An Unusual Etiology for an Acral Psoriasiform Dermatosis.

A 53-year-old Caucasian female presented with a 4-month history of painful scaly plaques on the palms and feet. This progressed into inflammation with fissuring, affecting the fingers and toes. The patient was a current smoker with a 40-pack-year history. From her past medical history, she had essential hypertension and glaucoma. She had previously visited a private dermatologist who prescribed topical methylprednisolone ointment once daily for 2 weeks, topical emollients, and soap substitutes with no improvement.

On clinical examination, there was symmetrical psoriasiform hyperkeratosis on both palms and soles; there was also subungual hyperkeratosis and dystrophic nails [Figures 1 and 2]. Laboratory investigations showed erythrocyte sedimentation rate of 32 mm in first hour (normal range 0–30) but were otherwise unremarkable. Due to hoarseness of voice, she was reviewed by the ear, nose, and throat (ENT) team who organized a computed tomography of the neck. This revealed a heterogeneous hypoattenuated lesion in the right lobe of thyroid without calcification [Figure 3]. Thyroid scintigraphy revealed nodules on both lobes and a solitary cold thyroid nodule in the left lobe that was highly suspicious for thyroid malignancy. The patient underwent total thyroidectomy. Following tumor resection, the palmoplantar dermatosis significantly improved.

Figure 1

Marked confluent hyperkeratosis of the palms sparing of the central portion

Figure 2

Hyperkeratosis of the fingers and onycholysis of the fingernails

Figure 3

Axial computed tomography image shows a heterogeneous hypoattenuated lesion in the right lobe of thyroid without calcifications. After contrast administration, the lesion presented mild heterogeneous enhancement

Histological findings

An incisional biopsy taken from the right palm showed parakeratosis, lymphocyte exocytosis with psoriasiform spongiotic dermatitis [Figure 4]. Histology from the thyroid confirmed an underlying diagnosis of multifocal papillary thyroid cancer.

Figure 4

Histopathology shows acanthosis and mildly spongiotic epidermis with minimal interface, eosinophils in the dermis, and overlying parakeratosis (H and E, x40)

What Is Your Diagnosis?

Diagnosis

Bazex syndrome.

Clinical course

We diagnosed her skin condition as a paraneoplastic condition known as Bazex syndrome, based on the new onset of typical skin findings associated with the tumor. This diagnosis was confirmed when the skin lesions resolved after 3 weeks of thyroidectomy. There was no recurrence of skin lesions at 2-month follow-up.

Discussion

Acrokeratosis paraneoplastica Bazex (Bazex syndrome) (APB) is a rare paraneoplastic skin disease defined by erythematous, violaceous, scaly plaques on the hands and feet and on other acral locations such as nose and ears.[1] This syndrome typically presents with hyperkeratosis of acral sites, with characteristic sparing of the central portion.[2] In addition, there are often nail changes such as onycholysis, dystrophy and discoloration. Given the psoriasiform nature of the dermatosis, patients are often mistakenly treated for psoriasis, thus critically delaying the diagnosis of their underlying malignancy.[12]

APB is linked to a variety of underlying malignancies. Usually, the skin lesions develop prior to the diagnosis of an internal malignant neoplasm with spontaneous remission after tumor removal.[1234] It is most frequently associated with squamous cell carcinoma (SCC), such as SCC of the pharynx, esophagus, and larynx, but the diagnosis does not preclude if the tumor origin is located elsewhere.[12] The cause of the skin changes is still to be identified, but theories include cross reactivity of tumor antigens with the skin basement membrane and tumor growth factors inducing hyperkeratosis and possible Zinc or vitamin A deficiency.[2]

The histological features of APB are often nonspecific with no classical histological pattern. Usually, there is hyperkeratosis, parakeratosis, acanthosis, spongiosis, and a perivascular inflammatory infiltrate in the dermis.[1] Improvement of the skin can be achieved by treating the underlying malignant condition; return of the skin lesions can signal tumor recurrence.

Due to clinical appearance resembling psoriasis, the diagnosis often can be missed. Therefore, inflammatory skin conditions with unusual presentation and therapy resistance should hint at paraneoplastic syndrome and require further diagnostic work up.[1]

Learning points

APB is a rare acral psoriasiform dermatosis associated with internal malignancy.

The syndrome of acrokeratosis paraneoplastica typically precedes the diagnosis of malignancy.

Cutaneous manifestations of acrokeratosis paraneoplastica include symmetrical, acral, scaly, red-to-violaceous plaques or patches, and striking nail changes

It may be mistaken for psoriasis, leading to delayed diagnosis.

Treatment of the underlying malignancy will treat the dermatosis, although the nail changes may persist.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.