerase chain reaction, and this patient had a clinical recurrence.

CONCLUSIONS

In our study we were able to rapidly discriminate patients with node negative-esophageal cancer who had a high risk of recurrence. In frozen tissues rapid quantitative reverse transcriptase-polymerase chain reaction correlated with final pathologic report for 11 of 12 patients. In the 1 discordant case, the quantitative reverse transcriptase-polymerase chain reaction result was positive and may have detected microscopically occult metastasis, because this patient did have disease recurrence. Rapid quantitative reverse transcriptase-polymerase chain reaction was more sensitive than intraoperative frozen sections for detecting metastatic disease. These data suggest that rapid quantitative reverse transcriptase-polymerase chain reaction may have a prognostic role and could guide intraoperative decisions.

Evaluation of rapid staining techniques for cytologic diagnosis of intracranial lesions

OBJECTIVE

To evaluate 4 rapid supravital stains and 3 preparation techniques for use in the intraoperative diagnosis of intracranial lesions.

ANIMALS

10 dogs and 1 cat euthanatized for intracranial lesions.

PROCEDURE

Specimens were taken from lesions and slides prepared, using 3 techniques: touch impression, medium-pressure impression, or smear preparation. Preparations were then stained with 4 stains: modified Wright stain, May-Grünwald-Giemsa, toluidine blue, and zynostain and examined in a blinded randomized fashion. Cytologic diagnosis was compared with histopathologic diagnosis and classified on the basis of identification of the pathologic process and specific diagnosis into the following categories: complete correlation, partial correlation, or no correlation.

RESULTS

An overall diagnostic accuracy of 81% (107/132) was achieved on the basis of a combination of partial and complete correlation. Of the stains examined, modified Wright stain appeared to be most accurate, with complete correlation in 17 of 33 (52%) specimens and partial correlation in 12 of 33 (36%) specimens. Of the preparation methods, touch preparation and smear preparation provided the most accurate results, with an overall diagnostic accuracy of 82% (36/44) for both methods. However, smear preparations appeared to be of greater diagnostic value, with fewer nondiagnostic specimens, compared with touch preparations.

CONCLUSIONS AND CLINICAL RELEVANCE

Cytologic preparations provide a useful diagnostic tool for the intraoperative diagnosis of intracranial lesions. All stains examined yielded promising results, the most accurate of which appeared to be the modified Wright stain. The smear preparation appeared to be the preparation method of greatest diagnostic value.

Use of pelvic flexure biopsies to predict survival after large colon torsion in horses

OBJECTIVE

To determine if morphologic evaluation of intraoperative biopsies of the large colon could be used to accurately predict outcome in horses with large colon torsion.

STUDY DESIGN

Clinical study.

ANIMALS

Fifty-four horses with large colon torsion.

METHODS

A full-thickness biopsy was collected from the pelvic flexure of the ascending colon after correction of naturally occurring colonic torsion. Morphologic changes were evaluated and graded for interstitial tissue to crypt ratio (I:C ratio), percentage loss of superficial and glandular epithelium, and the degree of hemorrhage and edema. These variables were then used to predict survival.

RESULTS

Morphologic variables could be used to correctly predict survival or death in 51 horses (P < .0001). This corresponded to a sensitivity of 95.1% (82.2%-99.2%; 95% CI) and a specificity of 92.3% (62.0%-99.6%; 95% CI). Of 6 horses that had colonic resection, 5 survived; an accurate prediction of outcome based on morphologic criteria was made for each horse.

CONCLUSIONS

Interpretation of changes in colonic morphology can be used to accurately predict postoperative survival in horses with large colon torsion.

CLINICAL RELEVANCE

Use of frozen colonic tissue sections is a rapid, reliable, and relatively inexpensive method for assessing morphologic damage associated with large colon torsion during surgery. Intraoperative evaluation of pelvic flexure biopsies can aid in the prediction of survival and guide surgical judgment as to the need for colonic resection.

Pathological fracture of the femur secondary to haematogenous osteomyelitis in a weimaraner

A seven-year-old male weimaraner developed an acute-onset non-weightbearing pelvic limb lameness without a history of significant trauma. Radiographs demonstrated an oblique fracture of the femur associated with a lytic bone lesion, while cytology and histopathology of the lesion were consistent with osteomyelitis. A pure growth of Streptococcus intermedius was obtained from culture of affected tissue samples. The fracture healed without complication after rigid internal fixation and antibiotic therapy.

Principles of oncologic abdominal surgery

The principles of abdominal oncologic surgery parallel the general principles of all types of oncologic surgery with some variations peculiar to the abdomen. Due to the presence of multiple organ systems within the abdominal cavity, many types of cancer can develop. The surgeon must be prepared to perform several different abdominal procedures depending on the organ system involved and the extent of the cancer. The surgeon as oncologist must be aware of the tumor type, its expected behavior, and current treatment options. This article describes the principles of performing cancer surgery, including preparation for abdominal exploration, methods to facilitate tumor removal, and ways of avoiding tumor recurrence.

Principles of tumor biopsy

Tumor biopsy is the cornerstone of sound therapeutic decision making in oncology. Although there are multiple ways to obtain a biopsy from any given tumor, each individual procedure requires careful planning to ensure that the optimal treatment course is not compromised. Knowledge of the principles and techniques underlying biopsy is imperative to ensure an accurate diagnosis with minimal morbidity. This article describes the principles of biopsy and commonly used sampling techniques and where these procedures are most applicable. Appropriate tissue handling, interpretation of results, and some special techniques are also described.

Principles of reconstructive surgery for the tumor patient

Small animal oncologic surgery is a relatively new and rapidly expanding field of veterinary science. Many exciting and innovative techniques for surgical resection of invasive tumors have been developed and published in the last decade. Paralleling these developments have been major advancements in the frontiers of reconstructive options to close the defects after major ablative surgery. A more thorough understanding of the biologic behavior of tumors in our patients has permitted us to rationally approach selected patients with high doses of surgery with curative intent, palliation, or as part of a multimodality treatment plan. Invasive oncologic procedures require thorough preoperative planning and staging to accomplish the goal of tumor-free margins. Patient factors, specifically tumor type, grade, anatomic location, and extent of local invasion, will subsequently dictate the appropriate resection and reconstructive options available. Resection of the tumor with a wide margin of normal tissue is the surgeon's primary objective. The reconstructive phase of the surgery endeavors to restore functional and cosmetic integrity to the regional anatomy. Each resection and reconstruction procedure must be customized for the patient's disease. Thoughtful preoperative planning, timing, and intraoperative flexibility to unforeseen circumstances will minimize complications. Armed with a number of reconstructive options for each case, the surgeon develops intraoperative flexibility and latitude to be more aggressive during the primary resection. If the surgeon self-imposes limitations on the aggressive removal of the primary tumor by virtue of tissue closure concerns, the completeness of resection and patient survival may well be jeopardized. As familiarity and experience with different reconstructive options increases, the surgeon will have greater confidence in removing large volumes of diseased tissue.

Partial cystectomy for urinary bladder neoplasia: surgical technique and outcome in 11 dogs

Partial cystectomy was performed in 11 dogs with bladder neoplasia (10 with transitional cell carcinoma and one with rhabdomyosarcoma). Between 40 and 70 per cent of the bladder was excised during the partial cystectomies. In eight dogs, all the grossly visible tumour was excised but on histopathological examination of the excised tissue, neoplastic tissue was found to extend to the surgical margins in four of these dogs. A ureteral stoma was excised with the tumour in four dogs necessitating ureteral reimplantation; one dog had both ureteral stomas excised and bilateral ureteral reimplantation. The bladder incision dehisced in two dogs, necessitating a second surgery. Six dogs were pollakiuric after surgery. Pollakiuria resolved within two months in four dogs and persisted in two dogs. None was incontinent. Local tumour recurrence was suspected in nine dogs based on imaging studies and confirmed in five dogs during post mortem examination. Five dogs were euthanased two to seven months after surgery. Six dogs survived at least one year, two of these dogs remain alive at 17 and 27 months after surgery. It is concluded that partial cystectomy may provide local control of bladder neoplasia.

Efficacy of frozen-section evaluation of uterine curettings in the diagnosis of ectopic pregnancy

OBJECTIVE

This study was undertaken to examine the accuracy of frozen section for the identification of products of conception on curettage of patients undergoing surgery for suspected ectopic pregnancy.

STUDY DESIGN

A retrospective analysis of 87 consecutive cases in which frozen-section assessment of an endometrial curettage specimen to identify products of conception was undertaken. A frozen-section diagnosis was considered correct if the final diagnosis concurred with the findings at frozen section.

RESULTS

Eighty-one of 87 (93.1%) specimens were correctly identified at frozen section. Frozen section had a sensitivity of 78.3% and a specificity of 98.4%. The positive predictive value of frozen section in this population was 94.7% and the negative predictive value was 92.6%. No significant correlation was found regarding the attending pathologist at frozen section, preoperative human chorionic gonadotropin, or time of day at frozen section.

CONCLUSIONS

Frozen section is accurate for the identification of products of conception on endometrial curettage in the evaluation of a suspected ectopic pregnancy.