Expression of microphthalmia transcription factor, S100 protein, and HMB-45 in malignant melanoma and pigmented nevi

Primary thoracolumbar intraspinal malignant melanoma: A case report

BACKGROUND

Primary intraspinal malignant melanoma is a very rare tumor that most often occurs in the cervical, thoracic, or thoracolumbar segment.

CASE SUMMARY

A rare case of primary thoracolumbar malignant melanoma is described. A 45-year-old female patient complained of low back pain with numbness and fatigue in both lower limbs. MR revealed an intradural space-occupying lesion at the thoracic 12 to lumbar 1 level. The tumor was partially excised, and a malignant melanoma was confirmed by histopathology.

CONCLUSION

Primary intraspinal malignant melanoma has rarely been reported, and surgical resection and related characteristics and diagnoses have been discussed.

Cutaneous Melanoma: A Review of Multifactorial Pathogenesis, Immunohistochemistry, and Emerging Biomarkers for Early Detection and Management

Cutaneous melanoma (CM) is an increasingly significant public health concern. Due to alarming mortality rates and escalating incidence, it is crucial to understand its etiology and identify emerging biomarkers for improved diagnosis and treatment strategies. This review aims to provide a comprehensive overview of the multifactorial etiology of CM, underscore the importance of early detection, discuss the molecular mechanisms behind melanoma development and progression, and shed light on the role of the potential biomarkers in diagnosis and treatment. The pathogenesis of CM involves a complex interplay of genetic predispositions and environmental exposures, ultraviolet radiation exposure being the predominant environmental risk factor. The emergence of new biomarkers, such as novel immunohistochemical markers, gene mutation analysis, microRNA, and exosome protein expressions, holds promise for improved early detection, and prognostic and personalized therapeutic strategies.

The Importance of Immunohistochemistry in the Evaluation of Tumor Depth of Primary Cutaneous Melanoma

Primary cutaneous melanoma (PCM) is the most aggressive skin malignancy, with an increasing incidence and significant mortality. Tumoral invasion, expressed as Breslow thickness, is routinely assessed on hematoxylin and eosin (HE), although this stain may sometimes underestimate the tumoral depth. The aim of this study was to compare the efficiency of the immunohistochemical (IHC) markers S-100, SOX10, Melan-A, and HMB-45 with HE for the evaluation of the Breslow thickness and staging of PCM. This retrospective study included 46 cases of PCM diagnosed between 2015 and 2022; for each case, the Breslow thickness using HE, S-100, SOX10, Melan-A, and HMB-45 was measured and the appropriate T category was recorded. The highest values of the Breslow thickness were observed for S-100. However, S-100, SOX10, and Melan-A provided statistically significant higher values of the Breslow thickness compared to HE, but no difference was noted between HMB-45 and HE. S-100 was most frequently involved in increasing the T category (26.1%), the majority of cases being upstaged from T1a to T1b. The IHC markers S-100, SOX10, and Melan-A contributed to better evaluation of the melanoma invasion, especially in thin melanomas, but their impact on staging and consecutive treatment remains to be confirmed by future studies.

Clinical and immunohistochemical analysis of the verrucous and non-verrucous divided nevus of the eyelids

Purpose

Divided nevus with verrucous hyperplasia will always recur after surgery but non-verrucous divided eyelid nevus rarely recur. This study analyzed the differential expression of Ki-67, S100, Melan A and HMB45 and identified the correlation between the clinical and histopathological features of verrucous and non-verrucous divided eyelid nevus.

Methods

This study included 29 patients, of whom 8 patients had verrucous divided nevus. Immunohistochemistry labeling was used to assess the expression of Ki-67, S100, Melan A and HMB45 after excision. The difference between verrucous and non-verrucous divided eyelid nevus was analyzed.

Results

The patients’ ages ranged from 2 to 59 years, with a mean age of 19 years. The lesion size ranged from 1.5 to 2.0 cm in diameter and invaded the eyelid margins and the posterior lamella of the eyelids. Immunohistochemistry labeling showed strong positivity for approximately 98.5% of S100 and positive staining for approximately 27.6% of Ki-67, 72.4% of Melan A and 6.8% of HMB45. However, Ki-67 was significantly upregulated in verrucous divided nevus of the eyelids compared with non-verrucous divided nevus, with approximately 38.8% upregulation in verrucous and 18.3% upregulation in non-verrucous nevus.

Conclusions

This study correlated the clinic-pathologic features of verrucous divided eyelid nevus by means of statistically analyzing the varied clinical features and pathological impressions. The significant over-expression of S100 may be used as an indicator of divided nevus of the eyelids, and the over-expressed Ki-67 may contribute to the recurrence of verrucous divided nevus. High expression of HMB45 and Melan A may represent malignant transformation.

Primary intramedullary melanoma of lumbar spinal cord: A case report

BACKGROUND

Primary intramedullary melanoma is a very rare tumor, most frequently occurring in the cervical and thoracic spinal cord.

CASE SUMMARY

We present a rare case in which the primary intramedullary melanoma was located in the lumbar spine. A 56-year-old man complained of progressive intermittent pain in the lumbar area. Thoracic magnetic resonance imaging showed a spinal intramedullary tumor between the L3 and S1 levels. The tumor was resected entirely, and the diagnosis of malignant melanoma was confirmed by histopathology.

CONCLUSION

Primary melanoma of the spinal cord, particularly intramedullary localization, has rarely been reported in the previous literature. We describe a primary malignant melanoma of the lumbar spinal cord and discuss the challenges associated with the diagnosis.

Immunohistochemical Staining in the Assessment of Melanoma Tumor Thickness

Vertical tumor thickness has great influence in the prognosis and staging of melanoma. The aim of this study was determination of the differences between melanoma tumor thickness in conventional hematoxylin and eosin (H&E) and immunohistochemical techniques. Thirty-six biopsy specimens were included in our study. For each sample, four adjacent tissue sections were stained with H&E, in addition S-100, Melan- A and HMB-45 staining was performed on the next serial sections. The mean thickness of tumor invasion was 2.16, 2.38, 2.22 and 2.29 mm in H&E, S-100, HMB45 and Melan-A sections evaluation, respectively. The mean difference of the Breslow thickness between H&E and S-100 and also, between H&E and Melan-A stained slides were statistically significant (p˂0.05) while no difference was found in the tumor thickness of the H&E and HMB45 staining evaluation (p = 0.278). Greater tumor thickness was observed in 25 lesions (69.4%) with S-100, 20 lesions (55.5%) with Melan-A and 17 (47.2%) lesions in HMB-45 rather than H&E staining. Conclusively, it appears that H&E staining cannot prove the actual size of melanoma invasion in some cases and immunohistochemical examination can be a complementary method in this situations. Of the melanoma associated immunomarkers, the combination of S-100 and Melan-A staining may suffice to measure depth of tumor invasion.

Melanoma-Bearing Libechov Minipig (MeLiM): The Unique Swine Model of Hereditary Metastatic Melanoma

National cancer databases document that melanoma is the most aggressive and deadly cutaneous malignancy with worldwide increasing incidence in the Caucasian population. Around 10% of melanomas occur in families. Several germline mutations were identified that might help to indicate individuals at risk for preventive interventions and early disease detection. More than 50% of sporadic melanomas carry mutations in Ras/Raf/mitogen-activated protein kinase (MAPK/MEK) pathway, which may represent aims of novel targeted therapies. Despite advances in targeted therapies and immunotherapies, the outcomes in metastatic tumor are still unsatisfactory. Here, we review animal models that help our understanding of melanoma development and treatment, including non-vertebrate, mouse, swine, and other mammal models, with an emphasis on those with spontaneously developing melanoma. Special attention is paid to the melanoma-bearing Libechov minipig (MeLiM). This original swine model of hereditary metastatic melanoma enables studying biological processes underlying melanoma progression, as well as spontaneous regression. Current histological, immunohistochemical, biochemical, genetic, hematological, immunological, and skin microbiome findings in the MeLiM model are summarized, together with development of new therapeutic approaches based on tumor devitalization. The ongoing study of molecular and immunological base of spontaneous regression in MeLiM model has potential to bring new knowledge of clinical importance.