Eccrine angiomatous hamartoma
EAH typically presents as a red, violaceous, or brownish nodule or plaque on an extremity. Papules or macules are less frequently seen. The face, neck, and trunk may also be primary sites of involvement. Patients report variable levels of pain. This is thought to occur as a result of small nerves that are seen on electron microscopy in close proximity to the eccrine and vascular structures. Hypertrichosis of the tumor is encountered in most cases. Hyperhidrosis is an additional diagnostic feature that is seen in under half of reported cases.
EAH is classically solitary; however, multiple tumors in a Blaschkoid or segmental distribution have been described. EAH grows proportionately with the affected individual.
Females and males are equally affected.
Q85.8 – Other phakomatoses, not elsewhere classified
239115005 – Eccrine angiomatous hamartoma
Differential Diagnosis & Pitfalls
- Eccrine nevus – Characterized histopathologically by an increase in eccrine structures but not capillaries. Clinical hallmark is hyperhidrosis in most cases.
- Tufted angioma
- Smooth muscle hamartoma – These skin-colored plaques may have associated hypertrichosis. A "chicken-skin" appearance (pseudo-Darier sign) may be seen with piloerection.
- Glomus tumor – Painful bluish papules, single or multiple, are encountered, mainly on acral areas of the body.
- Blue rubber bleb nevus
- Sudoriparous angioma – Another rare, benign tumor where eccrine glands of normal number are seen lying close to vascular structures in the dermis; these have a larger caliber than those seen in EAH.