Infiltrative basal cell carcinoma mimicking tinea corporis.

The diagnosis of infiltrative basal cell carcinoma (BCC) can be delayed owing to its often subtle clinical findings. A 90-year-old woman presented with an asymptomatic annular pink plaque on her left shin that was clinically diagnosed as tinea corporis. After years of not responding to topical anti-fungal therapy, biopsies confirmed a diagnosis of infiltrative BCC. We discuss the differential diagnosis of the case, the difficulties in identifying infiltrative BCC, and the pathologic features of infiltrative BCC.

Perforating gout of the ear.

Gout is the most common cause of inflammatory arthritis in men over 40 [1]. The prevalence of gout in the US is approximately 3.9%. Tophus is a characteristic sign of gout and results when monosodium urate deposits at the joint, skin, or cartilage. Tophi develop in 12-35% of patients who are diagnosed with gout [2]. We report a case of a 70-year-old man who was diagnosed with squamous cell carcinoma of the helix via shave biopsy. During Mohs micrographic surgery, a vigorous foreign-body reaction was noted. Review of the initial biopsy slides identified crystals with pseudoepitheliomatous hyperplasia (PEH) rendering a diagnosis of gout. This case emphasizes the importance of recognizing causes of PEH and the predilection for tophi to form on the ear.

Diffuse lichenplanopilaris and multiple squamous neoplasms.

Lichen planus is an inflammatory process that can affect the skin, mucosa, and hair follicles. An increased risk of squamous cell carcinoma has been noted in lichen planus of the mucosa. Rarely, in chronic, hypertrophic lichen planus of the skin, squamous cell neoplasms have been reported. We report a case of new onset lichen planopilaris with multiple squamous cell neoplasms.

Treatment of necrobiotic xanthogranuloma with 2-chlorodeoxyadenosine.

A 71-year-old man presented with ulcerating yellow-red plaques of the back, chest, face, and extremities (Figure 1). He had a 10-year history of these lesions. The initial plaque appeared on the back followed by rapid progression of multiple similar lesions involving the face, chest, abdomen, and extremities. The plaques on his face were predominately in the periorbital and eyelid regions. Skin biopsy revealed an ulcerated epidermis. Dense sheets of foamy histiocytes were present in the dermis and contained foci of necrobiosis. Numerous Touton giant cells were present and cholesterol clefts were prominent. Special stains for organisms were negative. On further laboratory evaluation, serum protein electrophoresis revealed a monoclonal spike of 0.5 g/dL IgG lambda. Results from bone marrow biopsy were negative. Other significant laboratory findings included an elevated sedimentation rate and low serum complement. Clinical findings, histopathology, and laboratory evaluations were consistent with the diagnosis of necrobiotic xanthogranuloma (NXG).