Acrokeratosis paraneoplastica, also known as Bazex syndrome, is a paraneoplastic skin disorder most commonly associated with squamous cell carcinoma of the upper respiratory tract, gastrointestinal adenocarcinoma, prostate cancer, and less frequently with tumors in other locations. Its ICD-10 code is L85.1.
Acrokeratosis paraneoplastica, which is extremely rare, is most commonly observed in men over the age of 50 with a history of alcohol abuse and tobacco smoking. This condition is classified as an obligate paraneoplastic dermatosis, and in the majority of cases tumors are found in the head and neck region, particularly in the oral cavity, nasopharynx, and upper respiratory tract. Morphologically, the tumors are squamous cell carcinomas. Cases of concurrent cutaneous manifestations with lung and esophageal tumors have been reported. Skin manifestations typically appear at least 10-12 months prior to cancer diagnosis.
It manifests as stagnant erythema and scaling of the skin in acral areas such as the palms, soles, nose, earlobes, and hairy scalp. The eruptions are often psoriatic in nature. As the oncologic process progresses, the affected areas may be found around the knee and elbow joints, and nail dystrophy develops. There may be a combination with other paraneoplastic syndromes and symptoms, such as acquired ichthyosis, Gamel's erythema, poikiloderma, pruritus, and others.
Diagnosis in the early stages can be challenging. Histologic examination reveals non-specific changes including hyperkeratosis, focal parakeratosis and acanthosis. Perivascular lymphocytic infiltrates are seen in the dermis.
- Psoriasis
- Lupus erythematosus
- Photodermatitis
- Fungal infection
- Onychomycosis
- Keratodermas
Treatment is not very effective, although there are reports of positive effects of systemic retinoids (acitretin). The dynamics of skin manifestations usually reflects the dynamics of the oncological process. With successful treatment of cancer, the skin changes regress spontaneously.