INTRODUCTION: Necrotizing sarcoid granulomatosis (NSG) was described by Liebow in 1973 and is the presenting variant of less than 4% of pulmonary sarcoidosis. It is a type of pulmonary angiitis and differs from sarcoidosis by the presence of fibrinoid necrosis. NSG is characterized by nodular pulmonary opacities, usually without hilar lymphadenopathy. On pathology, NSG classically manifests as granulomatous inflammation, fibrinoid necrosis and granulomatous vasculitis. It is considered the pathological equivalent of nodular sarcoidosis. Clinically, NSG is typically with a normal ACE level, benign clinical course and good response to steroids. We present a case of NSG with significant bony involvement, which is rare with this entity.
CASE PRESENTATION: A 28 year-old Caucasian woman presented with 3 month history of right cervical lymphadenopathy, eczematous rash, back pain, and decreased exercise tolerance. Her physical exam was remarkable for right anterior cervical and supraclavicular lymphadenopathy. She appeared well-nourished, was afebrile and had an unremarkable chest exam. She had no localized back tenderness, focal neurological deficits or rash. CT chest revealed bilateral nodular opacities and mediastinal lymphadenopathy with unremarkable thoracic spine. An excisional supraclavicular lymph node biopsy revealed necrotizing granulomatous inflammation with negative bacterial, fungal and AFB cultures. Flow cytometry was negative for clonality; in addition, she had a negative G-INF, negative ANCA and normal ACE level. Cervical lymphadenopathy persisted despite a treatment course of antibiotics. She was given a month trial of steroids, which resulted in resolution of her cervical lymphadenopathy, but no improvement in her back pain. Repeat CT chest 2 months later revealed newly developing discitis and bone destruction in the thoracic spine at T2-T3 level. A thoracic spine MRI confirmed the CT findings along with paravertebral soft tissue swelling, involvement at other vertebral body levels as well as epidural involvement with cord compression. A CT guided FNA of T3 showed chronic inflammation and no evidence of malignancy or infectious organisms. The patient underwent T2 and T3 corpectomy and spine stabilization through anterior approach as well as open lung biopsy. Lung and bone biopsies redemonestrated the finding of necrotizing granulomatous inflammation. IgH molecular analysis, in situ hybridization for EBV, and cultures for bacteria, fungi, and AFB were negative.
DISCUSSION: Bone involvement in sarcoidosis occurs in 5% of the patients. Less than 30 cases of vertebral sarcoidosis have been described and generally involve the lower thoracic and upper lumbar spine. Radiographically, it manifests as osteolytic lesions with preserved disc spaces or widespread sclerosis. Discitis is quite unusual in vertebral sarcoidosis which has a predilection for middle aged African American females. We present a case that is unique in that it affected a young Caucasian female and involved the intervertebral discs. Extrapulmonary involvement in NSG is quite rare. Necrotizing sarcoidosis of the spine is even scarcer with no prior case reports of its occurrence.
CONCLUSIONS: Sarcoidosis is a multisystem granulomatous inflammatory disorder of undetermined etiology and myriad of manifestations. No pathognomonic test exists for sarcoidosis; hence it remains a diagnosis of exclusion. Our case highlights the importance of diagnostic vigilance regarding this disorder. Additionally, it emphasizes the fact that sarcoidosis manifests rather uncommonly as necrotizing granulomatous inflammation that mimics a multitude of infectious, vasculitic and malignant conditions.
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Reference #2 Necrotizing sarcoid granulomatosis: clinical, functional, endoscopical and radiographical evaluations. Eur Respir J; 2005: 26; 778-785.
Reference #3 Liebow AA. The J. Burns Amberson lecture: Pulmonary Angiitis and granulomatosis. Am Rev Respir Dis 1973; 108:1 -17
DISCLOSURE: The following authors have nothing to disclose: Mona Selej, Gabriel Bosslet
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