Sentinel node procedure in vulvar squamous cell carcinoma: a histomorphologic review of 32 cases. The significance of anucleate structures on immunohistochemistry.

The sentinel lymph node (SLN) procedure is used in our institute in the setting of an observational multicenter study investigating the reliability of the sentinel node procedure in vulvar carcinoma (GROINSS-V: The Groningen International Study on Sentinel Nodes in Vulvar Cancer). One of our patients had a groin recurrence where the SLN had been reported as negative. After reviewing this SLN, it contained several anucleate, keratin-positive structures on immunohistochemistry, and in the same area on hematoxylin and eosin coloring, one single cell with a nucleus interpreted as a tumor cell. Our objective was to assess how frequently these anucleate structures occur and whether such nodes should be regarded as positive. The sentinel nodes from 32 patients with early-stage vulvar squamous cell carcinoma were reviewed. Seventy-seven SLN's were identified. In ten patients, the SLN was positive and a bilateral inguinofemoral lymph node dissection was subsequently performed. In two of these ten patients, both with a macrometastasis on SLN, further metastatic disease was present in the dissection specimen. Anucleate keratin-positive structures were seen on immunohistochemistry in 14 SLN's (18%), usually along with metastasis or single tumor cells, but in five nodes this was the only abnormality (mean follow-up period of 26.28 months). Anucleate keratin-positive structures are a common finding in immunohistochemical examination of SLN's. Our findings suggest that they are of no clinical significance and the SLN should be regarded as negative. When an atypical cell with a nucleus is present, the SLN should be classified as positive and further management should be accordingly.

Collagen content and distribution in the normal and transplanted human heart: A postmortem quantitative light microscopic analysis.

Endomyocardial biopsies in heart transplant patients offer the opportunity to study the myocardial interstitium in the context of myocardial function. For that purpose endomyocardial biopsies should reliably reflect the composition of the entire myocardium. We determined whether the collagen content in the subendocardial region of the right side of the interventricular septum (site of right ventricular endomyocardial biopsy), in 16 normal and 30 transplanted human hearts, is representative for the entire myocardium. Moreover we determined whether or not the mean collagen content of the myocardium is altered along with the posttransplantation survival time and which factors might contribute to the development of interstitial myocardial fibrosis. Transmural sections of the right and left ventricular free wall and interventricular septum were stained with Sirius red, which specifically stains collagen fibers. Collagen in the subendocardial region and central parts of the myocardium was quantified using a digital image analyzer. In normal hearts the mean collagen content of the subendocardial region of the right side of the interventricular septum (site of right ventricular endomyocardial biopsy) correlates well with the mean collagen content of the right ventricular wall and the center of the interventricular septum, but it does not reliably reflect the mean collagen content of the left ventricular free wall. In transplanted hearts the collagen content at the site of right ventricular endomyocardial biopsy correlates highly with the mean collagen content of the entire myocardium. In transplanted hearts the increase in collagen content is a result mainly of an increase in collagen of the left ventricular free wall. We conclude that in heart transplant patients, right ventricular endomyocardial biopsies have potential value in the analysis of the causes of left ventricular dysfunction. In transplanted human hearts, the posttransplantation survival time correlates positively with the collagen content, and this is attributable mainly to an increase in the collagen of the left ventricular free wall.