For each major diagnostic category of histologically ambiguous lesion (spitzoid tumors, lesions raising a differential diagnosis of an atypical nevus versus nevoid melanoma, and dysplastic nevus versus superficial spreading melanoma), Table 1 shows the initial MelanoSITE results and the final FISH result interpretation after correcting for false-positive results.
Subset Tetraploidy Final FISH Interpretation Spitzoid tumor 4 (29) 10 (19) Favor benign 2 (100) 0 (0) Borderline 1 (12) 8 (29) Favor 1 (25) 3 (60) melanoma Atypical nevus 5 (36) 9 (17) versus nevoid melanoma Favor benign 2 (50)b 0b (0) Borderline 2 (20) 6 (40) Favor 0 (0) 2 (29) melanoma Dysplastic 2 (20) 8 (24) nevus versus melanoma Favor benign 1 (100) 0 (0) Borderline 1 (25) 1 (25) Favor 0 (0) 7 (54) melanoma Suspected 0 (0) 1 (50) desmoplastic melanoma Total 10 (26) 29 (21) (a) The table summarizes MelanoSITE FISH results for each histologic diagnostic category (Spitzoid tumor, atypical nevus versus nevoid melanoma, dysplastic nevus versus melanoma, and suspected desmoplastic melanoma) and their subsets (favor benign, borderline, and favor melanoma).
Dysplastic nevus syndrome: a phenotypic association of sporadic cutaneous melanoma.
Recurrent dysplastic nevus following shave excision.
Papillary dermal fibrosis is absent or only slight, and lamellar fibroplasias or concentric eosinophilic fibrosis, typical of a dysplastic nevus, is absent.
The unique clinical and histologic features discussed above and summarized in Table 2 suggest that lentiginous melanoma represents a distinct clinicopathologic entity from a common lentiginous nevus, dysplastic nevus, superficial spreading melanoma, and lentigo maligna.
Atypical lentiginous melanocytic proliferations in elderly patients continue to pose a diagnostic dilemma, with lesions variably categorized as dysplastic nevus, atypical junctional nevus, melanoma in situ (early or evolving), and premalignant melanosis.
Cytogenetic analysis of conjunctival melanoma in a patient with dysplastic nevus syndrome revealed a clonal 1;14 translocation.
Prevalence of primary acquired melanosis and nevi of the conjunctiva and uvea in the dysplastic nevus syndrome: a case-control study.
Conjunctival and uveal melanoma in the dysplastic nevus syndrome.
Slide 2 Slide 3 11 AK SCC in situ 29 Trichilemmoma Trichilemmoma 63 SCC SCC 72 AK SCC in situ 84 BCC BCC 95 Nevus Nevus 147 SCC in situ SCC in situ 203 Nevus Dysplastic nevus
215 BCC BCC 279 Dysplastic nevus Dysplastic nevus
(severe) 306 Hemangioma Hemangioma 310 Nevus Nevus 395 SCC in situ SCC in situ 459 BCC BCC 464 SCC in situ SCC in situ * AK indicates actinic keratosis; SCC, squamous cell carcinoma; SK, seborrheic keratosis; and BCC, basal cell carcinoma.
Allelic deletion at chromosome 9p21(p16) and 17p13(p53) in microdissected sporadic dysplastic nevus