Not All That Shines on a PET Scan Is Cancer: A Silicone-Induced Granuloma Masquerading as Malignancy

Abstract

PET/CT scans are frequently used in the initial workup of suspicious lesions but not all that lights up on a PET is cancerous. We wish to discuss a case of silicone-induced granuloma mimicking malignancy and the role of other imaging modalities for further workup.

Keywords: false positives; malignancy; pet imaging; radiology; siloconomas.

Figure 1

(A) Mammogram demonstrating extracapsular rupture of the right breast, (B) mediastinal window chest CT demonstrating Linguine Sign of the left breast implant, (C) chest CT showing an 18 mm × 14 mm nodule in the right middle lobe causing concern for malignancy, and (D) the same image showing a 17 mm × 14 mm spiculated left lung nodule with concern for breast involvement.

Figure 2

PET/CT demonstrating increased uptake with multiple mediastinal lymph nodes with a nodule in the right middle lobe and a spiculated left lung nodule with concern for breast involvement: the black arrows point to areas of suspicion.

Figure 3

Non-caseating granuloma from a CT-guided biopsy of the left lung nodule showing an asteroid body (black arrow), a typical finding in granulomas.