Melanoma diagnosis at a specialist dermatology practice without the use of photographic surveillance

BACKGROUND/OBJECTIVE

Photographic aides are increasingly used in melanoma surveillance. We report melanoma characteristics detected using traditional surveillance without photographic technologies.

METHODS

Retrospective study of melanomas diagnosed by three dermatologists at a private dermatology practice over 7 years. Patients underwent full skin examinations with dermoscopy and suspect lesions were excised or biopsied. Total body photography (TBP) and serial digital dermoscopic imaging (SDDI) were not used. Patient demographics, melanoma subtype and thickness, location, biopsy technique and keratinocyte cancers diagnosed at the same visit were recorded. Ratio of in situ to invasive melanomas was calculated. Melanoma risk factors were recorded for 69 randomly-selected patients.

RESULTS

492 patients were diagnosed with 615 melanomas during 579 visits. 505 (82%) were in situ (in situ to invasive ratio of 4.6:1). Of the invasive melanomas, 85.5% had a Breslow thickness <0.8 mm, 10 (9.1%) 0.8-1 mm and 6 (5.5%) >1 mm. 43.3% of in situ melanomas were lentiginous or lentigo maligna and 41.6% were superficial spreading melanomas (SSM). Of invasive melanomas, 24.3% were lentigo maligna melanoma and 59.5% were SSM. 48.4% of melanomas were diagnosed by shave procedures. Where risk factors were known, 25% were very-high-risk and 43% had a history of melanoma. Keratinocyte carcinoma was diagnosed by biopsy at 26.1% of visits. Studies using TBP and/or SDDI report in situ to invasive ratios of 0.59:1 to 2.17:1.

CONCLUSION

Tradiational melanoma surveillance with immediate biopsy of suspect lesions results in high in situ to invasive ratios. Studies using photographic surveillance show lower ratios of in situ to invasive disease.

Percutaneous contrast-enhanced ultrasound for localization and qualitative diagnosis of sentinel lymph nodes in cutaneous malignant melanoma of lower extremities: a preliminary study

Background

To explore the feasibility of sentinel lymph node (SLN) tracing by percutaneous contrast-enhanced ultrasound (pCEUS) in patients with cutaneous malignant melanoma (CMM) and the ability to enhance patterns of SLNs in diagnosing lymph nodes (LNs) metastases.

Methods

Fifty-three patients with CMM of the lower extremities treated at our hospital were included in the study. All the participants received pCEUS preoperatively. The enhanced lymphatic channels (LCs) and associated SLNs were observed and tracked in real-time. The number of enhanced LCs and enhancing patterns of SLNs were recorded. Subsequently, SLNs localized by pCEUS were pathologically examined.

Results

Of the 53 cases, SLNs were successfully localized by pCEUS in 48 cases. In total, there were 59 detected SLNs averaging 1.23±0.42 SLNs per case. The main lymphatic drainage patterns (LDPs) were the following: one enhanced LC pointed to one or more than one SLN, and multiple enhanced LCs pointed to one or multiple SLNs. There were four enhancing patterns of SLNs (uniform, annular, uneven, and no enhancement), among which the first two were considered benign nodes, while the latter two were considered metastatic nodes. With pathological results as the gold standard, the diagnostic sensitivity and specificity by pCEUS were 90.9% and 75.0%, respectively.

Conclusions

Contrast-enhanced ultrasound (US) is a feasible approach for SLN identification in patients with CMM of the lower extremities. Enhancing patterns of SLNs may help predict metastasizing SLNs. This novel method may be a promising technique for clinical application.

IMP dehydrogenase rod/ring structures in acral melanomas

Acral lentiginous melanoma (ALM) is a rare subtype of melanoma with aggressive behavior. IMPDH enzyme, involved in de novo GTP biosynthesis, has been reported to assemble into large filamentary structures called rods/rings (RR) or cytoophidium (cellular snakes). RR assembly induces a hyperactive state in IMPDH, usually to supply a high demand for GTP nucleotides, such as in highly proliferative cells. We investigate whether aggressive melanoma tumor cells present IMPDH-based RR structures. Forty-five ALM paraffin-embedded tissue samples and 59 melanocytic nevi were probed with anti-IMPDH2 antibody. Both the rod- and ring-shaped RR could be observed, with higher frequency in ALM. ROC curve analyzing the proportions of RR-positive cells in ALM versus nevi yielded a 0.88 AUC. Using the cutoff of 5.5% RR-positive cells, there was a sensitivity of 80% and specificity of 85% for ALM diagnosis. In ALM, 36 (80%) showed RR frequency above the cutoff, being classified as RR-positive, compared with only 9 (15%) of the nevi (p < .001). Histopathology showed that 71% of the RR-positive specimens presented Breslow thickness > 4.0mm, compared with only 29% in the RR-low/negative (p = .039). We propose that screening for RR structures in biopsy specimens may be a valuable tool helping differentiate ALM from nevi and accessing tumor malignancy.

Treating malignant melanoma when a rare BRAF V600M mutation is present: case report and literature review

Recent years have brought major advances in the treatment of malignant melanoma. One such an advance is the treatment with BRAF tyrosine-kinase inhibitors in metastatic malignant melanomas that harbor mutations in the BRAF gene. The trials that have been performed in this setting have demonstrated superior response rates and increased overall survival, however, they mostly included patients with melanomas carrying the more common V600E and V600K mutations, not being able to assess the benefit of these treatments in situations where more rare mutations of the BRAF gene are present. We present the evolution of a patient with malignant melanoma with a rare V600M mutation in the BRAF gene, that was eventually treated with vemurafenib. Also we present a brief review of the major phase III trials that showed benefit with tyrosine-kinase inhibitors in BRAF mutated melanoma, with respect to the BRAF mutations included.