Atypical acral persistent papular mucinosis

A 70‐year‐old woman presented with a 10‐year history of cutaneous lesions on her calves that worsened with solar exposure. Her past medical history was irrelevant. Physical examination revealed 10–15 erythematous, firm nodules with a diameter of 2–5 mm, which were slightly painful on palpation. The lesions were located on both calves, although some elements extended to the posterior side of the thighs ( Fig. 1). General physical examination did not show any abnormalities. A biopsy specimen from one of the elements showed a normal epidermis and, in the upper dermis, a slight inflammatory infiltrate of mononuclear cells, with the presence of splits between collagen fibers ( Fig. 2). Alcian blue stain at pH 2.5 revealed the existence of mucinous material in these spaces ( Fig. 3). An electron microscopic study did not show any abnormalities. 1 Clinical appearance of the lesions 2 Histopathologic picture (hematoxylin and eosin, ×40) 3 Alcian blue stain showing the presence of mucin in the dermis (Alcian blue, ×100) The patient was diagnosed as having papular mucinosis. The following studies were normal or negative: complete cell blood count, serum biochemistry, serum protein electrophoresis, serum immunoelectrophoresis, serologic test for human immunodeficiency virus (HIV), hepatitis B and C viruses, and syphilis, antinuclear antibodies, and thyroid hormone levels. No treatment was carried out.