Alexander K. C. Leung, MD

February 18, 2011

17-Year-old girl with a 7-month history of small, red papules on her arms and thighs. Rash is not painful or itchy. Otherwise in good health.

September 09, 2010

A 16-year-old boy with asymptomatic, hyperpigmented, hairy lesion on his left upper back. The pigmentation, first noted 5 years earlier, had progressively spread across his torso. The coarse and dark hair confined to the hyperpigmented area had appeared at age 13 years. Medical history uneventful. Review of systems showed no abnormalities. No family history of similar skin lesions.

May 02, 2008

This darkly pigmented lesion on the left arm of a 27-year-old man had been present since birth and had slowly enlarged over the past 2 months. Two days earlier, another physician had diagnosed a wart and treated the lesion with liquid nitrogen, which caused erythema of the surrounding skin.

December 01, 2007

A 50-year-old woman had a 6-month history of severe generalized itchiness and fatigability. There was no associated fever, abdominal pain, or joint pain. A cholecystectomy had been performed 20 years earlier. She had no family history of hypercholesterolemia or liver disease.

September 01, 2007

A 52-year-old man presented with asymptomatic papules on his scrotum. The lesions had first appeared 1 year earlier. He had not sustained local trauma to the scrotum, and his medical history was unremarkable. There was no family history of similar skin lesions.

May 01, 2007

A 45-year-old man sought medical advice after suffering for 6 months with recurrent pain and a purulent discharge at the sacrococcygeal region. Two weeks before this consultation, an abscess on the patient's right buttock had been drained by another physician. The patient had type 1 diabetes mellitus for 5 years; his medical history was otherwise unremarkable.

February 02, 2006

The parents of this 5-month-old boy were concerned that his eyes wereturned in toward the nose. The infant was otherwise healthy. Physical findingswere normal. In particular, when a light source was projected onto theeyes, the light reflex was centered in both eyes.

November 01, 2005

This black lesion had been present on the upper back of a 5-year-old girl since birth. The lesion had gradually enlarged to its current size of 1.5 cm. In the past year, 3 satellite black macules had developed in the surrounding area.

September 14, 2005

This obstruction is caused by a failure of intestinal peristalsis; there is no evidence of mechanical obstruction. Paralytic ileus is common after abdominal surgery, especially if anticholinergic drugs are given preoperatively and/or narcotics are used postoperatively. It usually lasts 2 to 3 days. Paralytic ileus may also be caused by peritonitis; ischemia or surgical manipulation of the bowel; retroperitoneal hemorrhage; spinal fracture; systemic sepsis; shock; hypokalemia; uremia; pharmacologic agents (eg, vincristine, loperamide, and calcium channel blockers); diabetic ketoacidosis; and myxedema.

September 14, 2005

These are hyperpigmented, regularly bordered, sharply demarcated macules that are usually tan or light brown in whites and dark brown in dark-skinned persons. The lesions are characterized by an increased number of melanocytes and an increased amount of melanin in the epidermis.