Linh Ho

Primary spinal epidural non-Hodgkin lymphoma demonstrated by FDG PET/CT.

We report the F-18 fluorodeoxyglucose positron emission tomography/computed tomography appearance of a biopsy-proven primary epidural non-Hodgkin lymphoma involving the lower cervical and upper thoracic spine with a small hypermetabolic right middle lobe nodule in a 33-year-old man. The HIV-positive patient presented with mid- to low back pain for several days, which progressed to lower extremity weakness and urinary retention. Primary spinal epidural non-Hodgkin lymphoma is a rare form of malignancy, constituting approximately 0.1% to 3.3% of all lymphomas. In our case, the primary tumor appears as an intensely hypermetabolic soft-tissue mass involving the posterior epidural space from C6 through T9 levels.

Left maxillary sinus malignant fibrous histiocytoma on FDG PET-CT.

We report the PET-CT appearance of a newly diagnosed malignant fibrous histiocytoma, involving the left maxillary sinus with pulmonary metastases, in a 69-year-old man. Initial staging PET-CT images demonstrated a large, intensely hypermetabolic mass involving the entire left maxillary sinus, consistent with the primary tumor. In addition, there were several hypermetabolic pulmonary nodules bilaterally, most consistent with pulmonary metastases. Malignant fibrous histiocytoma is a high-grade and aggressive sarcoma and relatively rare in the head and neck region, and very rare in the maxillary sinus. The main management includes surgical resection with or without postoperative chemoradiation therapy.

FDG PET/CT imaging in granulomatous changes secondary to breast silicone injection.

An 81-year-old woman with history of silicone injection and saline bag implants in both breasts was diagnosed over 30 years later with lobular carcinoma in her right breast and underwent right mastectomy. She was referred to our institution for a restaging PET-CT examination. The PET-CT images showed multiple lobulated/nodular, hypermetabolic, soft-tissue masses, and scattered calcifications involving the right chest wall, left breast, and bilateral axillary regions. Biopsy was consistent with silicone-related granulomatous tissue. The largest soft-tissue mass in the

Renal metastasis from primary colon cancer on FDG PET-CT.

We report the PET-CT appearance of a metastasis from a primary colon cancer to the right kidney in an 84-year-old woman with a history of moderately differentiated adenocarcinoma of the cecum. The patient underwent right hemicolectomy and chemotherapy. Restaging PET-CT study, 4 months after her last chemotherapy, demonstrates a hypermetabolic soft-tissue mass in the inferior pole of the right kidney. The patient subsequently had a right partial nephrectomy. The pathology was consistent with metastatic colonic adenocarcinoma. Renal metastasis from primary colon cancer is very rare.

Thyroid metastasis from primary renal cell cancer on FDG PET/CT.

We report the PET/CT appearance of metastasis from primary renal cancer to the thyroid in a 52-year-old man with a history of right renal cell carcinoma, status postright nephrectomy, recently presented biopsied-proven metastatic lesion in his left thyroid lobe. Restaging PET/CT study demonstrates a 1.4 × 0.9 cm hypodense, moderately active lesion in the left thyroid lobe with a maximum SUV of 2.8. No other abnormal hypermetabolic lesion is seen in the right renal surgical bed or the remaining body. The patient has subsequently treated with Sutent (Sunitinib).

Intramuscular metastasis of endometrial carcinoma on FDG PET/CT.

We report the F-18 FDG PET/CT appearance of biopsy proven intramuscular metastasis from primary endometrial carcinoma. The patient is a 70-year-old woman initially diagnosed with endometrioid adenocarcinoma, status post total abdominal hysterectomy, bilateral salpingo-oopherectomy and pelvic node dissection. Restaging PET/CT study performed 1 year later demonstrated extensive metastatic disease involving the intramuscular region of the right neck, right kidney, pancreas, left adrenal gland, lungs, lymph nodes, and bone. The lesion in the right neck intramuscular region was subsequently biopsied and interpreted as consistent with metastasis from an endometrial primary. Metastasis to the skeletal muscle from the primary endometrial carcinoma is a rare entity. Knowledge of this rare metastatic site will help the interpreting physician make the correct diagnosis.

F-18 fluorodeoxyglucose positron emission tomography/computed tomography imaging in left thigh intramuscular myxoma.

We report F-18 FDG PET-CT appearance of biopsy-proven intramuscular myxoma (IM) in a 69-year-old woman who presented with a left thigh mass. The tumor appears as a well-defined, hypodense mass with thin septation on CT images and mild uptake on PET images. IMs are rare benign myxoid tumors characterized by a paucity of cells, diminished vascularity, and minimal mitotic figures. They most often present as slow-growing, painless, deep-seated intramuscular masses. The mainstay of treatment is surgical resection.

Multi-level lumbar Baastrup disease on F-18 FDG PET-CT.

Abstract:We report the positron emission tomography-computed tomography appearance of Baastrup disease in the L2–L5 interspinous ligament region in a 79-year-old woman with a history of moderately differentiated lobular breast carcinoma. The patient is status post bilateral mastectomies, on tamoxife

Recurrent adult Wilms tumor with extensive metastases on FDG PET-CT.

Abstract: We report the PET-CT appearance of recurrent Wilms tumor in the surgical bed with multiple metastatic sites in a 30-year-old man. He was initially diagnosed with Wilms tumor in the right kidney with involvement of the right adrenal gland and right renal vein into the inferior vena cava, for which he underwent a right nephrectomy, right adrenalectomy, and retroperitoneal lymph node dissection. Three months later, a restaging PET-CT study demonstrated multiple hypermetabolic lesions in the surgical bed region, the left adrenal gland, liver, thoracolumbar spine, retroperitoneal lymph nodes, and peritoneum.

18F-FDG PET/CT appearance of metastatic brachial plexopathy involving epidural space from breast carcinoma.

Patient is a 74-year-old woman with a history of breast carcinoma and known metastatic brachial plexopathy and pulmonary and mediastinal nodal involvement. She had bilateral mastectomies 5 years ago and is currently on chemotherapy. A 6-month follow-up PET/CT study demonstrated no significant interval change in intensity of the previously evident hypermetabolic activity of the brachial plexopathy. However, this activity has extended superiorly and medially involving the right lateral aspect of the epidural space at the C5-6 level, consistent with epidural involvement. In addition, the hypermetabolic activity of the pulmonary and mediastinal metastases has also increased, consistent with interval progression of the disease.