Erdheim-Chester disease with cutaneous features in an Indian patient

A 60-year-old Indian woman presented with multiple asymptomatic, firm swellings over the face that had been progressively increasing for the past 3.5 years. She complained of dry cough and dyspnea of 2 years' duration, which was diagnosed as interstitial lung disease (ILD) based on chest radiography and high-resolution computed tomography. Apart from occasional backaches, the patient had no other systemic complaints. The results of the general physical examination was normal, with no lymphadenopathy. Cutaneous examination revealed multiple (5) firm, yellowish to skin-colored well-defined nodules with irregular margins ranging in size from 1 x 1 cm to 4 x 8 cm present over the left periorbital region and right jawline, with overlying telangiectasias on the skin (Figure 1). On examination of the chest, she had generalized rhonchi and crepts; the remainder of the systemic examination results were normal. Fine needle aspiration cytology from the nodule in the periorbital area revealed a dispersed population of spindle cells, numerous foam cells, and giant cells suggestive of xanthogranuloma. Histopathology from the nodule on the jawline showed abundant foamy histiocytes in the dermis with few multinucleated giant cells and lymphocytes (Figure 2). The foamy histiocytes were periodic acid-Schiff-positive. On immunohistochemistry, histiocytes were CD68-positive. Findings of routine investigations including hemogram, peripheral blood smear, and blood chemistry were normal. Radiography of the lumbosacral spine showed mixed osteolytic and osteosclerotic lesions involving L5-S1, the left sacroiliac joint, and the left iliac blade. Findings from radiography of the long bones and skull were normal. Contrast-enhanced computed tomographic scan of the abdomen and pelvis showed areas of osteolysis, with marginal sclerosis present bilaterally that involved the iliac blades and the right half of the sacrum. A methylene diphosphate bone scan revealed increased tracer uptake seen at the fifth lumbar vertebrae, bilateral sacroiliac bone, and left iliac bone and areas of photopenia in sacrum. Bone marrow aspiration from the sternum showed normal cells with a normal erythroid-to-myeloid ratio. Ultrasonographic B scanning of the eyes showed no retro-orbital involvement. Erdheim-Chester disease was diagnosed in this patient on the basis of diagnostic histopathology, radiologic features involving bones, and ILD and treatment with 40 mg oral prednisolone daily was started. Surgical debulking of her skin lesions was planned, but the patient refused due to her worsening ILD.