'When you hear hooves, think zebras, not horses'; two challenging cases of interstitial lung disease (ILD)

Abstract

Our case series describes two siblings with complex fibrosing lung diseases. The first patient was initially given a diagnosis of sarcoidosis based on imaging and exclusion of alternative diagnoses. A number of years after diagnosis, he had rapid deterioration of his disease and following surgical lung biopsy, his lung fibrosis was re-classified as chronic hypersensitivity pneumonitis (cHP) with a usual interstitial pneumonia pattern. He subsequently underwent successful lung transplantation. The second patient presented with rapidly progressing exertional dyspnoea. His bloods, imaging, bronchoalveolar lavage and histology were discussed at our multidisciplinary team meeting. His histology was most in keeping with subacute on cHP with overlapping imaging features between the two siblings. He was treated accordingly but unfortunately succumbed to his illness shortly after diagnosis. These cases highlight the difficulties differentiating between the various interstitial lung disease (ILD) subtypes and the challenges in management while also increasing awareness of familial ILD.

Keywords: cardiothoracic surgery; drugs: respiratory system; interstitial lung disease; medical management; respiratory medicine.

Figure 1

A–D: These images demonstrate the progression of disease over the 4-year period in our first patient. (A) Shows a CT of the chest on first presentation. It demonstrates diffuse bilateral ground-glass opacities with multiple centri-lobular and subpleural nodules. These changes were most prominent in the upper lobes. (B) Shows a chest CT 2 years later showing mild progression of fibrosis changes with persistent pulmonary nodules and ground glass opacification and mild bronchiectasis. (C) Shows chest CT 4 years later (admission described above) showing extensive pulmonary fibrosis with significant traction bronchiectasis and honeycombing. (D) Shows his final CT pulmonary angiogram prior to lung transplantation. This shows low lung volumes, significant bilateral fibrosis, honeycombing and bronchiectasis.

Figure 2

A–D: These images demonstrate histopathology images from surgical lung biopsy performed in our first patient. (A,B) Show lung parenchyma with interstitial fibrosis and spatial and temporal heterogeneity with honeycombing (green arrow) and numerous fibroblastic foci (yellow stars). (C,D) Show numerous loose giant cells granulomas (blue circles) which were observed peri-bronchially (C) and in the interstitium (D) (scale bar A=1000 μm, B–D=100 μm).