Abstract
BACKGROUND
Spindle and/or epithelioid melanocytic proliferations that display overlapping histopathologic features of Spitz nevus and Spitzβlike melanoma are diagnostically difficult and controversial melanocytic tumors. There are reports of such lesions metastasizing to regional lymph nodes, with a few widely disseminating, resulting in death.
METHODS
The authors reviewed clinical and histopathologic data on all patients with atypical or borderline spitzoid melanocytic proliferations who underwent sentinel lymph node biopsy (SLNB). They examined how frequently histologically problematic or borderline spitzoid melanocytic lesions metastasized to sentinel lymph nodes (SLNs) and which clinical or histologic features, if any, predisposed patients to a higher risk lesion.
RESULTS
Six male patients and 12 female patients, ages 5β32 years (mean, 16 years), had tumors ranging in size from 1.2 mm to 7.9 mm (mean, 3.5 mm) in thickness. Atypical histologic features that were present most frequently included incomplete maturation (18 of 18 patients), deep dermal mitoses (16 of 18 patients), nuclear pleomorphism (10 of 18 patients), and focal sheetβlike growth (10 of 18 patients). Eight of 18 patients (44%) had SLN metastasis and were offered adjuvant treatment. One of eight patients with SLN positive results who underwent regional lymphadenectomy had one additional involved lymph node. All 18 patients were alive and well with no evidence of recurrent or metastatic disease after a followβup of 3β42 months (mean, 12 months).
CONCLUSIONS
Histologically atypical or borderline spitzoid, melanocytic tumors are diagnostically challenging and controversial melanocytic lesions, some of which represent unrecognized melanomas. SLNB aids in confirming a diagnosis of melanoma and identifies patients who may benefit from early therapeutic lymph node dissection and/or adjuvant therapy. Cancer 2003;97:499β507. Β© 2003 American Cancer Society.
DOI 10.1002/cncr.11074