Laboratory Studies
Skin biopsy and potassium hydroxide (KOH) examination should be performed, as should a CBC count and liver function profile.
Other tests are guided by findings from a complete history and physical examination [13] and may include the following:
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Serum tumor markers (ie, prostate-specific antigen, carcinoembryonic antigen)
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Serum and urine protein electrophoresis
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Creatinine, BUN, and electrolyte values
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Urinalysis
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Erythrocyte sedimentation rate (ESR)
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Stool guaiac
Imaging Studies
Chest radiography should be performed in all patients suspected of having acrokeratosis paraneoplastica. [13] Other radiological examinations to be considered based on the history and physical examination findings include the following:
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CT scanning of the head/neck, chest, and abdomen
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MRI of the head/neck, chest, and abdomen
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Abdominal or pelvic ultrasonography
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Mammography
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Positron emission tomography scanning
Other Tests
Other tests should be guided by the history, physical examination, imaging, and laboratory findings. These may include the following [13] :
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Upper GI endoscopy
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Bronchoscopy
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Lymph node biopsy
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Bone marrow biopsy
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Cystoscopy
Histologic Findings
Skin biopsy specimens in acrokeratosis paraneoplastica often reveal nonspecific findings. In one review of 80 acrokeratosis paraneoplastica skin biopsy specimens, the most common histologic findings were hyperkeratosis, acanthosis, parakeratosis, and a perivascular infiltrate of lymphocytes and histiocytes. Dyskeratotic keratinocytes, vacuolar degeneration, and pigment incontinence were also occasionally seen. Other reported findings in acrokeratosis paraneoplastica lesions include spongiosis, exocytosis, lichenoid inflammation, and telangiectasias. [12, 22] Note the images below.
At this power, a patchy lichenoid infiltrate of predominantly lymphocytes can be seen underneath an epidermis with psoriasiform hyperplasia and serum crust in the parakeratotic cornified layer (hematoxylin and eosin, 100X).
Focal vacuolar interface change is seen with associated pigment incontinence and exocytosis of lymphocytes (hematoxylin and eosin, 200X).
In acrokeratosis paraneoplastica cases in which immunofluorescence is performed, localized deposits of immunoglobulins, C3, or fibrin may be seen within the basement membrane. [23]
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Acrokeratosis paraneoplastica. A 67-year-old woman presented with scaly plaques of the hands, feet, ears, and nose associated with esophageal squamous cell carcinoma. The eruption resolved with resection of the cancer. Image courtesy of Ronald Grimwood, MD.
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Acrokeratosis paraneoplastica. A 67-year-old woman presented with scaly plaques of the hands, feet, ears, and nose associated with esophageal squamous cell carcinoma. The eruption resolved with resection of the cancer. Image courtesy of Ronald Grimwood, MD.
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Bazex syndrome. Acquired palmar keratoderma in a woman with a history of breast cancer and recent primary lung cancer. Courtesy of Jeffrey J. Meffert, MD.
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Bazex syndrome. Violaceous psoriasiform dermatitis on the ankles. Lung cancer appeared to be in remission; both keratoderma and psoriasiform plaques resolved quickly with clobetasol ointment. Courtesy of Jeffrey J. Meffert, MD.
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At this power, a patchy lichenoid infiltrate of predominantly lymphocytes can be seen underneath an epidermis with psoriasiform hyperplasia and serum crust in the parakeratotic cornified layer (hematoxylin and eosin, 100X).
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Focal vacuolar interface change is seen with associated pigment incontinence and exocytosis of lymphocytes (hematoxylin and eosin, 200X).
