Paraneoplastic Palmoplantar Keratoderma Secondary to Metastatic Uterine Adenocarcinoma

Paraneoplastic palmoplantar keratoderma (PPK) is an acquired dermatosis that presents with hyperkeratosis of the palms and soles in association with visceral malignancies, such as esophageal, gastric, pulmonary, and bladder carcinomas. This condition may either be acquired or inherited.¹

Case Report

A 72-year-old woman was referred to our dermatology clinic for evaluation of a nonpruritic hyperkeratotic eruption predominantly on the palms and soles of 2 to 3 months’ duration (Figure 1A). Review of systems was remarkable for chronic anxiety, unintentional weight loss of 10 lb over the last 6 months, and a mild cough of 10 days’ duration. The differential diagnosis included eczematous dermatitis, tinea manuum, new-onset palmoplantar psoriasis, and PPK.

Figure 1. Palmoplantar keratoderma secondary to uterine adenocarcinoma with thickening of the palms prior to chemotherapy (A). The palmar thickening decreased after completion of treatment (B).

Figure 2. Light microscopy of a punch biopsy specimen from the hypothenar eminence of the left hand showed marked hyperkeratosis (H&E, original magnification ×20).

A punch biopsy of the medial hypothenar eminence of the left hand was performed, revealing notable lichenified hyperkeratosis with vascular ectasia (Figure 2). Periodic acid–Schiff staining was negative for fungal elements. Given the suspicion of PPK, multiple carcinoma markers were ordered. Cancer antigen 125 measured at 68 U/mL (reference range upper limit, 21 U/mL). Cancer antigen 27-29 was 50 U/mL (reference range, <38 U/mL) and cancer antigen 19-9 was 24 U/mL (reference range, <37 U/mL). Computed tomography of the chest revealed a large mass in the left lower lung associated with hilar lymphadenopathy. The patient was referred to oncology for further evaluation. Computed tomography–guided biopsy revealed metastatic uterine adenocarcinoma, which prompted subsequent chemotherapy. The combination of visceral malignancy with PPK led to the diagnosis of acquired PPK secondary to uterine cancer. After the completion of chemotherapy, the palmar dermatosis notably decreased (Figure 1B).

Comment

Paraneoplastic PPK is not uncommon. Ninety percent of acquired diffuse PPK is secondary to cancer,² which occurs more frequently in male patients. Associated visceral malignancies include localized esophageal,³ myeloma,⁴ pulmonary, urinary/bladder,⁵ and gastric carcinoma.⁶ Paraneoplastic PPK in women is rare but has been linked to ovarian and breast carcinoma.⁷

The findings under light microscopy include thickening of any or all of the cell layers of the epidermis, which can include hyperkeratosis, acanthosis, and papillomatosis (Figure 2). A moderate amount of mononuclear cell infiltrates also can be visualized.

Palmoplantar keratoderma associated with uterine malignancy is rare. However, many other paraneoplastic dermatoses resulting from uterine cancer have been described as well as nonuterine gynecological malignancies (Table).^8-17

The first step in managing acquired PPK is to determine its etiology via a complete history and a total-body skin examination. If findings are consistent with a hereditary PPK, then genetic workup is advised. Other suspected etiologies should be investigated via imaging and laboratory analysis.¹⁸

The first approach in managing acquired PPK is to treat the underlying cause. In prior cases, complete resolution of skin findings resulted once the malignancy or associated dermatosis had been treated.^8-17 Adjunctive medication includes topical keratolytics (eg, urea, salicylic acid, lactic acid), topical retinoids, topical psoralen plus UVA, and topical corticosteroids.¹⁸ Vitamin A analogues have been found to be an effective treatment of many hyperkeratotic dermatoses.¹⁹ Isotretinoin and etretinate have been used to treat the cutaneous findings and prevent the onset and progression of esophageal malignancy of the inherited forms of PPK. The oral retinoid acitretin has been shown to rapidly resolve lesions, have persistent effects after 5 months of cessation, and have minimal side effects. Thus, it has been suggested as the first-line treatment of chronic PPK.¹⁹ One study found no response to topical keratolytics (urea cream and salicylic acid ointment) and a 2-week course of oral prednisone; however, low-dose oral acitretin 10 mg once daily resulted in notable improvement over several weeks.⁷ Physical debridement also may be necessary.¹⁸

Conclusion

Palmoplantar keratoderma is a condition that presents with hyperkeratosis of the palms and soles. Acquired PPK often occurs as a paraneoplastic response as well as a stigma of other dermatoses. It occurs more frequently in male patients. Reports of PPK secondary to uterine cancer are not common in the literature. Management of PPK includes a complete history and total-body skin examination. After appropriate imaging and laboratory analysis, treatment of the underlying cause is the best approach. Adjunctive medications include topical keratolytics, topical retinoids, topical psoralen plus UVA, and topical corticosteroids. Oral isotretinoin and etretinate have demonstrated promising results.