Punch 'scoring': a technique that facilitates melanoma diagnosis of clinically suspicious pigmented lesions

Impact of Clinical Information on Melanocytic Skin Lesion Pathology Diagnosis: A Scoping Review

Importance

There is poor accuracy and reproducibility for the histopathologic diagnosis of melanocytic skin lesions, and the provision of clinical information may improve this.

Objective

To examine the impact of clinical information on the histopathologic diagnosis of melanocytic skin lesions.

Evidence Review

PubMed, Embase, and Cochrane Library were searched for new records published from January 2018 to January 2024. References included in the 2018 Cancer Council Australia evidence review were also screened, and forward and backward citation searches were conducted.

Findings

From 2224 records screened, 162 full-text studies were assessed, and 7 studies were included. Studies included pathologists from Austria, Germany, the US, Italy, the UK, and Australia. Patient populations had a mean age of 43 to 55 years and a proportion of female participants of 23% to 63%. The risk of bias assessment demonstrated that all studies had domains at unclear or high risk of bias. Clinical images increased diagnostic certainty (3 studies) and agreement between pathologists (2 studies) led to diagnostic upgrades in 7.6% to 16.7% of interpretations. Clinical diagnosis on the pathology requisition form reduced the odds of missing a melanoma with progression (1 study), while more clinical elements on the form correlated with higher re-excision rates (1 study). Among patients with distant metastases on long-term follow-up, a prior consensus diagnosis of melanoma was established on histopathology alone.

Conclusions and Relevance

Providing clinical information to pathologists may improve diagnostic confidence and interobserver agreement and result in upgrading of the histopathologic diagnosis. While providing the clinical diagnosis may prevent missing a progressive melanoma, more research is needed to determine the appropriateness of histopathology upgrading when clinical images are provided and the impacts on patient outcomes.

Short-Term Lesion Change Detection for Melanoma Screening With Novel Siamese Neural Network

Short-term monitoring of lesion changes has been a widely accepted clinical guideline for melanoma screening. When there is a significant change of a melanocytic lesion at three months, the lesion will be excised to exclude melanoma. However, the decision on change or no-change heavily depends on the experience and bias of individual clinicians, which is subjective. For the first time, a novel deep learning based method is developed in this paper for automatically detecting short-term lesion changes in melanoma screening. The lesion change detection is formulated as a task measuring the similarity between two dermoscopy images taken for a lesion in a short time-frame, and a novel Siamese structure based deep network is proposed to produce the decision: changed (i.e. not similar) or unchanged (i.e. similar enough). Under the Siamese framework, a novel structure, namely Tensorial Regression Process, is proposed to extract the global features of lesion images, in addition to deep convolutional features. In order to mimic the decision-making process of clinicians who often focus more on regions with specific patterns when comparing a pair of lesion images, a segmentation loss (SegLoss) is further devised and incorporated into the proposed network as a regularization term. To evaluate the proposed method, an in-house dataset with 1,000 pairs of lesion images taken in a short time-frame at a clinical melanoma centre was established. Experimental results on this first-of-a-kind large dataset indicate that the proposed model is promising in detecting the short-term lesion change for objective melanoma screening.

Melanoma pathology reporting and staging

The pathological diagnosis of melanoma can be challenging. The provision of an appropriate biopsy and pertinent history can assist in establishing an accurate diagnosis and reliable estimate of prognosis. In their reports, pathologists should document both the criteria on which the diagnosis was based as well as important prognostic parameters. For melanoma, such prognostic parameters include tumor thickness, ulceration, mitotic rate, lymphovascular invasion, neurotropism, and tumor-infiltrating lymphocytes. Disease staging is important for risk stratifying melanoma patients into prognostic groups and patient management recommendations are often stage based. The 8th edition American Joint Committee on Cancer (AJCC) Melanoma Staging System was implemented in 2018 and several important changes were made. Tumor thickness and ulceration remain the key T category criteria. T1b melanomas were redefined as either ulcerated melanomas <1.0 mm thick or nonulcerated melanomas 0.8-1.0 mm thick. Although mitotic rate was removed as a T category criterion in the 8th edition, it remains a very important prognostic factor and should continue to be documented in primary melanoma pathology reports. It was also recommended in the 8th edition that tumor thickness be recorded to the nearest 0.1 mm (rather than the nearest 0.01 mm). In the future, incorporation of additional prognostic parameters beyond those utilized in the current version of the staging system into (web based) prognostic models/clinical tools will likely facilitate more personalized prognostic estimates. Evaluation of molecular markers of prognosis is an active area of current research; however, additional data are needed before it would be appropriate to recommend use of such tests in routine clinical practice.

From Breslow to BRAF and immunotherapy: evolving concepts in melanoma pathogenesis and disease progression and their implications for changing management over the last 50 years

Since it was first recognized as a disease entity more than two centuries ago, advanced melanoma has, until recently, followed a very aggressive and almost universally fatal clinical course. However, over the past 50 years crucial ground breaking research has greatly enhanced our understanding of the etiology, risk factors, genomic pathogenesis, immunological interactions, prognostic features and management of melanoma. It is this combined body of work which has culminated in the exciting improvements in patient outcomes for those with advanced melanoma over the last ten years. In this the 50th anniversary of Human Pathology, we highlight the key developments in melanoma over this period.