A 57-year-old man was hospitalized in our service in 2017 to explore a mMRC grade 2 dyspnoea in the context of interstitial pneumonia on his chest X-ray.
His main medical history was emphysema of upper lobes diagnosed 5 years earlier, his follow-up consisted of a medical consultation with CT scan and pulmonary function test every 6 months (his last spirometry found a FEV1/VC ratio of 73% and a DLCO of 71%); he also presented a ventricular tachycardia which required the installation of a cardiac defibrillator. We did not find any significant family medical history.
This patient was living in a healthy house, but, reported multiple exposures. In his past work as a plumber, he was exposed to asbestos then he worked in a foundry with possible exposition to alloys of copper, bronze, iron, aluminium and zirconium compounds. He also described domestic exposures (hens of which he cleaned the excrement for 5 years) and during his current hobbies (welding, grinding); finally, he had a smoking history of 30 pack-years, stopping 10 years ago. His daily medications were amiodarone, bisoprolol and esomeprazole.
On examination, we found finger clubbing and dry crackles at the lung bases at auscultation; the remainder of the clinical examination was without particularity, we did not find in particular any extra thoracic sign or symptom such as arthralgia, myalgia or a dry eye or dry mouth syndrome.
High-resolution computed tomography (HRCT) showed ground glass opacities surrounding cystic lesions or emphysematous destruction; these anomalies predominated in posterior territories (Fig. 1a, 1b, 1c).
The antinuclear antibodies (ANA) were at 1/200, speckled type and nonspecific; the rest of the autoimmune evaluation was without particularity. The search for bird fancier's precipitin was negative especially for hens' excrements. Bronchoalveolar lavage (BAL) found a macrophagic alveolitis (presence of 180 elements/mm3 including 80% macrophages, 5% lymphocytes, 10% neutrophils and 4.5% polynuclear cells eosinophils) with multinucleated giant cells. The bacteriological and mycobacteriological cultures were sterile. An accessory salivary gland biopsy showed no arguments for Sjogren's syndrome and the Schirmer's test was negative.
Pulmonary function tests were the following: FVC 2.72L or 73% of the predict values, FEV1/VC ratio of 77%, DLCO at 27% of predict values. During a 6 -minute walk test, the patient travelled a distance of 434m with an 83% O2 desaturation.
After a Multidisciplinary Discussion, it was decided to perform a surgical lung biopsy using video-assisted thoracoscopic surgery.
The left lower lobe biopsy led us to find outbreaks of desquamative interstitial pneumonitis with "plump" macrophages associated with emphysema lesions and with numerous giant-epithelioid granulomas without necrosis, sites of dusting. We did not find foamy macrophage that could evoke an amiodarone impregnation (Fig. 2).
Therefore, our conclusion was a Desquamative Interstitial Pneumonia associated with pulmonary granulomatosis.
We studied the mineral particles on the lung biopsy with the following method: the anatomopathological slides were analysed with an electronic scanning microscope (JEOL JSM-6010LV) coupled to a spectrometer EDX (EDS detector Oxford Aztec-DDI X MAXN 50), each mineral particle has a specific spectre. This analysis revealed abnormally high rates of zirconium compounds (5.2% versus 0.0%), aluminium compounds (4.4% versus 0.05%), aluminium oxide (2.0% versus 0.2%) and steel (14.0% versus 0.6%) in our patient compared to a reference population from the Forensic Institute of Lyon (Fig. 3) .
The diagnosis then retained in our patient is a Desquamative Interstitial Pneumonia associated with granulomas secondary to an exposure to metals: Aluminium, Zirconium compound and Steel.
Systemic corticosteroid therapy at a dose of 0.75 mg/kg was introduced for 3 months followed by a progressive decrease over 1 year.
The one-year evaluation showed (i) a clinical improvement: a reduction in dyspnoea to MRC grade 1 and an improvement of 80 meters over the distance covered in the 6-minute walk test; (ii) a functional improvement: the FVC was about 4.15L, i.e. 107% of predict values (gain of 34%) and the DLCO was 44% (gain of 17%); and (iii) a radiological improvement: the HRCT showed a marked improvement with the disappearance of the areas of ground glass opacities, however, there remained emphysematous zones that may correspond to its emphysematous medical history (fig. 1d).