Cholesterol granuloma of the anterior mediastinum with osseous metaplasia

Abstract

Cholesterol granuloma is a well-characterized entity comprised of a foreign-body giant cell-reaction that forms in response to the presence of cholesterol crystals. It is usually found in the middle-ear or mastoid process in patients with diseases associated with chronic inflammation such as cholesteatoma and otitis media. They are rarely seen in the mediastinum. Osseous metaplasia is an exceedingly rare feature of cholesterol granulomas only reported twice in the literature. We report a case of a cholesterol granuloma of the anterior mediastinum with osseous metaplasia in a 75 year-old man that was found incidentally during urgent coronary artery bypass graft surgery.

Primary thymic cholesteroloma: a clinicopathological correlation of four cases of an unusual benign lesion

“…Over the last 10 years, four single case reports of an unusual lesion in the anterior mediastinal compartment have been described under the designation of cholesterol granuloma [2][3][4][5]. The first description of such a case is credited to Luckraz et al [2] who described this unusual lesion in a 74-year-old man who underwent cardiac evaluation.…”

“…Histologically, all three cases shared very similar histological features. In addition to these cases, Ezzat and Alowami [5] described a 75-year-old man with history of angina, hypertension, and peripheral vascular disease who was found to harbor a similar lesion. However, contrary to the cases previously published, this particular case was histologically slightly different as the lesion also showed prominent foci of osseous metaplasia.…”

“…Furthermore, it needs to be emphasized that thymic tumors or tumor-like lesions may correspond to cystic or solid masses. However, to encounter a benign thymic lesion composed exclusively of cholesterol clefts is a rather unusual event even though single case reports have been reported sporadically in the literature [2][3][4][5].…”

Cholesteroloma: a rare thymic pseudotumor

“…In their review of the literature, they have only found four single case reports. [2][3][4][5] These eight previously reported cases occurred in 58-to 75-year-old male patients. Our two patients were also male.…”

“…Only one previously reported case was said to be found in thymic remnant but without illustration. 5 Other cases were only described as located in the region of the thymus, 1 behind the manubrium, 2 adherent to the thymus, 3 or overlying the innominate vein. 4 In conclusion, rarely reported pseudo-tumorous lipid granulomas of the thymus deserve to be better known as possible lucky incidental findings in patients with suspected thymoma.…”