Spindle and epithelioid cell nevi in children and adults.A review of 211 cases of the spitz nevus

Abstract

A large series of 211 Spitz nevi is reviewed. 30% of the lesions were from patients 20 years of age and over. The trunk and lower extremity were most commonly involved. There were no significant histologic differences between cases from adults and children. Features which may help in differentiating atypical Spitz nevi from malignant melanoma include the presence of some nevus cell maturity at the base, an absence of atypical mitoses, no significant upward epidermal spread and the nuclear chromatin pattern.

Sentinel lymph node biopsy for patients with problematic spitzoid melanocytic lesions

“…Piepkorn cites as worrisome findings high-grade nuclear atypia, high mitotic rate with deep dermal mitoses or atypical mitoses, no or only focal maturation at the base, deep penetration into lower dermis or subcutis, ulceration, and large lesional size. 20 Other authors have cited similar criteria, as well as other criteria, for the diagnosis of Spitz-like melanoma, such as marked pagetoid spread, 26 singlecell epidermal invasion below parakeratosis, 27 asymmetry, 5 destruction of collagen, 3 substantial and/or deep melanization, 21 and variability of cellular features between adjacent cell groups. 4 Reed proposed that confluent or expansile, nodular aggregates of atypical Spitz-like cells in the dermis represent a vertical growth phase or possess a competence for metastasis and are regarded best as minimal deviation melanoma, Spitz-like type.…”

“…2 Although most spindle and epithelioid melanocytic proliferations readily are classifiable histologically as Spitz nevus or melanoma with Spitz-like features, 1,[3][4][5] there is a subset of problematic and diagnostically challenging melanocytic lesions variably designated as atypical Spitz tumor, atypical Spitz nevus, Spitz-like lesion in the borderline category of indeterminate malignant potential, and diagnostically controversial spitzoid melanocytic tumors, that defy classification into either category even by the most experienced dermatopathologists. 2,6 -10 These lesions simultaneously exhibit some histomorphologic features of classic Spitz nevus and Spitz-like melanoma, making diagnostic assignment to either Spitz nevus or Spitz-like melanoma difficult, controversial, and sometimes erroneous.…”

The Spitzoid lesion: rethinking Spitz tumors, atypical variants, ‘Spitzoid melanoma' and risk assessment

“…As we have described various authors have reviewed their own series of 'Spitz nevi' and accordingly formulated their 'criteria' from these self-selected (and consequently biased) series of lesions (Table 2). 7,11,12,26 The inherent flaws resulting from this exercise involve circular reasoning, the cases in general have not been population-based, the number of cases has often not been adequate, and the cases have not had long-term follow-up (of 8-10 years) to know the outcomes. 22,25,26 Following up on the observations that the vast majority of these Spitzoid lesions do not seem to recur or to metastasize, they have been lumped as a group in benign melanocytic nevi, even though some proportion of lesions seem impossible to distinguish from melanoma and uncommon or rare lesions behave aggressively.…”

BRAF and NRAS mutations in spitzoid melanocytic lesions

“…The spitzoid lesions were independently reviewed by three board certified dermatopathologists (LL, LDS, and DRF) with diagnostic expertise in pigmented lesions and who are members of the Multidisciplinary Melanoma Clinic at the University of Michigan. Of the 48 Spitz nevi, 21 were classic Spitz nevi, on the basis of previously published criteria, 6,7 and two were desmoplastic Spitz nevi. The remaining 25 Spitz nevi demonstrated some atypical features, such as architectural disorder, increased cytologic atypia and/or inflammation.…”

“…3,4 Fortunately, most spitzoid lesions can be classified into benign Spitz nevi or Spitz-like melanomas based on published criteria. [5][6][7][8][9][10][11][12][13][14][15] However, a subset of spitzoid lesions remain that have histologic features that deviate from a typical Spitz nevus, yet are insufficient for a definitive diagnosis of Spitzlike melanoma. These atypical spitzoid lesions have been referred to variously in the literature as borderline and intermediate melanocytic neoplasia, minimal-deviation melanoma, nevoid melanoma, atypical Spitz nevus/tumor, malignant Spitz nevus, problematic Spitzoid melanocytic lesions, and diagnostically controversial Spitzoid melanocytic tumors.…”