Progressive intraparenchymal lung nodules dissemination in a heavy smoker and seropositive rheumatoid arthritis suspected of tuberculosis relapse.

Anthony Caplan first described rheumatoid lung nodules associated with pneumoconiosis in coal-miners (Caplan, 1953). Intraparenchymal lung nodules were later described in rheumatoid arthritis (RA) patients who were never exposed to coal dust and/or without pneumoconiosis. Rheumatoid lung nodules are usually detected in unselected patients: 0.2% in chest radiography and 4% in high-resolution computed tomography (Nannini et al., 2008). Patients could be reluctant to perform surgical lung biopsy for an accurate histopathological diagnosis. We present a peculiar association between a seropositive RA and a presumptive active tuberculosis (TB) disease in a 59-year-old male patient, ex-smoker with a previously healed pulmonary TB disease. The purpose of this report is to describe an unusual case of a presumptive relapse of the nodular TB disease, which progressed to an extensive nodular bilateral dissemination under anti-tuberculosis therapy, mimicking a metastatic carcinoma. The diagnosis of rheumatoid necrobiotic lung nodules was confirmed after open biopsy left pulmonary was performed. Formalin-fixed paraffin-embedded pulmonary rheumatoid nodules were processed for histology and stained with Masson's trichrome. Central structure of the removed pulmonary nodules is typical of a rheumatoid nodule with central necrosis surrounded by a palisade of macrophages. The accumulation of anthracotic pigment was noticed inside the pulmonary nodules in a RA patient without professional exposure to coal or mineral dust. This rare entity is an appearance of the rheumatoid nodules lung syndrome and anthracosis in a heavy tobacco former smoker.