Case 20 Male, 35 years. Verrucous lesion of skin, back.Show diagnosis & comments
Spitzoid superficial spreading melanoma
Since Spitz naevus resembles melanoma more closely than other naevus types (Sophie Spitz originally considered them to be melanomas that, for some reason, did not manifest their malignant potential in children), it follows that melanomas not uncommonly resemble Spitz naevus.
If the resemblance is striking, such melanomas are sometimes referred to as 'spitzoid melanomas'. Since this resemblance is independent of other parameters that allow subtyping of melanoma, there are spitzoid superficial spreading melanomas, spitzoid nodular melanomas, etc.
The spitzoid appearance does not have a bearing on the melanoma in terms of biological behaviour (as is the case here), with one important exception: in young (prepubertal) children: spitzoid tumours with deep bulky nodular and mitotically active outgrowth spread to regional nodes but rarely metastasize to distant sites. Such tumours, which have a substantially better prognosis that usual melanoma subtypes of similar thickness, are subject of controversy regarding appropriate terminology. See for instance Case 14 of this slide set.
- 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.