Background
Physicians have known for almost a century that some childhood lesions histologically diagnosed as melanomas did not show malignant behavior. The terms juvenile melanoma and prepubertal melanoma were used to describe such lesions.
After Spitz's original report of a series of patients, several attempts were made to establish objective criteria that would clearly delineate Spitz nevi and melanomas. The controversial classification of some cases as metastasizing Spitz nevi further confounded the issue; however, such cases illustrate the difficulty of accurately distinguishing some Spitz nevi from melanoma based on histological criteria alone. Even today, no set of criteria can be used to predict the clinical outcome of atypical Spitz tumors with absolute assurance.
Pathophysiology
A Spitz nevus can arise de novo or in association with an existing melanocytic nevus.
Epidemiology
Frequency
International
Exact data on incidence or prevalence are not available. Spitz nevi are estimated to represent less than 1% of all childhood melanocytic nevi.
Mortality/Morbidity
These lesions are clinically benign. A 2011 study reporting on 157 patients with Spitz-type melanotic lesions suggests that atypical Spitz tumors pose a minimal threat of mortality but have an increased risk of melanoma and a moderate risk of metastasis to regional nodes. Aggressive treatment is usually not needed, but monitoring for signs of relapse, as well as subsequent melanomas, is recommended.[1]
Race
Spitz nevi have been described most frequently in fair-skinned individuals. One study reviewed 130 cases in a Hispanic population, demonstrating that Spitz nevi are not restricted to white patients.[2]
Sex
Both sexes are equally affected. Some authors describe a slight female predominance.
Age
About 50% of cases occur in children younger than 10 years; 70% of all cases are diagnosed during the first 2 decades of life.
Sepehr A, Chao E, Trefrey B, et al. Long-term Outcome of Spitz-Type Melanocytic Tumors. Arch Dermatol. Oct 2011;147(10):1173-9. [Medline].
Berlingeri-Ramos AC, Morales-Burgos A, Sánchez JL, Nogales EM. Spitz Nevus in a Hispanic Population: A Clinicopathological Study of 130 Cases. Am J Dermatopathol. Jan 22 2010;[Medline].
Rossiello L, Zalaudek I, Ferrara G, Docimo G, Giorgio CM, Argenziano G. Melanoacanthoma simulating pigmented spitz nevus: an unusual dermoscopy pitfall. Dermatol Surg. May 2006;32(5):735-7. [Medline].
Fullen DR, Poynter JN, Lowe L, et al. BRAF and NRAS mutations in spitzoid melanocytic lesions. Mod Pathol. Oct 2006;19(10):1324-32. [Medline].
Gill M, Cohen J, Renwick N, Mones JM, Silvers DN, Celebi JT. Genetic similarities between Spitz nevus and Spitzoid melanoma in children. Cancer. Dec 1 2004;101(11):2636-40. [Medline].
van Dijk MC, Bernsen MR, Ruiter DJ. Analysis of mutations in B-RAF, N-RAS, and H-RAS genes in the differential diagnosis of Spitz nevus and spitzoid melanoma. Am J Surg Pathol. Sep 2005;29(9):1145-51. [Medline].
Da Forno PD, Fletcher A, Pringle JH, Saldanha GS. Understanding spitzoid tumours: new insights from molecular pathology. Br J Dermatol. Jan 2008;158(1):4-14. [Medline].
Egberts F, Kaehler KC, Brasch J, Schwarz T, Cerroni L, Hauschild A. Multiple skin metastases of malignant melanoma with unusual clinical and histopathologic features in an immunosuppressed patient. J Am Acad Dermatol. May 2008;58(5):880-4. [Medline].
Nojavan H, Cribier B, Mehregan DR. [Desmoplastic Spitz nevus: a histopathological review and comparison with desmoplastic melanoma]. Ann Dermatol Venereol. Oct 2009;136(10):689-95. [Medline].
Ko CJ, McNiff JM, Glusac EJ. Melanocytic nevi with features of Spitz nevi and Clark's/dysplastic nevi ("Spark's" nevi). J Cutan Pathol. Oct 2009;36(10):1063-8. [Medline].
Gelbard SN, Tripp JM, Marghoob AA, et al. Management of Spitz nevi: a survey of dermatologists in the United States. J Am Acad Dermatol. Aug 2002;47(2):224-30. [Medline].
Murphy ME, Boyer JD, Stashower ME, Zitelli JA. The surgical management of Spitz nevi. Dermatol Surg. Nov 2002;28(11):1065-9; discussion 1069. [Medline].
Luo S, Sepehr A, Tsao H. Spitz nevi and other Spitzoid lesions part I. Background and diagnoses. J Am Acad Dermatol. Dec 2011;65(6):1073-84. [Medline]. [Full Text].
Boer A, Wolter M, Kneisel L, Kaufmann R. Multiple agminated Spitz nevi arising on a cafe au lait macule: review of the literature with contribution of another case. Pediatr Dermatol. Nov-Dec 2001;18(6):494-7. [Medline].
Dal Pozzo V, Benelli C, Restano L, Gianotti R, Cesana BM. Clinical review of 247 case records of Spitz nevus (epithelioid cell and/or spindle cell nevus). Dermatology. 1997;194(1):20-5. [Medline].
Ferrara G, Argenziano G, Soyer HP, et al. The spectrum of Spitz nevi: a clinicopathologic study of 83 cases. Arch Dermatol. Nov 2005;141(11):1381-7. [Medline].
Harvell JD, Bastian BC, LeBoit PE. Persistent (recurrent) Spitz nevi: a histopathologic, immunohistochemical, and molecular pathologic study of 22 cases. Am J Surg Pathol. May 2002;26(5):654-61. [Medline].
Kapur P, Selim MA, Roy LC, Yegappan M, Weinberg AG, Hoang MP. Spitz nevi and atypical Spitz nevi/tumors: a histologic and immunohistochemical analysis. Mod Pathol. Feb 2005;18(2):197-204. [Medline].
Orchard DC, Dowling JP, Kelly JW. Spitz naevi misdiagnosed histologically as melanoma: prevalence and clinical profile. Australas J Dermatol. Feb 1997;38(1):12-4. [Medline].
Rapini RP. Spitz nevus or melanoma?. Semin Cutan Med Surg. Mar 1999;18(1):56-63. [Medline].
Shimek CM, Golitz LE. The golden anniversary of the Spitz nevus. Arch Dermatol. Mar 1999;135(3):333-5. [Medline].
Song JY, Kwon JA, Park CJ. A case of Spitz nevus with multiple satellite lesions. J Am Acad Dermatol. Feb 2005;52(2 Suppl 1):48-50. [Medline].
Spatz A, Calonje E, Handfield-Jones S, Barnhill RL. Spitz tumors in children: a grading system for risk stratification. Arch Dermatol. Mar 1999;135(3):282-5. [Medline].
Urso C, Borgognoni L, Saieva C, et al. Sentinel lymph node biopsy in patients with "atypical Spitz tumors." A report on 12 cases. Hum Pathol. Jul 2006;37(7):816-23. [Medline].
Vollmer RT. Patient age in Spitz nevus and malignant melanoma: implication of Bayes rule for differential diagnosis. Am J Clin Pathol. Jun 2004;121(6):872-7. [Medline].
Vollmer RT. Use of Bayes rule and MIB-1 proliferation index to discriminate Spitz nevus from malignant melanoma. Am J Clin Pathol. Oct 2004;122(4):499-505. [Medline].
Weedon D, Little JH. Spindle and epithelioid cell nevi in children and adults. A review of 211 cases of the Spitz nevus. Cancer. Jul 1977;40(1):217-25. [Medline].
Zaenglein AL, Heintz P, Kamino H, Zisblatt M, Orlow SJ. Congenital Spitz nevus clinically mimicking melanoma. J Am Acad Dermatol. Sep 2002;47(3):441-4. [Medline].
Zatterstrom U, Thor A, Nordgren H. Cervical metastasis from Spitz nevus of the buccal mucosa. Melanoma Res. Feb 2008;18(1):36-9. [Medline].

