Cutaneous Melanomas Arising during Childhood: An Overview of the Main Entities

Cutaneous melanomas are exceptional in children and represent a variety of clinical situations, each with a different prognosis. In congenital nevi, the risk of transformation is correlated with the size of the nevus. The most frequent type is lateral transformation, extremely rare before puberty, reminiscent of a superficial spreading melanoma (SSM) ex-nevus. Deep nodular transformation is much rarer, can occur before puberty, and must be distinguished from benign proliferative nodules. Superficial spreading melanoma can also arise within small nevi, which were not visible at birth, usually after puberty, and can reveal a cancer predisposition syndrome (CDKN2A or CDK4 germline mutations). Prognosis is correlated with classical histoprognostic features (mainly Breslow thickness). Spitz tumors are frequent in adolescents and encompass benign (Spitz nevus), intermediate (atypical Spitz tumor), and malignant forms (malignant Spitz tumor). The whole spectrum is characterized by specific morphology with spindled and epithelioid cells, genetic features, and an overall favorable outcome even if a regional lymph node is involved. Nevoid melanomas are rare and difficult to diagnose clinically and histologically. They can arise in late adolescence. Their prognosis is currently not very well ascertained. A small group of melanomas remains unclassified after histological and molecular assessment.

Evolution of superficial spreading melanoma to resemble desmoplastic melanoma: case report

Desmoplastic melanoma commonly occurs on the head and neck in a pure form, but occasionally, it occurs in a mixed tumor with another type, usually superficial spreading melanoma (SSM), and rarely as a metastasis from a primary SSM. We report here a primary SSM on the leg of a 32-year-old male which metastasised to lymph nodes, and 10 years later recurred at the primary site initially with mixed features but evolving to resemble a uniformly desmoplastic, deeply invasive melanoma. This unusual case has implications for clinical management and is additionally notable for its reversal in behavior, from metastatic to local infiltrative type, correlating with the change in morphology.

Caucasians with acral lentiginous melanoma have the same outcome as patients with stage- and limb-matched superficial spreading melanoma

Purpose Acral lentiginous melanoma (ALM), a relatively rare subtype of cutaneous melanoma, has been reported to have a worse prognosis than other melanomas. We aimed to assess clinical findings in Caucasian ALM patients and compare the data with a matched cohort of superficial spreading melanoma (SSM) patients. Methods We studied 63 patients with ALM and 63 randomly stage- and limb-matched patients with SSM (non-ALM). In both cohorts, guideline-adjusted diagnosis, treatment and follow-up were performed. Results We did not observe differences in prognostic factors (e.g., tumor thickness, ulceration) between the two cohorts. Both in ALM and non-ALM patients positive sentinel lymph node was a significant independent predictor for disease relapse and melanoma-specific death. However, disease relapse and melanoma-specific death rates did not significantly differ between ALM and non-ALM patients. An overall 5-year melanoma-specific survival of 82.5% and 81% was observed in ALM and non-ALM patients, respectively. Conclusions Our data confirm that patients with ALM have no worse outcome than non-ALM patients when correcting for significant prognostic factors. Hence, the reportedly high rates of fatal ALM cases should not be ascribed to pathobiological differences between ALM and non-ALM but are most likely are a consequence of a delay in diagnosis and thus advanced stage of ALM.