Plasma cell granuloma, a form of inflammatory pseudotumor, is a rare nonneoplastic lesion that is characterized by cellular proliferation composed predominantly of polyclonal plasma cells with other inflammatory cells in fibrovascular background. We have experienced an unusual case of plasma cell granuloma of skull that developed in a patient with systemic lupus erythematosus (SLE). A 42-year-old female diagnosed with SLE 13 years ago has complained of palpable scalp mass and headache beginning ten days previously. A brain magnetic resonance imaging showed intensely enhanced soft tissue mass with focal bone defect in right parietal bone and whole body positron emission tomography suggested high possibility of malignancy. Surgical tumor removal was performed. Biopsy specimen revealed inflammatory proliferation predominantly with mature plasma cells which were determined to be polyclonal in immunostaining. Currently, 4 months after surgery, the patient are on regular follow-up with oral medications (prednisolone, hydroxychloroquine) for SLE without evidence of recurrence.

Keywords: Plasma cell granuloma, Skull, Systemic lupus erythematosus