mart-1-antigen and Carcinoma--Squamous-Cell

Positive staining for SOX10 and the S100 protein are often used in the evaluation of challenging melanocytic neoplasms including melanoma in patient samples. SOX-10 positivity of non-melanocytes in re-excision specimen could complicate the evaluation of invasive melanoma with an invasive desmoplastic component. Therefore, quantifiable data regarding the positivity of SOX-10 in scars will help dermatopathologists to better identify false positive staining.. A retrospective analysis was performed on 50 re-excision specimens from 2013 to 2017, with a diagnosis of squamous cell carcinoma (SCC) or squamous cell carcinoma in situ (SCCIS). Blocks of re-excision specimens containing scars were stained for SOX-10; results were evaluated by a board-certified dermatopathologist. The sum of the five highest numbers of high-power field (HPF) counts as a proxy for "SOX-10 stain factor," and cell morphological features were analyzed. MART-1 and CD68 immunohistochemical staining was performed to study possible lineage of these SOX-10 positive cells.. All 50 specimens showed varying degrees of SOX-10 positivity for histiocytes. SOX-10 positive histiocytes were present in 86% of re-excision scar tissues, of which 71.3% had spindle-shaped or angulated nuclei, and 61.8% had nuclear sizes larger than typical lymphocytes (7 μm). Within the same area of scars, CD68 staining was floridly positive, where as MART-1 staining was overwhelmingly negative.. This study illustrates a potential diagnostic pitfall of using SOX-10 to evaluate re-excision specimens of melanocytic neoplasms and also suggests a previously undescribed staining pattern in scars of SOX-10 positive cells that are not melanocytes. We postulate that such SOX-10 positive cells may represent a small fraction of histiocytes routinely found in scar tissue.

Topics: Adult; Aged; Aged, 80 and over; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Carcinoma, Squamous Cell; Cicatrix; Dermis; Female; Histiocytes; Humans; Immunohistochemistry; Male; MART-1 Antigen; Middle Aged; Retrospective Studies; Skin Neoplasms; SOXE Transcription Factors; Staining and Labeling

Actinic keratosis (AK) and squamous cell carcinoma in-situ (SCCIS) within or near melanoma in situ (MIS) can complicate diagnosis due to overlapping clinical and microscopic features. This study aimed to describe basilar melanocyte density and pagetoid spread in AK and SCCIS for improved diagnostic accuracy.. A total of 22 AK and 22 SCCIS biopsies containing a margin of uninvolved epidermis were immunostained with MART-1 (melanoma antigen recognized by T-cells 1). The basilar melanocyte:keratinocyte ratio and the number and distribution of pagetoid melanocytes were compared in AK, SCCIS, and uninvolved epidermis. An in-vitro human skin model was created to assess the impact of keratinocyte atypia on melanocyte distribution.. The median basilar melanocyte:keratinocyte ratio in SCCIS (1:11.49) was lower than in uninvolved epidermis (1:5.59, P = 0.0011), and the ratio in AK (1:6.94) was similar to uninvolved epidermis (P = 0.987). Pagetoid melanocytes were absent in perilesional skin but common in AK (21/22, P < 0.0001) and SCCIS (22/22, P < 0.0001). Pagetoid melanocytes at or above the mid-spinous layer were more common in SCCIS (21/22) vs AK (7/22, P < 0.0001). Pagetoid melanocytes were present in the in-vitro skin model made with neoplastic but not normal keratinocytes.. Pagetoid melanocytes in AK and SCCIS should be interpreted with caution to avoid overdiagnosis of MIS.

Topics: Adult; Aged; Biomarkers, Tumor; Carcinoma in Situ; Carcinoma, Squamous Cell; Diagnostic Errors; Female; Humans; Keratinocytes; Keratosis, Actinic; Male; MART-1 Antigen; Melanocytes; Melanoma; Middle Aged; Skin Neoplasms

A combined squamomelanocytic tumor is an exceedingly rare occurrence; little is known about its pathogenesis. A definitive diagnosis can only be made via histological examination. We describe herein an 83 year-old man who was discovered to have this combined tumor and recommend the appropriate management for such a lesion.

Topics: Aged, 80 and over; Biomarkers, Tumor; Carcinoma, Squamous Cell; Facial Neoplasms; gp100 Melanoma Antigen; Humans; Keratins; Male; MART-1 Antigen; Melanins; Melanoma; Melanoma-Specific Antigens; Neoplasms, Multiple Primary; S100 Proteins; Skin Neoplasms

Topics: Adult; Aged; Carcinoma, Squamous Cell; Epithelial Cells; Female; Follow-Up Studies; gp100 Melanoma Antigen; Humans; Keratins; Lymphatic Metastasis; Male; MART-1 Antigen; Melanins; Melanocytes; Melanoma-Specific Antigens; Middle Aged; Mouth Floor; Mouth Mucosa; Mouth Neoplasms; S100 Proteins; Tongue Neoplasms

The use of melanoma-associated antigen recognized by T cells (MART-1) immunostain has been proposed as a useful adjunct to overcome the inherent difficulties in the use of frozen sections during Mohs surgery for the treatment of melanoma, but no studies have compared MART-1 frozen sections with MART-1 permanent sections. Current MART-1 1-hour protocols add significant time to the procedure.. To determine whether there is a significant difference between frozen and permanent MART-1 immunostained sections using a rapid 19-minute protocol.. Frozen and permanent sections stained with MART-1 were made from dog-ears excised during 25 reconstructions. A rapid 19-minute protocol was used to stain the frozen tissue. The sections were examined blinded, and statistical analysis was performed to analyze the data.. No significant difference was found in number of keratinocytes, nuclear diameter of keratinocytes, number of melanocytes, melanocytic nuclear diameter, confluence, pagetoid spread, melanocytic nesting, or atypical melanocytes.. The 19-minute protocol is a rapid and effective MART-1 immunostain. Frozen sections stained with MART-1 provide information equivalent to that obtained from MART-1 stained permanent sections. Mohs surgeons using MART-1 can feel confident that they have the same information as they would have obtained using permanent sections using the slow Mohs method.

Topics: Adult; Aged; Aged, 80 and over; Animals; Antigens, Neoplasm; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Dogs; Female; Frozen Sections; Humans; Hutchinson's Melanotic Freckle; Immunohistochemistry; Keratinocytes; Male; MART-1 Antigen; Melanocytes; Melanoma; Middle Aged; Mohs Surgery; Neoplasm Proteins; Skin; Skin Neoplasms

Atypical fibroxanthoma (AFX) is a cutaneous tumor that primarily occurs in the sun-damaged skin of the head and neck of adults. It is often a rapidly growing, solitary lesion that may clinically resemble squamous cell carcinoma, malignant melanoma, or lobular hemangioma. The histologic differential diagnosis primarily includes spindle cell squamous carcinoma and spindle cell melanoma, and immunohistochemical studies are often needed to establish the diagnosis.. We report an unusual case of an AFX with aberrant HMB-45 and MART-1 (melanoma antigen recognized by T cells-1) immunohistochemical expression. Clinical information was obtained. Histologic examination and immunohistochemical studies were performed.. A 54-year-old woman presented with a 1.5 cm posterior scalp lesion, which was excised. Microscopic examination revealed a dermal tumor composed of pleomorphic and spindled cells with numerous giant cells. The tumor cells expressed CD68 but did not express either keratin or S-100. In addition, there was focal gp100 (with HMB-45) and MART-1 expression limited to the large, multinucleated cells with vacuolated cytoplasm. A diagnosis of AFX was subsequently made.. This is the first reported case of an AFX with HMB-45 and MART-1 reactivity.

Topics: Antigens, Neoplasm; Biomarkers, Tumor; Carcinoma, Squamous Cell; Diagnosis, Differential; Female; Giant Cells; Histiocytoma, Benign Fibrous; Humans; MART-1 Antigen; Melanoma; Melanoma-Specific Antigens; Middle Aged; Neoplasm Proteins; Scalp; Skin Neoplasms