Atypical CT Imaging of Thoracic Sarcoid Case Series

Title: Atypical CT Imaging of Thoracic Sarcoid Case Series
Author(s): H Dolphin M Bolger M Rogan M Farrell S Foley
Institution: University Hospital Waterford
Poster: Click to view poster
Category: General Respiratory and Sleep
Abstract: The characteristic imaging features of thoracic sarcoid are well recognised and include bihilar and mediastinal lymphadenopathy, perilymphatic pulmonary micronodules and pulmonary fibrosis predominantly of the upper and mid- zones. However, atypical features occur on CT imaging in up to 30% of cases.

We present a case series of nine patients with atypical CT appearances of thoracic sarcoid from the respiratory chest conference at a tertiary referral centre. Histological confirmation of the diagnosis was made in all cases.

Unilateral hilar adenopathy was an incidental finding in two cases of thoracic sarcoid without respiratory symptoms. Large pulmonary nodules were seen in two patients, one of whom presented asymptomatically. Biopsy of these nodules subsequently confirmed pulmonary sarcoid. Wedge-
shaped opacities were imaged in 2 patients, with a differential for this appearance of COP/BOOP or pneumonia. Three patients had patchy ground glass airspace opacifications and presented variably with dry cough and dyspnoea, imaging mimicked acute alveolitis, hypersensitivity pneumonitis or BAC and had ultimate histological confirmation of sarcoidosis.

The imaging features of bilateral hilar and mediastinal adenopathy with/without pulmonary parenchymal micronodularity are characteristic for the disease and present in approximately 70% of patients. However sarcoidosis is coined “the great mimicker” due to its many ambiguous forms of atypical imaging features as described. Recognition of the atypical CT appearances of the disease is relevant for treating physicians and radiologists.