Rapid Immunohistochemistry With Thyroid Transcription Factor-1 for Pulmonary Adenocarcinoma

Rapid Immunohistochemistry Based on Ultrasonic Thermal Steam Heating for Improvement of Intraoperative Diagnosis

OBJECTIVES

To evaluate the role of rapid immunohistochemistry (RIHC) based on ultrasonic thermal steam heating in improving diagnostic accuracy of intraoperative frozen section diagnosis and to recommend RIHC antibody panels for pathologic differential diagnosis.

MATERIALS AND METHODS

RIHC based on ultrasonic thermal steam heating was tested for intraoperative frozen diagnosis with difficulty in diagnosis, and all slides were reviewed and compared with the final diagnosis. Ninety-three cases of surgical specimens involving RIHC examination were studied. Discordance rates with paraffin immunohistochemistry were calculated.

RESULTS

In 93 cases where RIHC was performed, 85 cases (91%) were proven to be helpful for the diagnosis. A total of 58 antibodies were used for RIHC 276 times, of which 19 antibodies were not effective 25 times. Fifteen RIHC antibody panels are recommended based on staining stability and utilization frequency.

CONCLUSION

After improving the staining method, ultrasonic thermal steam heating RIHC is practical, convenient, and cost-effective, making it suitable for use in any pathology department with routine immunohistochemistry reagents. It plays an important auxiliary role in improving the accuracy of intraoperative rapid pathologic diagnosis.

Validity of surgical decision based on intraoperative frozen section diagnosis for unconfirmed pulmonary nodules with previous malignancy

OBJECTIVES

The lung is a major target organ of metastasis in several cancers. To distinguish primary lung cancer from pulmonary metastases is a clinical challenge. Small pulmonary nodules (PNs) are frequently diagnosed by frozen section diagnosis (FSD) intraoperatively after resection. Intraoperative FSD is very important to determine the extent of subsequent surgical procedures. This study aimed to know the validity of surgical decision based on FSD for preoperatively unconfirmed PN with previous malignancy.

METHODS

We retrospectively evaluated 96 patients with suspected malignant PN who underwent intraoperative FSD between 2018 and 2020. Intraoperative FSD, final diagnosis, and surgical procedure data were examined.

RESULTS

Surgical procedure adequacy, based on FSD for preoperatively unconfirmed PN with previous malignancy, was 91% (88/96). The overall diagnostic accuracy of FSD was 83.3% (80/96). Discrepancy was noted in two cases (2.1%), and conclusive diagnosis could not be reached intraoperatively in 14 cases (14.6%). A second surgery was required in three patients and no additional excision for primary lung cancer was performed in three patients. Conversely, there were three cases of over-surgery, namely, lobectomy for pulmonary metastasis.

CONCLUSIONS

Surgical decision-making based on FSD for preoperatively unconfirmed PN in patients with previous malignancy was generally adequate. However, there were inadequate or excessive surgical procedures due to limitations in the accuracy of intraoperative FSD. Improving the accuracy of intraoperative FSD is a necessary step for obtaining adequate surgical decision-making and precision medicine.

Utility of mass spectrometry and artificial intelligence for differentiating primary lung adenocarcinoma and colorectal metastatic pulmonary tumor

Background

Rapid intraoperative diagnosis for unconfirmed pulmonary tumor is extremely important for determining the optimal surgical procedure (lobectomy or sublobar resection). Attempts to diagnose malignant tumors using mass spectrometry (MS) have recently been described. This study evaluated the usefulness of MS and artificial intelligence (AI) for differentiating primary lung adenocarcinoma (PLAC) and colorectal metastatic pulmonary tumor.

Methods

Pulmonary samples from 40 patients who underwent pulmonary resection for PLAC (20 tumors, 20 normal lungs) or pulmonary metastases originating from colorectal metastatic pulmonary tumor (CRMPT) (20 tumors, 20 normal lungs) were collected and analyzed retrospectively by probe electrospray ionization‐MS. AI using random forest (RF) algorithms was employed to evaluate the accuracy of each combination.

Results

The accuracy of the machine learning algorithm applied using RF to distinguish malignant tumor (PLAC or CRMPT) from normal lung was 100%. The algorithms offered 97.2% accuracy in differentiating PLAC and CRMPT.

Conclusions

MS combined with an AI system demonstrated high accuracy not only for differentiating cancer from normal tissue, but also for differentiating between PLAC and CRMPT with a short working time. This method shows potential for application as a support tool facilitating rapid intraoperative diagnosis to determine the surgical procedure for pulmonary resection.

Prognostic Impact of Frozen Section Investigation and Extent of Proximal Safety Margin in Gastric Cancer Resection

BACKGROUND AND AIMS

Guidelines propose different extents of macroscopic proximal margin for gastric cancer and frozen margin investigation in selected cases, but data is lacking. This study was to evaluate the necessary extent of macroscopic proximal margin, accuracy of frozen margin investigation, and prognostic impact of tumor-free proximal margin length in pT2-pT4 gastric cancer.

STUDY DESIGN

Proximal and distal frozen margins were routinely investigated intraoperatively in all pT2-pT4 gastric cancers resected between 2011 and 2017. Macroscopic and microscopic proximal margin lengths were correlated. For R0-resections, survival analysis was performed for distal gastrectomy (DG) with microscopic proximal margin length ≤3 cm versus >3 cm.

RESULTS

Overall, 1484 patients were included. Microscopic proximal margin lengths were macroscopically more often misestimated in diffuse histology (P = 0.0004), but extent of underestimation in centimeter was similar to intestinal and mixed/undetermined type (P = 0.134). Fifteen cases (1.0%) resulted in R1-resection, 10 at distal, and 5 at proximal margin but none with macroscopic proximal margin ≥3 cm and negative frozen section. Overall agreement of frozen margin and final pathology was 2951/2968 (99.4%). Proximal margin length in DG did not correlate with survival or recurrence in R0-resected patients.

DISCUSSION

Diffuse histology is at higher risk for underestimation of proximal margin length, but extent of underestimation is similar in other Laurén subtypes. If ≥3 cm macroscopic proximal margin length is applied with intraoperative frozen margin confirmation, R1-resection can be avoided.

CONCLUSION

In pT2-T4a gastric cancer, proximal margin of ≥3 cm plus frozen margin confirmation provides high oncological safety. In DG patients with R0-resection, proximal margin length does not correlate with survival or recurrence.