FDG PET/CT detection of intussusception caused by aggressive fibromatosis

FDG PET/CT in a Case of Gardner Syndrome

ABSTRACT

Gardner syndrome is characterized by multiple intestinal polyps and extraintestinal lesions. We describe FDG PET/CT findings of the extraintestinal lesions in a patient with Gardner syndrome. FDG PET/CT showed 2 hypermetabolic desmoid tumors in the abdominal wall, sclerotic areas with multifocal activity in the maxilla and mandible, multiple osteomas in the bilateral parietal, left frontal, sphenoid and ethmoid bones, an impacted tooth in the right maxilla, and bone islands in the T2 and T5 vertebral bodies. Extraintestinal involvements in Gardner syndrome can precede intestinal polyposis. Therefore, familiarity with FDG PET/CT findings of extraintestinal manifestations is helpful for early diagnosis.

Abdominal Wall Desmoid Fibromatosis Mimics Sarcoma With Intense FDG Uptake on FDG PET/CT

We present the case of an abdominal wall soft tissue mass with intense FDG uptake in a 61-year-old man with unintentional weight loss. The appearance of this mass and high focal FDG uptake mimics high-grade sarcoma on (18)F-FDG PET/CT. However, the final excisional histopathological diagnosis was desmoid fibromatosis.

Imaging features of superficial and deep fibromatoses in the adult population

The fibromatoses are a group of benign fibroblastic proliferations that vary from benign to intermediate in biological behavior. This article will discuss imaging characteristics and patient demographics of the adult type superficial (fascial) and deep (musculoaponeurotic) fibromatoses. The imaging appearance of these lesions can be characteristic (particularly when using magnetic resonance imaging). Palmar fibromatosis demonstrates multiple nodular or band-like soft tissue masses arising from the proximal palmar aponeurosis and extending along the subcutaneous tissues of the finger in parallel to the flexor tendons. T1 and T2-weighted signal intensity can vary from low (higher collagen) to intermediate (higher cellularity), similar to the other fibromatoses. Plantar fibromatosis manifests as superficial lesions along the deep plantar aponeurosis, which typically blend with the adjacent plantar musculature. Linear tails of extension (“fascial tail sign”) along the aponeurosis are frequent. Extraabdominal and abdominal wall fibromatosis often appear as a heterogeneous lesion with low signal intensity bands on all pulse sequences and linear fascial extensions (“fascial tail” sign) with MR imaging. Mesenteric fibromatosis usually demonstrates a soft tissue density on CT with radiating strands projecting into the adjacent mesenteric fat. When imaging is combined with patient demographics, a diagnosis can frequently be obtained.

Desmoid tumour (aggressive fibromatosis) of the colon mimics malignancy on dual time-point 18F-FDG PET/CT imaging

A 58-year-old female who presented with a lower gastrointestinal bleed was referred for an (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT after a colonoscopy revealed a submucosal mass in the ascending colon. The PET/CT confirmed the presence of an FDG-avid mass in the ascending colon with no other FDG-avid abnormalities. Dual time-point imaging was performed and showed a significant increase in FDG uptake in the mass, which raised strong suspicion of a colon malignancy. Although an initial biopsy of the mass did not show evidence of neoplasia, a decision was made to proceed with a right hemicolectomy based on high clinical and imaging suspicion of malignancy. Histological evaluation of the hemicolectomy revealed a benign colon desmoid tumour.