Metastatic Melanoma in Sentinel Node-Negative Patients: The Ottawa Experience.

BACKGROUND: Lymph node involvement is a major independent prognostic factor for survival in patients with malignant melanoma. Sentinel lymph node biopsy (SLNB) detection of microscopic nodal melanoma has been shown to improve both 5-year survival and 5-year disease-free survival. OBJECTIVE: To determine the rate of metastatic melanoma in SLNB-negative patients at long-term follow-up. METHODS: Study subjects include all 152 patients who had a negative SLNB and were followed at the Ottawa Regional Cancer Centre (ORCC) between 1999 and 2004. Patients with a follow-up period less than 6 months, more than 1 primary melanoma, and metastatic melanoma at diagnosis were excluded. Age at diagnosis, sex, Breslow thickness, ulceration, mitoses, regression, Clark level, anatomical location, development of metastatic melanoma, time to detection of metastatic disease, and time to death from melanoma were studied. RESULTS: In this retrospective study at the ORCC, 40 of 140 (28.6%) patients with a single primary melanoma developed metastatic melanoma following negative SLNB at a mean follow-up of 63 months. CONCLUSION: The rate of metastatic melanoma following negative SLNB at long-term follow-up at the ORCC is higher than the upper limit of rates reported in the literature (6%-24%). The reason for this is multifactorial, and the long follow-up period of 5 years allowed for detection of metastatic disease at a mean of 3.9 years. Long-term prognosis may be guarded in node-negative patients with a primary cutaneous melanoma, and surveillance by a multidisciplinary team is crucial.

Cutaneous T-cell lymphoma-like drug eruption in an HIV-positive patient taking vancomycin and rifampin.

BACKGROUND: Cutaneous T-cell pseudolymphoma (CTPL) is a benign reactive T-cell lymphoproliferative subtype of pseudolymphoma. Some variants of CTPL can resemble the plaques of mycosis fungoides (MF). The vast majority of drug-induced cases have been associated with anticonvulsants. There is only one report in the literature documenting a case of vancomycin-induced CTPL. METHODS: We report a cutaneous T-cell lymphoma-like eruption in a human immunodeficiency virus (HIV)-positive patient recently started on vancomycin and rifampin. RESULTS: A skin biopsy showed several histologic features of MF with immunohistochemical and T-cell receptor gene rearrangement studies suggestive of CTPL. This atypical T-cell reaction mimicking MF completely resolved on cessation of rifampin followed by vancomycin. CONCLUSION: Considering drug-induced causes of MF-like histologic changes is crucial to prevent unnecessary treatment for MF.