A 34-year-old woman was transferred from Inukjuak, a first nation community in Northern Quebec, to the Montreal General Hospital in Montreal, Quebec, Canada. Her respiratory symptoms included dry cough and dyspnea II/V on Medical Research Council dyspnea scale. She also complained of severe middle back pain radiating to her left ribs that began two months before admission. She smoked a mean of 20 cigarettes per day for 20 years and denied alcohol or drug abuse. Her past medical history was limited to a remote exposure to tuberculosis that did not required treatment. Prior to onset of symptoms, the patient was not taking any medication but began using acetaminophen in the four weeks before admission.
Physical examination was only significant for paraspinal tenderness between T7 and T9 vertebrae. Neurological examination did not reveal motor or sensory dysfunction. Chest auscultation identified normal breath sounds with no adventitious sounds in the absence of cyanosis or clubbing. Laboratory results were within normal values and showed no evidence of hyponatremia, elevated white blood count, or increased LDH. Serum protein electrophoresis and immunofixation were normal. Chest X-ray showed a diffuse bilateral nodular interstitial pattern. A computed tomodensitometry (CT) in contrast to the chest was performed and revealed bilateral reticular-nodular disease in the lungs with the presence of cystic lesions that speared the lung bases (Figure 1(a)). As shown in Figure 1, no lymph node enlargement or pleural effusions were observed. The bone image on the same CT showed a solitary osteolytic lesion at T8 vertebral body and right pedicle, with a two-millimeter margin between the lesion and the spinal cord (Figure 2).
Pulmonary function tests (PFT) demonstrated a restrictive and a marked reduction in diffusing capacity (DLCO 63.5%). A bronchoscopy was performed to identify the cause of the diffuse micronodular lesions in the lungs. Results were negative for bacterial, viral, and Ziehl-Neelsen stains and grocott stains were negative for tuberculosis and pneumocystis jiroveci pneumonia, respectively. A transbronchial biopsy was performed and demonstrated eosinophilic granuloma with the presence of numerous bean-shaped cells with lobulated nuclei. These cells were aggregately stained and were immunohistochemically positive for S100, langerin, and CD1 consistent with the diagnosis of LCH.
To eliminate a neoplastic condition in T8 vertebra, an echo-guided bone biopsy was performed. Pathological findings confirmed the diagnosis of LCH in the body of the vertebra. Based on the absence of both bone collapse and neurological deficits, orthopedic decompression/fixation surgery was not undertaken. Conservative management with smoking cessation and close follow-up was proposed to the patient.
After three months, the dyspnea was reduced to an I/V level on the MRC breathlessness scale, and the diffuse interstitial lesions were no longer present on chest X-ray. The patient reported decreased use of acetaminophen for the back pain, which started to improve four weeks following smoking cessation.
After an 18-month follow-up, the patient experienced a complete resolution of all her symptoms. A repeated CT scan of the chest showed significant decrease of the multiple lung nodules and the bone view revealed an 80% bone regeneration at the site of the initial osteolytic lesion (Figures 1 and 2). Lastly, her lung function completely normalized. Following a final remote interview with the patient four years after this episode, the patient did not resume smoking and remains symptom-free.