Tuesday, January 07, 2014

Atypical Spitz Nevus

Presented by: Hamish Dunwoodie, M.D.
Northern Dermatology Associates
Flin Flon, Manitoba, Canada

Abstract: 8 yo boy with few months history of erythematous papule right calf

HPI: This 8 yo boy was originally seen in August 2013 for a lesion on the right calf whih had been present for 2 months.  Clinically, it looked like a pyogenic granuloma.  It was shave excised and the base cauterized.  A specimen was sent for pathology, but the report was not seen.  Three months later his parents called to say the lesion had recurred.  The biopsy report was checked and it was learned that this was an atypical Spitz nevus.  The patient was seen in follow-up for a reexcision.

O/E: On both occasions, the lesion was an erythematous papule measuring 8 mm in diameter.  It looked vascular.

Clinical Photos:


There is a proliferation of epitheloid melanocytes arranged in large nests superficially and slender fascicles deeper n the lesion.  The lesion is completelhy excised but focally close to a lateral margin..

Diagnosis: Atypical compound spindle and epithelioid cell (Spitz) nevus 

Discussion: These are difficult lesions histologically.  In untrained eyes, they can be mistaken for melanoma or STUMP (Spitzoid tumors of uncertain malignant potential) lesions.  Pathologically, this lesion was felt to be benign and the patient will be followed.

References: These references will be helpful in managing this and similar patients.
1.  Long-term outcome of Spitz-type melanocytic tumors.
Sepehr A, Chao E, Trefrey B, Blackford A, Duncan LM, Flotte TJ, Sober A, Mihm MC Jr, Tsao H.
Arch Dermatol. 2011 Oct;147(10):1173-9. Full Text.

2.  Differences in treatment of spitz nevi and atypical spitz tumors in pediatric patients among dermatologists and plastic surgeons. Metzger AT, Kane AA, Bayliss SJ.  Full Text.
Corresponding Author: AT Metzgar: ametzgarATtulane.edu 
JAMA Dermatol. 2013 Nov 1;149(11):1348-50.

Because of the lack of large studies of Spitz nevi and atypical spitz tumors, no evidence-based treatment recommendations can be made. Most current sources recommend complete excision to facilitate complete histologic evaluation and reduce risk of recurrence.   In actual clinical practice, though, dermatologists seem to consider age in their choice of management, as evidenced by the larger proportion who would observe an SN in a 7-year-old compared with an 18-year-old

Pediatric "STUMP" lesions: evaluation and management of difficult atypical Spitzoid lesions in children.
Tom WL, Hsu JW, Eichenfield LF, Friedlander SF.
J Am Acad Dermatol. 2011 Mar;64(3):559-72 (Not available OA)
Spitz nevi represent a distinct type of melanocytic nevi more commonly seen in childhood. Although typically benign, a subset of Spitz lesions raise concern and create a diagnostic dilemma as a result of confusing histology that involves characteristics of classic Spitz nevi intermixed with features of cutaneous melanoma. Such atypical Spitz lesions, or Spitzoid tumors of uncertain malignant potential, are difficult to classify and their biologic potential is uncertain. Nonetheless, these are critical tasks for both prognosis and clinical management. New tools, such as immunohistochemical stains, comparative genomic hybridization, and fluorescence in situ hybridization, have been used to provide further insight into these controversial lesions and to aid in their evaluation. In this review, we present our experience managing 6 cases of Spitzoid tumor of uncertain malignant potential and discuss the potential use of various diagnostic modalities, including sentinel lymph node biopsy, immunostaining, and molecular analysis.


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