Dermatologic Disorders

Mastocytosis is a rare heterogenous group of disorders characterized by a clonal proliferation and accumulation of mast cells in one or more organs, mostly skin and bone marrow and, less frequently,...

The olecranon bursa is a superficial bursa located immediately posterior to the olecranon process of the ulna bone and triceps tendon and loosely connected to the overlying skin in the elbow area.

A popliteal cyst, also known as a Baker cyst or parameniscal cyst, forms when the synovial fluid from the knee joint fills and distends a preexisting gastrocnemius-semimembranosus bursa in the popliteal...

A ganglion cyst is a benign cystic swelling that typically arises from the synovium of either a tendon sheath or a joint capsule.

Dermatosis papulosa nigra is a common, benign epidermal growth characterized by the presence of multiple, asymptomatic, hyperpigmented, round, dome-shaped or flat, papules or macules localized predominately...

Steatocystoma multiplex is a rare skin condition clinically characterized by multiple, asymptomatic, smooth, round, soft to firm, often freely movable, yellow or skin-colored papules and nodules.

This article is part of a series describing and differentiating dermatologic lumps and bumps. In Part 31, Leung and colleagues describe juvenile xanthogranuloma. To access previously published articles in...

This article is part of a series describing and differentiating dermatologic lumps and bumps. In Part 43, Leung and colleagues describe blue nevi. To access previously published articles in the series,...

This article is part of a series describing and differentiating dermatologic lumps and bumps. In Part 28, Leung and colleagues describe dermatofibroma. To access previously published articles in the series,...

This article is part of a series describing and differentiating dermatologic lumps and bumps. In Part 42, Leung and colleagues describe acquired melanocytic nevi. To access previously published articles in...