Small and Isolated Immunohistochemistry-positive Cells in Melanoma Sentinel Lymph Nodes Are Associated With Disease-specific and Recurrence-free Survival Comparable to that of Sentinel Lymph Nodes Negative for Melanoma

Prognostic Significance of Size, Location, and Number of Lymph Node Metastases in Endometrial Carcinoma

Regional lymph node metastasis is a well-established negative predictive prognostic factor in endometrial carcinomas. Recently, our approach to the pathologic evaluation of lymph nodes in endometrial carcinomas has changed, mainly due to the utilization of immunohistochemical stains in the assessment of sentinel lymph nodes, which may result in the identification of previously unrecognized disease [particularly isolated tumor cells (ITCs)] on hematoxylin and eosin stained slides. However, the clinical significance of this finding is not entirely clear. Following the experience in other organs systems such as breast, the Eight Edition of the American Joint Committee on Cancer's Cancer Staging Manual has recommended utilizing the N0(i+) terminology for this finding, without impact in the final tumor stage. We performed a comparative retrospective multi-institutional survival analysis of 247 patients with endometrial carcinoma with regional lymph node metastasis of various sizes identified in nonsentinel lymphadenectomy, demonstrating that the cumulative survival of patients with isolated tumor cells in regional lymph nodes is not statistically different from patient with negative lymph nodes, and is statistically different from those with lymph nodes showing micrometastasis or larger metastatic deposits. In addition, we evaluated the prognostic implications of the number of involved regional lymph nodes, demonstrating a worsening prognosis as the number of involved lymph nodes increases from none to one, and from one to more than one. Our data suggests that regional lymph nodes with isolated tumor cells in patients with endometrial carcinoma should likely be considered, for staging purposes, as negative lymph nodes, simply indicating their presence with the (i+) terminology.

Reporting of melanoma cell densities in the sentinel node refines outcome prediction

INTRODUCTION

Sentinel node biopsy is a key procedure to predict prognosis in melanoma. In a prospective study we compare reporting on melanoma cell densities in cytospin preparations with semiquantitative histopathology for predicting outcome.

PATIENTS AND METHODS

Sentinel nodes from 900 melanoma patients were bisected. One half of each node was disaggregated mechanically. The melanoma cell density (number of HMB45 positive cells per million lymphocytes with at least one cell showing morphological features of a melanoma cell) was recorded after examining two cytospins. For the second half the maximum diameter of metastasis was determined after haematoxylin and eosin (H&E) and immunohistological staining of three slides.

RESULTS

Cytospins were positive for melanoma in 218 of 900 patients (24%). Routine pathology was positive in 111 of 900 (12%) patients. A more extensive pathological workup in cytospin-only positive patients led to a revised diagnosis (from negative to positive) in 23 of 101 patients (22.7%). We found a moderate but significant correlation between melanoma cell densities (determined in cytospins) and the maximum diameter of metastasis (determined by pathology) (rho = 0.6284, p < 0.001). At a median follow-up of 37 months (IQR 25-53 months) melanoma cell density (cytospins) (p < 0.001), thickness of melanoma (p = 0.008) and ulceration status (p = 0.026) were significant predictors for melanoma specific survival by multivariable testing and were all confirmed as key predictive factors by the random forest model. Maximum diameter of metastases, age and sex were not significant by multivariable testing (all p > 0.05).

CONCLUSION

Recording melanoma cell densities by examining two cytospins accurately predicts melanoma outcome and outperforms semiquantitative histopathology.

Picomets: Assessing single and few cell metastases in melanoma sentinel lymph node biopsies

BACKGROUND

Lymph node involvement is a significant prognostic factor for melanoma. Both number of positive nodes and disease burden within a lymph node affects survival. However, the significance of few tumor cells within a single node and subsequent optimal management remains without consensus. We investigated the implications of minimal nodal disease on clinical outcomes.

METHODS

We reviewed 752 patients who underwent lymph node sampling at time of primary melanoma resection at our institution over 15 years. We deemed patients who had 1 node with 1 to 4 atypical cells staining positive for either Melan-A or Sox-10 as having "picomets." We examined the initial clinicopathological features, subsequent management, and outcomes.

RESULTS

Thirty-three patients (4%) met criteria for having picomets. The most common number of positively staining atypical cells was 1 (n = 13). Nodal staging at initial pathology review varied, and overall stage ranged from IA to IIIC. Four patients underwent further therapy, none of whom had recurrent disease. Of the 29 patients undergoing observation/surveillance only, 5 had disease recurrence (17%).

CONCLUSION

Although patients with picomets had better outcomes than historical stage matched cohorts, a small subset had recurrent disease. Staging patients with picomets as "N0" may not reflect the true negative prognostic significance of picomets. A larger population of patients meeting picomets criteria is needed to draw further conclusions.

Pathology of sentinel lymph nodes: historical perspective and current applications in gynecologic cancer

Efforts to reduce surgical morbidity related to en bloc lymph node removal associated with cancer surgery led to the development of targeted lymph node sampling to identify the lymph node(s) most likely to harbor a metastasis. Through identification of one or only a few lymph nodes at highest risk, the overall number of lymph nodes removed could be markedly reduced. Submission of fewer lymph nodes affords more detailed pathologic examination than would otherwise be practical with a standard lymph node dissection. Such enhanced pathologic examination techniques (ie, ultra-staging) have contributed to increased detection of lymph node metastases, primarily by detection of low volume metastatic disease. Based on the success of sentinel lymph node mapping and ultra-staging in breast cancer and melanoma, such techniques are increasingly used for other organ systems including the gynecologic tract. This review addresses the historical aspects of sentinel lymph node evaluation and reviews current ultra-staging protocols as well as the implications associated with increased detection of low volume metastases.