Imaging of Fibrous Dysplasia Protuberans, an Extremely Rare Exophytic Variant of Fibrous Dysplasia.

This paper details the case report of a 26-year-old man who presented with a growing right-sided skull mass evaluated with ultrasound, non-contrast CT, contrast-enhanced MRI and 99mTc-MDP whole body bone scan with SPECT/CT. These studies suggested a broad differential diagnosis favoring benign osseous lesions. Given a more recent increase in the rate of growth, headache and large size, the lesion was excised via craniotomy followed by cranioplasty. Pathology confirmed fibrous dysplasia (FD) as the diagnosis. Interestingly, this report is the imaging evaluation of the exophytic subtype of FD, the so-called FD protuberance, an extremely rare variant of FD, of which only two case reports are found in the literature.

Focal uptake of Tc-99m MDP in a gossypiboma.

A 51-year-old Korean woman with a history of breast cancer underwent screening bone scintigraphy, which revealed minimal soft tissue uptake of Tc-99m methylene diphosphonate (MDP) in the right lower quadrant. CT and plain films confirmed that the uptake was due to a retained surgical sponge or gossypiboma. The incidence of gossypibomas has been reported at high as 1 in 1000 to 15,000 intra-abdominal operations. The natural progression of an aseptic gossypiboma is a foreign body reaction and granuloma formation. This inflammatory granulomatous reaction is the most likely cause of the extraosseous accumulation of Tc-99m MDP. This entity should be added to the already extensive list of etiologies of extraosseous MDP accumulation.

Persistent F-18 deoxyglucose and Tc-99m methylene diphosphonate uptake in a lower extremity radiation port.

Four years after radiation therapy to the lower extremity for a bone metastasis, persistent F-18 FDG and Tc99m MDP uptake were noted in the radiation port. Presumably ongoing inflammatory cellular processes accounts for this finding.

Sacral Fatigue Fracture in a Military Recruit.

A 19-year-old male military recruit presented with 3 weeks of persistent left hip and groin pain after abnormally twisting his hip during a hike. Initial radiographs were interpreted as negative. He subsequently underwent a bone scan which revealed linear left sacral uptake along or paralleling the sacroiliac joint. Differential diagnostic considerations included unilateral sacroiliitis and sacral fracture. SPECT/CT was performed which confirmed left sacral fatigue stress fracture. Transitional lumbosacral anatomy was evident on radiographs with pseudoarticulation of the transitional left S1 transverse process with the sacrum. We postulate this predisposed the recruit to sacral fracture.

A Unique Case of Increased 18F-FDG Metabolic Activity in the Soft Tissues of the Bilateral Upper Thighs Due to Immunizations in a Pediatric Patient.

A case of a 7-month-old white female who was referred for 18F-fluorodeoxyglucose (FDG) Positron emission tomography/computed tomography (PET/CT) initial evaluation of a lytic skull lesion with presumed diagnosis of Langerhans cell histiocytosis is described. Incidentally, she was found to have hypermetabolic nodules in the soft tissues of her anterior thighs.

A case of bronchobiliary fistula in the setting of adult polycystic kidney and liver disease, with a review of the literature.

A case of bronchobiliary fistula (BBF) was demonstrated in the setting of polycystic kidney and liver disease (PCKLD) by hepatobiliary scintigraphy. High-resolution noncontrast computed tomography through the liver showed a polycystic liver. A calcified cyst adjacent to the dome of the liver appeared to have a fistulous connection with the lung on coronal reconstructions. Hepatobiliary scan confirmed the fistulous connection. In a review of the literature, BBF has been associated with hydatid cyst disease, trauma, postsurgical states, and malignancy. As demonstrated by this case, BBF is difficult to diagnose and requires a high clinical index of suspicion. Hepatobiliary scintigraphy is the imaging modality of choice to confirm BBF, and PCKLD should be added to the list of antecedent etiologies.

PET/CT appearance of acute pyelonephritis.

An 18-year-old male patient with a history of Ewing sarcoma originally involving the right ilium was evaluated with an FDG PET/CT scan to evaluate the effect of salvage therapy after standard treatment failed and disease progressed to involve the right T12 pedicle. Autologous stem cell transplantation and cyberknife therapy resulted in mixed tumor response, with incidental note made of prominent areas of cortical FDG avidity in the right kidney. These regions demonstrated focal hypoenhancement on the corresponding diagnostic contrast-enhanced CT, which additionally demonstrated peripheral enhancement spanning the length of the right ureter. Clinical workup produced a diagnosis of acute pyelonephritis.