INTRODUCTION: A 63 year old male presented with an indurated facial lesion, cervical lymphadenopathy and a PET positive lung mass. Multiple biopsies showed a plasma cell and histiocytic infiltrate with no evidence of malignancy. Pathology revealed features of pseudotumor with similar findings on all biopsy specimens. A diagnosis of IgG4 sclerosing disease was considered. The patient was started on corticosteroids with improvement in symptoms and a decrease in size of the multiple foci of disease.
CASE PRESENTATION: A 63 year old male with 60 pack year history of smoking presented to his local dermatologist in March 2010 with two month history of a violaceous indurated facial lesion. Antibiotics had been unsuccessful in resolving the lesion. Serologies for connective tissue diseases were negative. Skin biopsy showed sheets of plasma cells. A palpable submandibular lymph node was also discovered. Otorhinolaryngology was consulted and the lymph node was excised, revealing reactive lymph nodes with a dense pericapsular fibro-inflammatory rind and inflammatory pseudotumorous proliferation. Flow cytometry was negative. CT of the chest in April 2010 showed a 9 mm left upper lobe ground glass opacity, but was otherwise negative. In July 2010, he developed right sided neck pain. Because of continued severe pain, he was evaluated in a local emergency department in October 2010. CT of the neck suggested a left upper lobe mass, and a CT of the chest showed a large mass in the left upper lobe as well as two additional nodules in the right apex. The patient saw a local pulmonologist and a CT guided biopsy was obtained which was negative for malignancy but showed “fibrous tissue.” He was referred to a thoracic surgeon who performed mediastinoscopy which was negative for malignancy, but showed changes suggestive of inflammation, with an abundance of plasma cells. The patient presented to our institution in December 2010 for evaluation. CT of the chest confirmed a large apical left upper lobe mass adjacent to the mediastinum as well as enlarged mediastinal lymph nodes. Erythrocyte sedimentation rate, connective tissue disease serologies, and ANCAs were negative. Thoracic surgery was consulted performed a left thoracotomy with resection of the mass to rule out lymphoma. Pathology of the mass was consistent with inflammatory pseudotumor. IgG4 stains showed significant numbers of plasma cells positive for IgG4 stain, with an IgG4/IgG ratio of 30%. Bone marrow biopsy was negative. The patient was then begun on Prednisone 40 mg daily. Follow up CT of the chest two months from initiation of treatment showed the previously mildly enlarged right level Ib lymph node to be decreased in size and the premaxillary soft tissue mass to have resolved. The residual left upper lobe nodule appeared smaller as did the two smaller nodules in the right upper lobe. The mediastinal lymphadenopathy was stable. The patients neck pain had almost completely resolved.
DISCUSSION: Inflammatory pseudotumor of the lung typically presents as solitary nodules which can be locally invasive. Similar lesions can present in other tissues. The etiology of these lesions is unknown; staining usually reveals the presence of IgG predominant polyclonal plasma cells, as in our patient. Some evidence points to clonal DNA expression of Epstein Barr virus (our patient’s was negative). Differential diagnosis includes other inflammatory conditions such as infection, cryptogenic organizing pneumonia (COP), and lymphomas. Treatment typically includes surgical resection. There are anectdotal reports of both success and failure with glucocorticoids. Some lesions have been noted to regress after biopsy (our patient reported this).
CONCLUSIONS: IgG4 sclerosing disease is typically associated with autoimmune pancreatitis, but can be seen in the absence of this finding. Typically the level of IgG4/IgG plasma cells exceeds 30%, or 10 IgG4 positive cells per high power field. These lesions typically respond to corticosteroids, although residual disease can persist. This case is atypical because of the multifocal disease including biopsy-proven disease in the face, cervical nodes, and chest.
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Reference #2 Zen, Y. IgG4-related lung and pleural disease: a clinicopathologic study of 21 cases. American J Surg Path. 2009 Dec;33(12):1886-93.
Reference #3 Kim, Y. IgG4-related inflammatory pseudotumor of the lung, a pulmonary manifestation of the IgG4-related sclerosing disease. Basic and Applied Pathology, March 2011: Vol 4, Issue 1, pp14 - 17.
DISCLOSURE: The following authors have nothing to disclose: John Moss, Jack Leventhal
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