Alexander K.C. Leung, MD, MBBS, FRCPC, FRCP

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.

Median nail dystrophy presents as a midline or paramedian canal, split, or ridge in the nail plate, beginning at or distal to the proximal nail fold.

A 7-year-old boy presented with an asymptomatic light patch on his back that had been first noted in the neonatal period. The patch had been stable in shape, distribution, texture, and relative size since...

<p>A 17-year-old Canadian girl complains of painful swelling on all her toes, which started 10 days earlier when the weather was very cold. She used to walk around barefoot in a poorly insulated...

A 3-year-old girl discovered lesions on her instep and great toe, where there was significant pressure from the old rubber sandals that she had been wearing.