Case report:
A 50-year-old woman with a history of hypothyroidism, presented with a recurrent pain and swelling of the left knee and the right breast. Physical examination found high blood pressure, normal cardiac auscultation and a normal EKG. Pulmonary auscultation found fine crackles in both lower lobes with no history of cough or breathlessness. The abdomen examination found hepatomegaly. No enlarged peripheral lymph nodes neither thyroid nodules were found. She had xanthelasma of the right upper eyelid, an erythematous plaque of the inferior medial quadrant of the left breast with no nodules or mass.
Standard radiography of the knee showed an osteolytic and heterogenous lesion of the proximal tibia and fibula metaphyses. Bone scintigraphy showed increased tracer uptake of the humeri diaphysis, both iliac bones, distal femora extremity and tibias (figure 1a,1b,1c). Echography of thyroid glands showed pseudo-nodular heterogenous lesions. The computed tomography (CT) showed a small pericardial effusion and a moderate encapsulated right pleural thickening and effusion associated to a bilateral and diffuse septal thickening and a micronodule in the apical segment of the upper right pulmonary lobe. It also showed an infiltrative process of subcutaneous tissues of the breasts, tissular infiltration in the retroperitoneum, tissue thickening around the aorta from its thoracic portion to the sub-renal portion along with tissue infiltration of the inferior vena cava and the kidney pedicules and peri-renal fascia thickening and ureteral dilation. The CT also showed hepatomegaly (Figure 2a,2b,2c). Mammography was normal. Pulmonary function tests found a mixed pattern (forced vital capacity: 47%) with reversible obstruction.
During the disease course the patient had an ischemic stroke in the territory of the middle cerebral artery confirmed by magnetic resonance imaging (MRI) that showed no other abnormalities, the cardiac echography showed a small pericardial effusion and no atrioventricular mass. Our patient had no central nervous system neither ocular involvement as demonstrated by cerebral MRI imaging.
The biopsy of the retroperitoneum tissue thickening showed fibrosis with inflammatory infiltrate including foamy macrophages along with Touton giant cells. Pleural biopsy found fibrotic pachypleuritis. Immunohistochemistry was positive for CD68 and negative for CD1a and PS100 (Figure 3a, 3b, 3c).
The clinical presentation and the histopathologic aspects corroborated the diagnosis of ECD.
Because of the multi-organ involvement, the patient received a treatment regimen of prednisone at the dose of 1mg/kg/day with infusion of infliximab 5m/kg/ 6 weeks associated to 15 mg per week of methotrexate.
The follow up was mainly by clinical assessment and a PET-CT is intended within 6 months of treatment.