DIAGNOSIS: Becker melanosis
Becker melanosis (also called Becker’s nevus or Becker’s pigmentary hamartoma) is an organoid hamartoma that is most common among males.1 This benign area of hyperpigmentation typically manifests as a circumscribed patch with an irregular border on the upper trunk, shoulders, or upper arms of young men. Becker melanosis is usually acquired and typically comes to medical attention around the time of puberty, although there may be a history of discoloration (as was true in this case).
A diagnosis that’s usually made clinically
Androgenic origin. Because of the male predominance and association with hypertrichosis (and for that matter, acne), androgens have been thought to play a role in the development of Becker melanosis.2 The condition affects about 1 in 200 young men.1 To date, no specific gene defect has been identified.
Underlying hypoplasia of the breast or musculoskeletal abnormalities are uncommonly associated with Becker melanosis. When these abnormalities are present, the condition is known as Becker’s nevus syndrome.3
Look for the pattern. Becker melanosis is associated with homogenous brown patches with perifollicular hypopigmentation, sometimes with a faint reticular pattern.4,5 The diagnosis can usually be made clinically, but a skin biopsy can be helpful to confirm questionable cases. Dermoscopy can also assist in diagnosis. In this case, our patient’s presentation was typical, and additional studies were not needed.
Other causes of hyperpigmentation
The differential diagnosis includes other localized disorders associated with hyperpigmentation (TABLE1,3,4).
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