Please login or create an account. If you do not have access to this content, you will be shown a 30 second preview and licensing options.

Presentation

Clinicopathologic Self-Assessment: Diagnosis and Management of Melanocytic Tumors

Description

The presentation focuses on two distinct cases related to dermatological conditions and their underlying pathologies. In the first case, a 24-year-old patient presented with a suspected dermatofibroma, but after biopsy findings indicated a pigmented lesion with atypical characteristics, molecular testing was performed. This led to the consensus diagnosis of a Spitz melanoma, supported by chromosomal abnormalities indicating malignancy. The session emphasized the importance of chromosomal microarrays and next-generation sequencing in distinguishing melanocytic lesions to guide treatment. The second case involved an elderly male patient with acute generalized itching and eruptive lesions attributed to potential drug reactions or autoimmune disorders. Biopsies revealed eosinophilic infiltration and blistering, typically associated with bullous pemphigoid. However, further analysis revealed a dermal pattern indicating a rarer variant that required extensive serological tests to confirm the diagnosis, ultimately identifying the condition as P200 pemphigoid. The speaker underscored the importance of thorough diagnostic testing, especially in complex cases, highlighting nutritional deficiencies such as vitamin C and zinc deficiency, which can present similarly to autoimmune dermatoses. These cases illustrate the complexities and nuances of dermatopathology, emphasizing the need for careful clinical and histological correlations to arrive at an accurate diagnosis.

View more

Conclusions

The diagnostic process for pigmented lesions can lead to different results based on varying histopathological interpretations.
In cases of atypical Spitz tumors, molecular testing like chromosomal microarrays can provide critical information for accurate diagnosis.
The presence of three or more chromosomal abnormalities is a significant indicator of melanoma risk, guiding treatment options.
A diagnosis of Spitz melanoma was confirmed based on morphological and molecular criteria, including Breslow thickness measuring at least 0.6 mm.
Clinical presentation, such as generalized pruritus and specific lesion types, can indicate underlying autoimmune conditions like bullous pemphigoid.
Direct immunofluorescence testing is essential in diagnosing subepidermal blistering disorders and differentiating between various forms of pemphigoid.
Zinc deficiency can present with distinctive bullous skin symptoms and should be considered in patients with relevant dietary histories and gastrointestinal illnesses.
Early diagnosis and treatment of zinc deficiency through supplementation can lead to rapid improvement of skin lesions.
Vitamin C deficiency, although rare, can lead to significant skin and systemic symptoms and should not be overlooked in patients with malabsorption syndromes.

Tetzlaff M, et al. Toward a molecular-genetic classification of Spitzoid neoplasms. Clin Lab Med 2017; 37: 431-448.
Fujimoto M, et al. A case report of atypical Spitz tumor harboring a novel MLPH-ALK gene fusion with discordant ALK immunohistochemistry results. Hum Pathol 2018; 80: 99-103.
Saraggi D, et al. Prevalence of ALK gene alterations among the spectrum of plexiform spitzoid lesions. J Am Acad Dermatol 2018; 79: 728-735.
Rand AJ, et al. Atypical ALK-positive Spitz tumors with 9p21 homozygous deletion: Report of two cases and review of the literature. J Cutan Pathol 2018; 45: 136-140.
Shalin SC. A review of kinase fusions in melanocytic tumors. Lab Invest 2017; 97: 158-165.
Kim et al. BRAF fusion Spitz neoplasms: clinical, morphologic, and genomic findings in 6 cases. J Cutan Pathol. 2020; 47: 1132-1142.
Alomari AK, Miedema JR, Carter MD, et al. DNA copy number changes correlate with clinical behavior in melanocytic neoplasms: proposal of an algorithmic approach. Mod Pathol. 2020 Jul;33(7):1307-1317. doi: 10.1038/s41379-020-0499-y. Epub 2020 Feb 17. PMID: 32066860.
Andea AA. Molecular testing for melanocytic tumors: a practical update. Histopathology. 2022 Jan;80(1):150-165. doi: 10.1111/his.14570. PMID: 34958511.