Abstract
Acrokeratosis paraneoplastica (Bazex syndrome) is a paraneoplastic syndrome frequently associated with squamous cell carcinoma of the aerodigestive tract. We present a case of acrokeratosis paraneoplastica associated with non-small-cell lung carcinoma, which completely resolved once the carcinoma was resected.
Introduction
Acrokeratosis paraneoplastica is a psoriasiform dermatitis often resistant to standard treatment and presents on the acral surfaces. The condition is paraneoplastic heralding an internal malignancy, and as it often presents prior to the diagnosis of a malignancy, it can be an important diagnostic clue.
Case report
A 72-year-old female smoker presented with a 4 month history of painful palmoplantar psoriasiform plaques, unintentional 35 lbs weight loss, chronic productive cough and dyspnea. The plaques were resistant to topical corticosteroids and acitretin.
Physical examination revealed hyperkeratotic and fissured erythematous plaques on bilateral palmoplantar surfaces and lateral digits. The fingernails and toenails were thickened with longitudinal ridging and a yellow discoloration consistent with onychauxis and onychorrhexis (Figure 1). Mild erythema and scaling were noted on the knees, but the ears and nose were spared.

At initial diagnosis, the palmoplantar surface revealed hyperkeratosis and fissured erythema. Nail findings noted were thickening, longitudinal ridging and yellow discolouration.
Suspecting acrokeratosis paraneoplastica, the patient was investigated for an underlying malignancy. Acitretin was stopped, and methotrexate was initiated. However, her symptoms did not improve, and given abnormal pulmonary function tests suggestive of interstitial lung disease, methotrexate was discontinued.
A CT lung displayed a 3 cm right upper lobe nodule with multiple satellite nodules. A biopsy of the lung nodule confirmed a diagnosis of non-small-cell lung carcinoma (NSCLC). Resection of the right upper lung lobe was successful, and the patient declined adjuvant chemotherapy. She noted a gradual improvement of her skin within a month post-surgery, despite a lack of therapy. On follow-up, there was minimal residual erythema and significant normalization of the nails (Figure 2).

After the resection of the carcinoma and despite no topical or oral treatment directed towards the cutaneous condition, the palmoplantar surfaces normalized. Also, noted is significant normalization of the nails with some remaining yellow discoloration.
Discussion
Acrokeratosis paraneoplastica is most often associated with oropharynx squamous cell carcinoma, while 11% of cases are associated with lung carcinomas. 1 It often involves acral sites and nail findings can include dystrophy, hyperkeratosis, yellow pigmentation and onychomadesis. 1 Skin findings often precede the diagnosis of a malignancy by approximately 1 year. 2 In 20% of cases, the skin findings and malignancy are diagnosed simultaneously. 2 Often these patients do not respond to typical therapy for dermatitis.1 The majority of cases resolve with appropriate treatment of the underlying malignancy, and recurrence of cutaneous lesions may herald recurrent systemic disease.
Footnotes
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship and/or publication of this article.
Informed consent
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