Acquired hypertrichosis lanuginosa
HLA is classically associated with lung, breast, and colorectal carcinomas, but has been described in association with a variety of solid tumors. HLA due to internal malignancy shows a strong female predominance and typically occurs between the ages of 40-70 years. HLA may be accompanied by additional paraneoplastic signs or manifestations of internal disease, such as glossitis, taste disturbances, lymphadenopathy, acanthosis nigricans, and the sudden appearance of multiple seborrheic keratoses (ie, sign of Leser-Trélat).
Hair growth can occur up to 2.5 years before the malignancy is identified or up to 5 years after the cancer diagnosis. The etiology of tumor-associated HLA is presumed to be the result of a tumor-secreted product, though specific biochemical or hormonal causes have not been identified to date.
L68.1 – Acquired hypertrichosis lanuginosa
25967007 – Hypertrichosis lanuginosa
Differential Diagnosis & Pitfalls
- Hirsutism – This type of excessive hair growth occurs in females and is distributed in a male pattern. Unlike HLA, the excessive hairs in hirsutism are thicker, terminal hairs. Patients with hirsutism may also have physical findings suggestive of virilization.
- Hypertrichosis lanuginosa congenita – Excessive lanugo hairs are present at birth or shortly thereafter and do not resolve with increased age.
- Acquired hypertrichosis – This type of hair growth is characterized by the development of thick, coarse terminal hairs secondary to medications (eg, cyclosporine, streptomycin, penicillin, phenytoin, spironolactone, diazoxide, minoxidil, interferon, and corticosteroids) or metabolic / endocrine disorders (eg, thyroid dysfunction, anorexia nervosa, HIV/AIDS, and Cushing syndrome).
- Becker nevus – A localized smooth muscle hamartoma that typically presents as a large hyperpigmented patch with increased thick, terminal hairs on the upper extremities or trunk.