Female, 8 years. Papule, skin of backShow diagnosis & comments
Spitz tumour of uncertain malignant potential (STUMP), regarded by some as spitzoid melanoma.
Some Spitzoid melanocytic proliferations of prepubertal children present with deep, miotitcally active nodules bulging into the deep dermis or even subcutis. Spread to regional lymph nodes is seen repeatedly and to those who regard spread to a regional node as formal proof of malignancy, this means that these lesions are (spitzoid) melanomas. Ohers have pointed out that children with such tumors and nodal deposits do remarkably well, and that distant metastasis appears to be very rare, much rare than one would expect in case of thick melanoma NOS with a positive regional lymh node. For te time being, I therefore regard these lesions as STUMP (Spitz tumor of uncertain malignant potential). Hopefully, future work and clinical experience will shed more light on this issue.
The S-100 immunostain shows the regular architecture of the superficial portion of the lesion, and the downward bulging compact basal component.
- Mones JM, Ackerman AB. "Atypical" Spitz's nevus, "malignant" Spitz's nevus, and "metastasizing" Spitz's nevus: a critique in historical perspective of three concepts flawed fatally. Am J Dermatopathol. 2004 Aug;26(4):310-33.
- Mones JM, Ackerman AB. Melanomas in prepubescent children: review comprehensively, critique historically, criteria diagnostically, and course biologically. Am J Dermatopathol. 2003 Jun;25(3):223-38.
- Mooi WJ, Krausz T. Spitz nevus versus spitzoid melanoma: diagnostic difficulties, conceptual controversies. Adv Anat Pathol. 2006 Jul;13(4):147-56.
- Ackerman AB, Mones JM. Rudimentary/elementary. Adv Anat Pathol. 2007 Mar;14(2):143-4; author reply 144-5.