Background: Patients with skin lesions suspicious for skin cancer or atypical melanocytic nevi of uncertain malignant potential often present to dermatologists, who may have variable dermoscopy triage clinical experience. Objective: To evaluate the clinical utility of a digital dermoscopy image-based artificial intelligence algorithm (DDI-AI device) on the diagnosis and management of skin cancers by dermatologists. Methods: Thirty-six United States board-certified dermatologists evaluated 50 clinical images and 50 digital dermoscopy images of the same skin lesions (25 malignant and 25 benign), first without and then with knowledge of the DDI-AI device output. Participants indicated whether they thought the lesion was likely benign (unremarkable) or malignant (suspicious). Results: The management sensitivity of dermatologists using the DDI-AI device was 91.1%, compared to 84.3% with DDI, and 70.0% with clinical images. The management specificity was 71.0%, compared to 68.4% and 64.9%, respectively. The diagnostic sensitivity of dermatologists using the DDI-AI device was 86.1%, compared to 78.8% with DDI, and 63.4% with clinical images. Diagnostic specificity using the DDI-AI device increased to 80.7%, compared to 75.9% and 73.6%, respectively. Conclusion: The use of the DDI-AI device may quickly, safely, and effectively improve dermoscopy performance, skin cancer diagnosis, and management when used by dermatologists, independent of training and experience.

Spindle cell–predominant trichodiscoma (SCPT) is a benign adnexal neoplasm, best categorized within the trichodiscoma–fibrofolliculoma continuum. SCPTs clinically present as dome-shaped papules usually on the face, particularly on the nose or the nasolabial fold. The SCPT variant has been described as a particularly cellular trichodiscoma composed of small interweaving fascicles and sheets of spindle cells. Identical lesions were previously referred to as neurofollicular hamartomas because of their predominantly fascicular stromal cellularity and focal S100 positivity. In this article, we report a rare variant of SCPT with a palisaded arrangement. The patient is a middle-aged man with no significant dermatologic history who presented with a skin-colored papule on the left nasal ala. It had been present for approximately 10 years with only minimal growth over that time. A biopsy was obtained. Histopathological analysis revealed a dermal papule composed of bland spindle cells arranged in a striking palisading pattern within a fibromyxoid stroma with associated peripheral hyperplasia of sebaceous glands. The palisaded pattern shared features reminiscent of Verocay bodies of a schwannoma. Immunohistochemical studies revealed stromal spindled cells with a strong and diffuse pattern of CD34 expression and absent S100 and SOX10 expressions. To our knowledge, only 2 cases of SCPT with a palisaded pattern have been presented. SCPT with a palisaded pattern is a rare histopathologic variant that may resemble a schwannoma but can be recognized by its strong epithelial components and immunohistochemical staining pattern.

Background and Clinical Significance: Primary Cutaneous Cribriform Apocrine Carcinoma (PCCAC) is a rare, inert low-grade cutaneous malignancy that is diagnosed on histopathologic assessment. PCCAC usually presents in middle-aged adults as a solitary, subcutaneous nodule on the extremities. Characterized by anastomosing tubules and solid/cribriform nests of atypical epithelial cells generating a sieve-like display, the tumor is a histopathological variant of apocrine metaplasia of the skin. PCCAC also follows characteristic staining patterns. It is important to distinguish PCCAC from other similar histological variants, which may hold more grievous indications. Case Presentation: A 47-year-old female presented with an enlarging, itchy growth of several months on her back. On physical exam, an indurated pink, nontender papule of 8 mm on the left lateral side wall was noted. Histopathology demonstrated a well-circumscribed, pandermal tumor composed of anastomosing solid and cribriform nests, tubules, and cords of mildly atypical, eosinophilic epithelial cells forming a glandular lumina. An immunohistochemical study revealed the tumoral epithelium to express CK7, CK5/6, BER-EP4, CD117 (C-kit), and S100. Positive EMA and CEA staining highlighted intratumoral glandular ductal differentiation and apocrine secretion. Immunohistochemical stains for CK20, GATA-3, and p63 were negative. Conclusions: We present this case to distinguish the histological attributes of PCCAC and help differentiate it from more concerning visceral metastatic malignancies. We follow with a narrative review of the histopathologic differential for PCCAC and feature reconciliation of corresponding staining patterns reported in the literature.