Synchronous primary cutaneous melanomas: a descriptive study of their clinical features, histology, genetic background of the patients and clinical outcomes

Diagnostic utility of the 23-gene expression profile test for an atypical intradermal melanocytic proliferation

Ancillary tests such as immunohistochemistry (IHC) and gene expression profile (GEP) testing may be needed to arrive at a definitive diagnosis for some atypical melanocytic neoplasms. A 34-year-old male with a family history of melanoma presented with a large, heterogeneous melanocytic lesion on the cheek. Histopathological review of two biopsies revealed an atypical intradermal melanocytic proliferation with spitzoid features without ulceration or regression. Scattered mitotic figures were identified. In addition to performing SOX10 IHC, PRAME and HMB45 staining highlighted weak, patchy positivity that was stronger in superficial, pleomorphic melanocytes (Ki-67, 5-7% mitotic rate). Based on these concerning but ambiguous IHC results and lingering concern for melanoma reiterated by other consulting dermatopathologists, the 23-GEP was requested for both specimens, which both returned a malignant result. The inconclusive histopathological features of malignancy were resolved by 23-GEP testing, facilitating a final diagnosis of malignant melanoma (pT3a, 2.5 mm Breslow depth, Clark's level IV).

Multiple Primary Melanoma: A Five-Year Prospective Single-Center Follow-Up Study of Two MC1R R/R Genotype Carriers

BACKGROUND

Multiple primary melanoma (MPM) is a diagnostic challenge even with ancillary imaging technologies available to dermatologists. In selected patients' phenotypes, the use of imaging approaches can help better understand lesion characteristics, and aid in early diagnosis and management.

METHODS

Under a 5-year prospective single-center follow-up, 58 s primary melanomas (SPMs) were diagnosed in two first-degree relatives, with fair skin color, red hair, green eyes, and personal history of one previous melanoma each. Patients' behavior and descriptive demographic data were collected from medical records. The information on the first two primary melanomas (PMs) were retrieved from pathology reports. The characteristics of 60 melanomas were collected from medical records, video dermoscopy software, and pathology reports. Reflectance confocal microscopy (RCM) was performed prior to excision of 22 randomly selected melanomas.

RESULTS

From February 2018 to May 2023, two patients underwent a pooled total of 214 excisional biopsies of suspect lesions, resulting in a combined benign versus malignant treatment ratio (NNT) of 2.0:1.0. The number of moles excised for each melanoma diagnosed (NNE) was 1.7:1.0 and 6.9:1.0 for the female and male patient respectively. The in-situ melanoma/invasive melanoma ratio (IIR) demonstrated a higher proportion of in-situ melanomas for both patients. From June 2018 to May 2023, a total of 58 SPMs were detected by the combination of total body skin exam (TBSE), total body skin photography (TBSP), digital dermoscopy (DD), and sequential digital dermoscopy imaging (SDDI) via comparative approach. The younger patient had her PM one month prior to the second and third cutaneous melanomas (CMs), characterizing a case of synchronous primary CM. The male older relative had a total of 7 nonsynchronous melanomas.

CONCLUSIONS

This CM cohort is composed of 83.3% in-situ melanoma and 16.7% invasive melanoma. Both patients had a higher percentage of SPM with clinical nevus-like morphology (84.5%), global dermoscopic pattern of asymmetric multiple component (60.3%) and located on the lower limbs (46.6%). When RCM was performed prior to excision, 81% of SPM had features suggestive of malignancy. As well, invasive melanomas were more frequent in the lower limbs (40%). In the multivariate model, for the two high-risk patients studied, the chance of a not associated with nevus ("de novo") invasive SPM diagnosis is 25 times greater than the chance of a diagnosis of a nevus-associated invasive SPM.

Synchronous Melanoma: Definition, Prognosis, and Implications. A Comprehensive Review of Literature

Background

Although multiple primary melanomas (MPMs) have been reported in the literature, the subgroup of synchronous melanomas (SMs) remains understudied.

Methods

We conducted a comprehensive systematic review of the English literature from 1972 to 2023 to characterize SM. Our objective was to clarify the definition, determine incidence and prognosis, and present recommendations.

Results

We found 18 case series articles and six case reports that met our criteria. Twelve of eighteen studies defined SM as a second primary melanoma identified within 1 month. The total number of SM patients reported was 1083. The cumulative percentage of MPM in total melanoma patients was 2.9 %, and the cumulative percentage of SM patients in MPM patients was 31.3%. SM patients trended toward higher body anatomical concordance, older age, and male sex. Despite limited data, SMs do not show a worse prognosis for patients compared with single melanomas.

Conclusions

Despite a lack of consensus in the past, we recommend that SM be defined as a second primary melanoma detected within 1 month of the initial diagnosis. SMs comprise almost one-third of MPM cases and do not seem to carry any worse prognosis than the patients presenting with single melanoma. We believe older age and male sex may be more prone to SM. We recommend patient education, self-skin evaluations and TSE at initial and follow-up visits. Neither randomized controlled trials nor meta-analyses on SM exist. Ideally, further studies with a large cohort of patients are needed to accurately define SM.