Israel Medical Association Journal

Background: Frozen section (FS) is often performed when histopathological evaluations are urgently required for implementation of therapeutic measures. In dermatology, this method is most commonly used to evaluate excision margins of tumors. FS are also routinely employed to differentiate toxic epidermal necrolysis from staphylococcal scalded skin syndrome. However, little is currently known about the performance of FS in the diagnosis of inflammatory dermatoses.

Objectives: To compare histopathological diagnoses in a series of patients with a clinical diagnosis of an inflammatory dermatosis for which FS and paraffin-section (PS) specimens were obtained on the same day.

Methods: We conducted a single-center retrospective analysis of 43 cases. All histological slides were reviewed by a single dermato-pathologist. Concordance was calculated between FS and PS.

Results: Patients were divided into three groups according to diagnosis: papulosquamous diseases (group I), drug eruptions (group II), and a heterogeneous group (group III) that included cases of bullous vasculitis and Sweet syndrome. Among the three groups, the results of FS and of PS were discordant only in five cases (5/43, 11.6%). Compared to PS, FS had a sensitivity of 92.9% [95% confidence interval (95%CI) 64.17–99.63%] and a specificity of 100% in group I, sensitivity of 90.9% (95%CI 57.12–99.52%) and specificity of 100% in group II, and sensitivity of 83.33% (95%CI 60.78–94.16%) and specificity of 100% in group III. The degree of agreement between the results of the FS and of the PS was almost perfect (kappa = 0.95, 0.93 and 0.85 respectively).

Conclusions: This study suggests that FS is a valid approach for the rapid diagnosis of inflammatory dermatoses. This method is as specific as PS, although it is less sensitive.

Background: Direct aspiration from suspected pathological tissue and rapid parathyroid hormone analysis may offer a reliable, cost effective alternative to currently used “gold standard” tests.

Objectives: To validate the accuracy of intraoperative measurements of parathyroid hormone levels in parathyroid adenomas.

Methods: A prospective study included 22 patients diagnosed with primary hyperparathyroidism who underwent parathyroidectomy due to an adenoma or hyperplasia. Aspirations of tissues extracted from three adjacent areas (the pathological parathyroid, thyroid, and muscle tissues) were sent for rapid parathyroid hormone analysis. The assay values of these tissue aspirates were compared to the results of the pathology report based on frozen section analysis and the final pathology report.

Results: All assay results were significantly higher for parathyroid tissue 16,800 to 1,097,986 pmol/L (median 26,600), than for either thyroid 1.7 to 415 pmol/L (median 6.5), P < 0.001, or muscle tissue 1.1 to 1230 pmol/L, (median 11.3), P < 0.001. All tissues showing high parathyroid assay values were also verified by pathology examinations: 7 had adenomas and 15 had a differential diagnosis of adenoma or hyperplasia. The frozen section identified all but one (false negative). Rapid intraoperative parathyroid levels > 1500 predicted parathyroid tissue with a 99% level of confidence, while levels between 1000 and 1500 predicted it with 95% confidence. The intraoperative parathyroid hormone assay showed > 70% decrease in 15/21 cases.

Conclusions: Rapid intraoperative parathyroid hormone analysis is a reliable and precise technique, equally accurate for frozen section analysis in predicting with high certainty intraoperative parathyroid tissue.

Background: Fine needle aspiration is the main diagnostic tool used to assess thyroid nodules.

Objectives: To correlate FNA[1] cytology results with surgical pathological findings in two teaching medical centers across the Atlantic.

Methods: We retrospectively identified 484 patients at Hadassah University Hospital, Jerusalem and Mount Sinai Hospital, New York, by means of both preoperative FNA cytology and a final histopathological report. Results compared FNA diagnosis, histological findings and frozen section results (Mt. Sinai only).

Results: The sensitivity value of FNA at Hadassah was 83.0% compared with 79.1% at Mt. Sinai (NS). Specificity values were 86.6 vs. 98.5% (P < 0.05), negative predictive value 78.7 vs. 77.6% (NS) and positive predictive value 89.7 vs. 98.6% (P < 0.05), respectively. "Follicular lesion" was diagnosed on FNA in 33.1% of the patients at Hadassah and in 21.5% at Mt Sinai (P < 0.005) with a malignancy rate of 42.5 vs. 23.1% (P < 0.05), respectively. Frozen section was used in 190 patients at Mt. Sinai (78.5%) with sensitivity and specificity values of 72.3% and 100%. Frozen section results altered the planned operative course in only 6 patients (2.5%). Follicular carcinoma was diagnosed in 12 patients at Hadassah vs. 2 patients at Mt. Sinai (P p <0.05).

Conclusion: The sensitivity of FNA at the two institutions was comparable. While malignancy on frozen section is highly specific, it should be used selectively for suspicious FNA results. Follicular lesions and the rate of malignancy in such lesions were more common at Hadassah, favoring a more aggressive surgical approach.

Background: Skin basal and squamous cell carcinomas together account for over half of all newly diagnosed cancer cases. Frozen  section control of surgical margins is often required in the head and neck region. A paraffin permanent section does not always confirm the results of a frozen section.

Objectives: To test the diagnostic accuracy of frozen section histopathological analysis in determining the free margins of excised tumors.

Methods: This was a retrospective study of 169 cutaneous basal and squamous cell carcinomas excised with surgical margins diagnosed by frozen section and confirmed by permanent paraffin sections. The data included patients' age, gender, clinical and histopathological diagnosis, as well as characteristics of the lesions.

Results: There were 149 (88%) basal cell carcinomas and 20 (12%) squamous cell carcinomas. False negative margins were found in 19 cases (11.2%) and false positive margins in 11 cases (6.6%). We did not find any correlation between false positive or false negative margins and patients' age, gender, tumor size, tumor location, or the presence of sun-damaged skin. A significantly lower rate of false negative results was found in the residual tumor group.

Conclusions: Our findings show support the use of frozen section margin control in selected patients suffering from non-melanoma skin cancer of the head and neck.