Lymphedematous verrucous changes simulating squamous cell carcinoma in long-standing hidradenitis suppurativa

Background Hidradenitis suppurativa (HS) is a relatively common condition marked by abscesses, sinus tracts, and scarring in intertriginous regions of the body. Lymphedema is an under-recognized consequence of chronic inflammation in the setting HS. Methods We report five cases of patients with lymphedema resulting from long-standing HS; the patients were seen either in a specialty HS clinic or general dermatology clinic at our institution. Biopsies for histologic analysis were performed on four of the five patients reported here. Results Changes of lymphedema may be manifested diffusely as widespread plaques or focally as verrucous papules and nodules. The latter may be difficult to distinguish clinically from squamous cell carcinoma, another complication of chronic HS. Histopathologic features of lymphedema include dilated lymphatic channels, diffuse edema, verrucous epidermal hyperplasia, mixed inflammation, and dermal fibrosis. Conclusion Lymphedema associated with chronic HS, which we also term verrucous lymphostasis, encompasses a spectrum of clinical and histopathologic findings. Squamous cell carcinoma may mimic focal presentations of lymphedema, and biopsy may be necessary to distinguish the two.