Actinomycosis Mimicking Anastomotic Recurrent Esophageal Cancer on PET-CT

Abstract

We report the PET-CT appearance of actinomycosis in a 76-year-old man with a history of squamous cell carcinoma of the esophagus. The patient was initially treated with neoadjuvant chemoradiation therapy followed by esophagectomy and gastric pullup. Hybrid PET-CT was performed 20 months after completion of treatment using a Siemens Biograph scanner 45 minutes after intravenous administration of 15 mCi of F-18 FDG. PET-CT demonstrated intense hypermetabolism to the left of the anastomosis, corresponding to a soft tissue mass on CT. The patient underwent biopsy of the mass 10 days after PET-CT examination that confirmed actinomycosis with no evidence of recurrent disease.

Unexpected Positron Emission Tomography-PositiveActinomyces-Related Mass of the Bronchial Stump

“…Similar to the few other reports in the literature (5,6), our study shows that PET scanning can support the pathological diagnosis of actinomycosis when the differential diagnosis includes lung cancer. Actinomycosis-related elevation of the SUV was probably due to acute inflammation involving all of the bronchial mucosal layers.…”

Role of Modern Imaging Techniques for Diagnosis of Infection in the Era of18F-Fluorodeoxyglucose Positron Emission Tomography

“…Certain conditions have been shown to increase FDG uptake: (i) benign infection of the lungs or mediastinum (100,102,146,167,179), appendix (82), gall bladder (80,173), and many other organs (64,70,114,135,140); (ii) inflammation without infection, including sarcoidosis (55), pulmonary artery thrombosis (50), abdominal aortic aneurysm (37), and inflammatory arthritis (75); (iii) normal variants, such as brown fat (131), ovaries during ovulation (147), calyceal diverticula (76), the postpartum uterus (93), and activated respiratory muscles in patients with chronic obstructive pulmonary disease (11) or other conditions (172); (iv) atrogenic conditions, such as those related to immunization (165), barium aspiration (51,94), and intravenous line or pacemaker infection (110,159); (v) trauma (67,115), whether spontaneous or following surgery (14,174); and (vi) benign processes such as elastofibroma dorsi (124,163), progressive fibrosis, and benign mesenchymal tumors (30,83,105,161). Although infectious or inflammatory processes frequently pose a diagnostic challenge in the evaluation of patients with cancer (148), the possibility that malignant lesions may also mimic infectious or inflammatory disease (9,28) should not be overlooked.…”

Pulmonary actinomycosis mimicking lung cancer on positron emission tomography

“…[1617] However, only few case reports are present for PET-CT findings of pulmonary actinomycosis. [111213] Thus, limited information on PET-CT findings of pulmonary actinomycosis might lead to unnecessary lung resection in patients with pulmonary actinomycosis due to the concern of lung cancer caused by high FDG uptake on PET-CT. For example, some of our patients underwent surgical resection despite typical CT scans suggestive of pulmonary actinomycosis (lobar, subsegmental, or segmental consolidation with central necrosis), since the attending physicians considered that high FDG uptake on PET-CT favored lung malignancy over pulmonary actinomycosis.…”