More common in children • Composite hemangioendothelioma (HE) Composed of at least 2 distinct HE types • Kaposi sarcoma • Angiosarcoma Retiform Hemangioendothelioma at Low MagnificationLow-magnification examination of a retiform hemangioendothelioma (RHE) shows…
SCR presents as single papular or nodular cutaneous lesion GCR is characterized by eruption of multiple small cutaneous lesions • Juvenile xanthogranuloma Typically single lesion occurring in children but can be…
Evidence of apocrine glandular differentiation • Aggressive digital papillary adenocarcinoma Larger nodular tumor with ductal structures More cellular and shows infiltrative features • Metastatic adenocarcinoma Cytologic atypia and mitoses usually prominent Diagnostic…
Clinical history differs – Generally affects unilateral nipple/areola in older adults Clear to pale cells with abundant cytoplasm scattered at all levels in epidermis Nuclear atypia present – Hyperchromatic nuclei – Prominent eosinophilic…
Superficial telangiectatic vessels often present May be associated with mild chronic inflammation • Increased fibroblasts, lymphocytes, and mast cells usually present Top Differential Diagnoses • Hypertrophic scar Lacks characteristic hyalinized collagen bundles…
Parameatal cyst, paraurethral cyst, genitoperineal cyst, mucoid cyst • Midline developmental cyst found at any point from external urethral meatus to anus Etiology/Pathogenesis • Defective embryological closure of median raphe Abnormal closure…
Clinically presents as large, erythematous patch (median: 7 cm) Endothelial multilayering and nuclear atypia Mitotic figures often present Evidence of MYC amplification by FISH or immunohistochemistry • Hobnail hemangioma • Lymphangioma circumscriptum…
Other types of HPV (18, 31, 32, 33, 34, 35, 39, 42, 48, 51, 52, 53, and 54) have also been implicated Clinical Issues • Often multifocal • Benign-looking papules and macules…
Inherited mutations in EVER1/TMC6 or EVER2/TMC8 lead to susceptibility to HPV infection Increased risk for development of in situ and invasive SCC Clinical Issues • As most cases are benign, aggressive…
Subcutaneous or dermal mass • Excellent prognosis, no malignant potential • Complete excision is curative but not necessary given benign nature of lesions Microscopic • Well-circumscribed vascular proliferation • Vessels are thin-walled and closely…
