A benign vascular tumor presenting as a slow-growing, deep-red to purple plaque with small nodules, often with hyperhidrosis or hypertrichosis.
A pre-malignant lesion on sun-exposed skin that feels like a rough, dry, adherent, sandpaper-like patch.
A melanoma that lacks pigment, presenting as a pink or red, often ulcerated and bleeding nodule that can mimic other lesions.
An aggressive vascular malignancy, often on the scalp of the elderly, that presents as an ill-defined, expanding, bruise-like patch or purpuric nodule.
A low-grade sarcoma on sun-damaged skin of the elderly, typically presenting as a rapidly growing, solitary, reddish, ulcerated nodule.
An infection presenting as a crusted, verrucous, or ulcerative nodule on an extremity, often following aquatic exposure ('fishtank granuloma').
Primary cutaneous B-cell lymphoma can present as solitary or grouped, violaceous or reddish-brown nodules and tumors, typically on the head or trunk.
Presents as a classic pearly, translucent papule or nodule with fine, overlying blood vessels (telangiectasias) and a tendency to centrally ulcerate.
Presents as a hard, white or yellowish, subcutaneous nodule that may extrude chalky material.
A rare, slow-growing, firm, subcutaneous nodule, typically on the head and neck, known as a 'mixed tumor' of the skin.
A benign tumor, typically on the lower legs, appearing as a solitary, well-demarcated, moist, reddish-brown plaque or nodule with a 'stuck-on' look.
Cancer that has spread to the skin, often appearing as a firm, non-tender, rapidly appearing, reddish or skin-colored nodule.
A benign adnexal tumor presenting as a solitary or multiple smooth, pink nodules, commonly on the scalp where multiple lesions can form a 'turban tumor'.
Can present as a chronic, verrucous (wart-like) or ulcerative nodule that fails to heal, such as in blastomycosis or chromoblastomycosis.
A common, firm, button-like dermal nodule that characteristically dimples or retracts downwards when pinched.
A low-grade sarcoma that begins as a firm, plaque-like lesion and slowly grows into a large, protuberant, reddish-blue multinodular mass.
A congenital cyst, often found on the face along embryonic fusion lines (especially near the eyebrows), that is firm, non-mobile, and contains skin structures.
A benign sweat gland tumor, usually on the soles or palms, presenting as a solitary, moist, red, often pedunculated or sessile nodule.
A benign sweat gland tumor that presents as a deep-seated, solitary nodule that is characteristically painful.
A common, firm, dome-shaped subcutaneous nodule with a central punctum, which contains cheesy, foul-smelling keratin debris.
Another name for a dermatofibroma, a common, firm, button-like dermal nodule that characteristically dimples when pinched.
A benign tumor of blood vessels, such as an infantile hemangioma, which appears as a bright red, raised, 'strawberry' mark that grows and then involutes.
A translucent, dome-shaped cyst typically found on the face, especially around the eyes, containing clear or bluish fluid from a sweat gland.
A mature, benign mole that is raised, dome-shaped, flesh-colored or light brown, and soft, with no junctional (flat) component.
A benign histiocytic proliferation in children, presenting as a solitary, firm, yellow-to-red-brown, dome-shaped papule or nodule.
An overgrowth of scar tissue that extends beyond the borders of the original wound, forming a firm, smooth, rubbery nodule.
A rapidly growing tumor with a characteristic volcano-like shape, featuring a smooth, rolled border and a central keratin-filled crater.
A solitary collection of mast cells, appearing as a yellowish-tan or reddish-brown plaque or nodule that urticates (forms a hive) when rubbed (Darier's sign).
A soft, skin-colored, 'button-hole' like papule or nodule that invaginates into the skin with pressure.
A proliferation of nerve tissue that can form a painful, firm, subcutaneous nodule, often at a site of prior trauma or surgery.
A benign hair follicle tumor, usually in a child or young adult, presenting as a very hard, deep-seated, rock-like nodule that may have a bluish hue.
A clonal keratinization disorder presenting as a slowly enlarging annular plaque with a distinct, thread-like, raised keratotic border (cornoid lamella).
A large, lobulated tumor, usually on the scalp of an elderly woman, arising from a pilar cyst, that can ulcerate and grow rapidly.
A benign, rapidly growing vascular proliferation that presents as a bright red, friable, raspberry-like nodule that bleeds very easily.
A firm, non-tender, subcutaneous nodule found over joints and pressure points in patients with rheumatoid arthritis.
A benign nerve sheath tumor that presents as a solitary, slow-growing, encapsulated, often tender subcutaneous nodule.
A benign, waxy, hyperpigmented, 'stuck-on' papule or plaque with a verrucous surface and characteristic horn cysts.
A benign melanocytic nevus, common in children, that often appears as a rapidly growing, symmetric, pink or red, dome-shaped papule or nodule.
A malignant tumor presenting as a firm, indurated, hyperkeratotic, or ulcerated nodule on sun-exposed skin that fails to heal.
A variant of granuloma annulare presenting as deep, firm, non-tender, skin-colored nodules, often on the shins or scalp of children.
A benign hair follicle tumor, appearing as a small, warty, skin-colored papule on the central face, which is a key sign of Cowden syndrome when multiple.
A benign hair follicle tumor appearing as multiple, small, skin-colored or pearly papules on the central face, especially the nasolabial folds.
A common wart (verruca vulgaris) is a hyperkeratotic, papillomatous papule with thrombosed capillaries appearing as black dots, that interrupts normal skin lines.
A solitary nodule with a central, umbilicated, keratin-filled plug, typically on the head or neck of an older individual.
A deposition of lipid, which can form a firm, painless, reddish-yellow nodule (tuberous xanthoma), often over joints.
