Evaluation of the role of routine melan-A immunohistochemistry for exclusion of microinvasion in 120 cases of lentigo maligna

Diagnosis and Management of Lentigo Maligna: Clinical Presentation and Comprehensive Review

Lentigo maligna (LM), also known as Hutchinson's melanotic freckle, is a form of in situ melanoma characterized by the proliferation of atypical melanocytes along the basal epidermis in sun-damaged skin. If left untreated, LM will progress to lentigo maligna melanoma (LMM), a form of invasive melanoma with the same prognosis as other forms of invasive melanoma. LM is more common in the elderly, with a peak occurrence between the ages of 65 and 80 years. LM, however, is rarely present on the trunk and extremities. The diagnosis of LM, confirmed by histopathological and biopsy examination, is based on clinical and dermoscopic features. It typically begins as a tan-brown macule or patch, but it can progress to a variegated pigmentation with dark black color or even amelanotic characteristics. The risk factors involved in the LM development include a history of sunburns, lighter skin types, advanced age, history of nonmelanoma skin cancers, and tendency to form solar lentigines. This article explains the clinical presentation of LM, also reviews the available information on the diagnosis and management of LM, and discusses the potential of such information in facilitating the future prospective.

SOX10 Immunostaining in granulomatous dermatoses and benign reactive lymph nodes

BACKGROUND

SOX10 immunostaining has been considered a highly sensitive and specific marker for melanoma. But there is evidence suggesting that SOX10 positive cells can be present in dermal scars. Therefore, we investigated whether non-melanocytic cell types present in chronic inflammatory processes or benign lymph nodes express SOX10.

METHODS

We retrospectively selected 20 benign lymph nodes and 20 cutaneous granulomatous dermatoses. SOX10, CD68, and Melan-A immunohistochemistry was performed in all cases.

RESULTS

Scattered SOX10 positivity was found in 85% of lymph nodes, specifically in subcapsular and medullary sinuses and in 85% of granulomatous dermatoses. In granulomatous dermatoses, the Melan-A stain did not label the scattered SOX10 positive cells and it was difficult to determine if CD68 was co-expressed on the SOX10 positive cells. In the lymph nodes, the SOX10 positive cells did not co-express Melan-A or CD68.

CONCLUSIONS

We report SOX10 positive cells detected in granulomatous dermatoses and benign lymph nodes. In lymph nodes, SOX10 positive cells were exclusively in subcapsular and medullary sinuses. Therefore, SOX10 is an excellent stain for evaluation of metastatic melanoma with the caveat that positivity in subcapsular and medullary sinuses can be of non-melanocytic origin; the use of additional melanocytic markers is recommended in this situations.

Melanoma: Where we are and where we go

Melanoma is known as an aggressive tumor which shows an increasing incidence and poor prognosis in the metastatic phase. Hence, it seems that diagnosis and effective management (including early diagnosis, choosing of the effective therapeutic platform, caring, and training of patients for early detection) are major aspects of melanoma therapy. Early detection of melanoma is a key point for melanoma therapy. There are various diagnosis options such as assessing of biopsy, imaging techniques, and biomarkers (i.e., several proteins, polymorphism, and liquid biopsy). Among the various biomarkers, assessing circulating tumor cells, cell-free DNAs, cell-free RNAs, and microRNAs (miRNAs) have emerged as powerful diagnosis tools for melanoma patients. Deregulations of these molecules are associated with melanoma pathogenesis. After detection of melanoma, choosing of effective therapeutic regimen is a key step for recovery of melanoma patients. Several studies indicated that various therapeutic approaches including surgery, immunotherapy, systematic therapy, radiation therapy and antibodies therapy could be used as potential therapeutic candidates for melanoma therapy. Caring for melanoma patients is one of the important components of melanoma therapy. Caring and training for melanoma patients could contribute to better monitoring of patients in response to various therapeutic options. Here, we summarized various diagnosis approaches such as assessing biopsy, imaging techniques, and utilization of various biomarkers (i.e., proteins, CTCs, cfDNAs, and miRNAs) as a diagnostic biomarker for detection and monitoring patients with melanoma. Moreover, we highlighted various therapeutic options and caring aspects in patients with melanoma.

Melan-A positive dermal cells in malignant melanoma in situ

The presence of Melan-A positive dermal cells in excisions for melanoma in situ represents a frequent conundrum for pathologists. These cells may represent superficially invasive melanoma, benign, incidental, dermal nevi or non-specific staining of dermal melanophages. Occasionally, rare, Melan-A positive dermal cells are present which do not clearly correspond to the above three categories. Our objective was to further characterize these Melan-A positive dermal cells. To do this, immunoperoxidase staining for Melan-A and SOX-10 was performed on 188-cutaneous excisions, including examples of melanoma in situ, atypical junctional melanocytic hyperplasia and non-melanocytic tumors. These were evaluated for the presence of Melan-A and SOX-10 positive dermal cells. Dermal cells, positive for both markers, were identified in 17% of the excisions. The cells were present in 10% of cases from the melanocytic group and 31% of the cases from the non-melanocytic group. These cells did not exhibit cytologic atypia and resembled neither the co-existing neoplasm nor melanophages. We conclude that positivity of these rare Melan-A positive cells for SOX-10 argues that they represent true melanocytes and not non-specific staining. The absence of cytologic atypia in these cells and their presence in excisions of non-melanocytic neoplasms argues that they are benign, reactive, dermal melanocytes.

Lentigo maligna and lentigo maligna melanoma: contemporary issues in diagnosis and management

Lentigo maligna and lentigo maligna melanomas present diagnostic and treatment dilemmas due to their frequent presence within a background of sun-damaged skin, and their location on cosmetically and functionally sensitive areas. As the incidence of this entity is increasing, diagnostic and management controversies have developed. While surgery remains the gold standard of treatment, nonsurgical treatment options are also emerging for both adjunctive and primary therapy.