Benign tumors including reactive vascular proliferations and ectasias Intravascular Papillary Endothelial Hyperplasia (Masson tumor) Definition A nonneoplastic, reactive, endothelial proliferation representing an organizing thrombus, characterized by formation of arborizing and interconnecting intravascular papillary cores lined by endothelial cells Clinical features…
Benign tumors Rhabdomyomatous Mesenchymal Hamartoma Definition A rare dermal or subcutaneous benign lesion composed of disordered mature elements, including skeletal muscle, adipose tissue, nerve bundles, blood vessels, adnexal tissue, and collagen Initially reported as striated muscle hamartoma Additional terms used…
Benign tumors Glomus Tumor Definition A benign tumor composed of modified smooth muscle cells (e.g., glomus cells) Subclassified into three groups based on the proportions of glomus cells, blood vessels, and (perivascular) smooth muscle cells into: Classical or solid glomus…
Benign tumors and hamartomas Smooth Muscle Hamartoma Definition A hamartomatous lesion composed of a dermal proliferation of mature smooth muscle cells growing in haphazardly arranged bundles Clinical features Epidemiology Slight male predominance Prevalence of 1 in about 2700 live births…
Benign tumors Fibrous Papule Definition A benign proliferation in the superficial dermis, composed of fibroblasts, blood vessels, and sparse inflammatory cell infiltrate in the background of a sclerotic dermal collagen Multiple lesions can be associated with tuberous sclerosis and, less…
Benign fibroblastic and myofibroblastic tumors Hypertrophic Scar Definition A reactive proliferation of fibroblasts/myofibroblasts confined to the boundaries of the wound forming short fascicles, whorls, or nodules, typically lacking keloidal collagen Generally associated with previous local trauma or burns Clinical features…
Benign tumors and reactive conditions Lipoma Definition A benign dermal or subcutaneous mesenchymal tumor composed of mature adult-type adipose tissue Clinical features Epidemiology The most commonly encountered mesenchymal tumor Majority of patients are adults No sex predilection Presentation Most cases…