Unusual presentation of thymic carcinoma: hypertrophic osteoarthropathy

Abstract

Hypertrophic osteoarthropathy is characterized by clubbing and periosteal new bone formation along the shaft of the long bones of the extremities. Although various intrathoracic malignancies have been associated with the development of HOA, it has been extremely rare for HOA to occur in a patient with a thymic carcinoma. Recently, we experienced a 63-year-old woman diagnosed as a thymic carcinoma with hypertrophic osteoarthropathy. She had both digital clubbing and cortical thickening in her lower extremities identified radiologically. We herein describe this case with a review of the literature.

Figure 1.

Clubbing of fingers.

Figure 2.

(A) Bone scan shows diffusely increased uptake along the cortical portions of both lower extremities. (B) Left tibia and fibular X-ray films demonstrate diffuse cortical thickening (arrows).

Figure 3.

Chest PA view shows left mediastinal bulging (arrows).

Figure 4.

At carinal level, chest CT scan shows a heterogeneous enhancing mass (arrows) with pericardial effusion in anterior mediastinum.

Figure 5.

Irregular nests of malignant tumor cells with some necrotic area. Tumor cells show poorly differentiated appearance with hyperchromatic and irregular nuclei and moderate amount of eosinophilic cytoplasm. Mitotic figures are frequently seen (Hematoxylin & Eosin, ×200).