Limited Wegener granulomatosis of the orbit complicated by Streptococcus anginosis (milleri group) infection

Relapse of Wegener granulomatosis (WG) can be associated with occult inflammation and nasal carriage of Staphylococcus aureus. We report a 79-year-old woman who had a recurrent sclerosing orbital pseudotumor, due to limited WG complicated by Streptococcus anginosis abscess. No sinusitis, other localized infection, or systemic disease was identified by physical examination, imaging, or laboratory studies (negative blood cultures and antineutrophil cytoplasmic antibodies). Histologically, the pseudotumor exhibited predominantly storiform-patterned fibrosis, dense plasma cell infiltrates, neutrophils, nuclear dust and angiocentric fibrosis (i.e., chronic localized fibrosing vasculitis), which coexisted with granular degeneration and mummification of collagen, stellate necrosis, and rare granulomas: diagnostic histologic features of limited orbital WG. The abscess arose within the sclerotic tumor, presumptively, a site of minor resistance seeded during an episode of asymptomatic bacteremia. Surgical debulking and antibiotic therapy were followed by resolution of symptomatic orbital disease. In this instance, bacterial infection may have induced or exacerbated WG.