ABSTRACT
BACKGROUND: Sentinel lymph node biopsy (SLNB) is the standard at many institutions caring for melanoma patients. Patients with positive SLNB results are currently offered completion lymph node dissection (CLND) of the affected lymph node basin. This procedure entails considerable morbidity and is often applied to patients with shortened life expectancies. Because 80% of CLNDs yield no additional positive nodes and there is no proof that CLND leads to survival improvement, criteria are needed to limit this procedure to those most likely to harbor nonsentinel lymph node (SLN) metastases. METHODS: A retrospective review of 349 cases of melanoma from January 1999 to April 2007 that underwent sentinel lymph node biopsy at a single institution was done. Statistical analysis was used to compare two subgroups of patients: a positive CLND group and a negative CLND group. These two groups were compared with regards to multiple variables related to patient demographics, primary tumor characteristics, and SLN tumor burden. RESULTS: Age and total size of SLN tumor deposit were the factors with the strongest correlation with CLND positivity. By applying a risk score model that uses the cutoff values of age 55 y and SLN tumor deposit of 5 mm, it is possible to predict CLND positivity in SLN-positive melanoma patients. CONCLUSION: The likelihood of CLND positivity in SLN-positive melanoma patients can be predicted from two criteria readily available: size of SLN tumor deposit and patient age.
Subject(s)
Biopsy , Lymph Nodes/pathology , Melanoma/secondary , Skin Neoplasms/secondary , Aged , Female , Humans , Lymph Node Excision , Lymph Nodes/surgery , Lymphatic Metastasis , Male , Middle Aged , Predictive Value of Tests , Prognosis , Retrospective Studies , Sentinel Lymph Node BiopsyABSTRACT
Merkel cell carcinoma is an aggressive neuroendocrine tumor historically thought to arise from neural crest-derived cutaneous neuroendocrine cells. Recent evidence supports an epidermal origin. We present a case of Merkel cell carcinoma arising on the upper arm of a 94-year-old woman that had multiple morphologic patterns: small cells typical of Merkel cell carcinoma, malignant cells with squamous differentiation and malignant poorly differentiated spindle cells. Subsequent metastatic disease in regional lymph nodes showed only the small cells and the malignant spindle cells. To our knowledge, this is the first case of Merkel cell carcinoma showing these three patterns of differentiation at first presentation. This morphology raises the possibility that Merkel cell carcinomas may arise from epidermal stem cells that can differentiate along different lines.
