Israel Medical Association Journal

Background: In colon cancer, data regarding proximal and distal metastasis to lymph nodes remains scarce.

Objectives: To evaluate lymph node distribution along the longitudinal axis of the colon as related to a tumor to re-examine the common practice of 5 cm proximal and 2 cm distal resection margins.

Methods: We studied 106 patients (53 males and 53 females, mean age 67.9 ± 10 years) who had undergone left hemicolectomy or sigmoidectomy. Colonic cancer specimens were divided into five zones proximally and distally to the tumor. For each zone, overall lymph node evaluation and ratio was performed.

Results: The mean number of retrieved lymph nodes per patient was 24.3 ± 12, with 54.9% of the nodes concentrated in zone I, 22.1% in zone II, 9.5% in zone III, 10.3% in zone IV, and 3% in zone V. While most positive nodes were found in zone I, significant numbers were also detected in both directions proximally and distally to the tumor.

Conclusions: It seems that longer colonic segments proximally, and especially distally, should be considered for resection to significantly reduce the chances of finding involved lymph node.

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.