A rare case of giant cell tumor of the anterior rib presenting as a breast mass

Abstract

Initial diagnostic ultrasound of a 22-year-old female patient presenting with a palpable breast mass revealed a suspicious mass initially thought to arise from the breast. However, follow-up diagnostic mammography was normal without evidence of the 5 cm mass seen on ultrasound, and pathology results from ultrasound-guided core needle biopsy raised suspicion for giant cell tumor, making chest wall origin of the mass more likely. Further CT and MRI imaging indeed revealed a locally invasive mass arising from the anterior fifth rib. The patient was treated with denosumab to decrease tumor burden before surgery, and subsequently underwent successful surgical resection of the tumor with mesh overlay and flap reconstruction of the chest wall defect. This case highlights the importance of keeping chest wall lesions in the differential for lesions presenting clinically as breast lesions. Despite the rarity of giant cell tumor of the anterior rib and its unusual presentation as a breast mass, appropriate diagnostic imaging work-up allowed for successful diagnosis and treatment in this case.

Keywords: Breast imaging; Chest wall lesion; Giant cell tumor.

Fig. 1

Anti-radial and radial ultrasound images of a mass in the left breast at 6 o'clock 7 cm from the nipple. The mass measures 5.1 × 4.5 × 3.3 cm and is irregular and hypoechoic with indistinct margins.

Fig. 2

Further US examination of the mass (white arrows) revealed its proximity to an anterior rib (white star, A) as well as an anechoic cardiac chamber just deep to it without intervening chest wall musculature (B), with confirmatory color filling of the cardiac chamber with Doppler (C).

Fig. 3

US-guided core needle biopsy was taken of the mass with the biopsy needle parallel to the chest wall. (A) demonstrates the biopsy needle within the mass with an open trough, and the (B) demonstrates the biopsy needle after the device was fired.

Fig. 4

Mediolateral oblique, cranio-caudal, exaggerated cranio-caudal medial, and exaggerated cranio-caudal lateral views of the left breast are normal without evidence of the mass seen on ultrasound.

Fig. 5

Axial contrast-enhanced chest CT (A) demonstrates a heterogeneously enhancing anterior chest wall mass (white arrow) with local invasion of the chest wall musculature and pleura, as well as proximity to the left ventricular apex concerning for pericardial invasion. Coronal bone window CT image clearly shows the mass arising from the anterior fifth rib (black arrow).

Fig. 6

The mass demonstrates intermediate signal on axial T1-weighted MRI (A), heterogenous enhancement on axial T1-weighted post-contrast MRI (B), and heterogenous T2 hyperintensity on coronal T2-weighted MRI (C, white arrow).

Fig. 7

Initial axial CT of the mass (A) compared to axial CT of the mass taken 3 months later after 3 cycles of denosumab (B), demonstrating decrease in size from 5.8 × 4.5 cm to 4.4 × 3.3 cm as well as increased peripheral sclerosis.