Lupus erythematosus panniculitis (LEP) has been reported to be the first manifestation of systemic lupus erythematosus (SLE)1. Face and upper limbs are most commonly involved; however, extensive LEP in the buttock region or breasts is relatively rare, but also reported2,3. Differential diagnosis such as subcutaneous panniculitis-like T cell lymphoma should always be considered4.
A 41-year-old woman presented with an area of tender swelling on her right buttock, which subsequently shrank forming an extensive depression after 3 months (Figure 1). Arthritis, malar rash, and oral ulcers were also noted. Serological studies showed positive antinuclear antibodies (1:160, nucleolar pattern) and positive anti-dsDNA (14.3 IU/ml, normal < 10 IU/ml). She was diagnosed with SLE since she fulfilled more than 4 criteria of the 1997-revised criteria for the classification of SLE5. Her serum complement levels were within normal range (C3: 113 mg/dl, normal 90–180 mg/dl and C4: 29.6 mg/dl, normal 10–40 mg/dl). Magnetic resonance imaging revealed a markedly decreased volume of the subcutaneous fatty layer and thickening over the covering cutis with edema along the lateroposterior site of the right gluteus maximus. A skin biopsy disclosed lobular panniculitis with infiltration of lymphoplasmacytic cells, focal hyaline fat necrosis, and fibrin deposition on the vascular walls (Figure 2). Intravenous methylprednisolone (1 mg/kg) was prescribed for 5 days, followed by oral prednisolone (40 mg/day), hydroxychloroquine (200 mg/day), and azathioprine (100 mg/day) for more than 3 months. The extensive induration extending from her buttock to hip region indicated a poor response to treatment.
An extensive lipoatrophy presented on the patient’s right buttock within 3 months.
Skin biopsy disclosed lobular panniculitis with infiltration of lymphoplasmacytic cells.