Clinical History
This is a 24 year-old female patient with chondrosarcoma. Correlation is made with a bone scan and thallium scan. No other imaging studies are available to correlated anatomy morphology.
Technique
The patient was administered 10.7 mCi of 18F-FDG and 45 minutes later whole body scanning was performed from the skull base to the upper thighs.
Findings
Incidental note is made of an area of increased activity over the left antecubital fossa at the patient's IV site consistent with extravasation of FDG.
1. There is normal physiologic uptake of FDG in the oral pharynx, larynx, heart, left kidney, and gastrointestinal tracts with excretion into the urinary bladder.
2. There is increased activity in the right renal pelvis and proximal ureter which may be physiologic in nature however it may represent an element of left ureteral obstruction.
3. There is a large amorphous area of increased uptake of FDG involving the right hemipelvis which extends throughout the right innominate bone into the soft tissues anteriorly to what is thought to be near the anterior pelvic wall. It also extends into the soft tissues anteromedially to right of the midline. The greatest level of uptake is seen along the peripheral margins of the this amorphous area and these are most prominent along the anterior surface and the posterior aspect extending from the osseous structures along the posterior aspects of the mass like structure in 3 or 4 curvilinear elements. In addition, there are several foci of higher increased uptake in the superior aspects of the mass like region. These foci of greater uptake generally range greater than 3.0 SUV with the highest level of uptake identified at a maximum SUV of 5.5. No other areas of increased uptake are identified outside of the right hemipelvis as described.
Impressions
1. LARGE AMORPHOUS AREAS OF INCREASED UPTAKE IN THE RIGHT HEMIPELVIS WHICH APPEARS TO INVOLVE THE INNOMINATE BONE AND THE SOFT TISSUES OF THE RIGHT PELVIS.
2. ELEVATED INCREASED ACTIVITY IN THE RIGHT RENAL PELVIS WHICH MAY BE ENTIRELY PHYSIOLOGIC IN NATURE. HOWEVER, IN LIGHT OF THE LARGE AMORPHOUS MASS LIKE STRUCTURE IN THE RIGHT PELVIS AN ELEMENT OF RIGHT URETERAL OBSTRUCTION IS CONSIDERED MORE LIKELY.
Thallium-201 Tumor Scan
Clinical History
The patient is a 24-year-old female with a pelvic mass.
Technique
The patient was administered 4.86 mCi of thallium-201 chloride, and 20 minutes and two hours thereafter, anterior and posterior images were obtained.
Findings
There is an area of mild increased activity noted in the right hemipelvis, which corresponds with the area of increased uptake on the bone scan. There appears to be a bony as well as a large soft tissue component. Areas of contoured regions of interest over the abnormally increased uptake in the right hemipelvis as well as the corresponding contralateral left pelvis. The corresponding ratio was calculated to be 1.62 at 20 minutes and 1.46 at two hours.
Impressions
MILD INCREASED UPTAKE IN THE RIGHT HEMIPELVIS, CONSISTENT WITH TUMOR, WITH A LARGE SOFT TISSUE COMPONENT.
Bone Scan
Clinical History
A 24-year-old female with pelvic mass. No prior study is available for comparison.
Technique
Twenty millicuries of technetium-99m MDP was administered to the patient. Blood pool images as well as anterior and posterior planar images were obtained.
Findings
There is otherwise normal uptake of labeled phosphorus throughout the axial and appendicular skeleton. There is normal physiologic activity noted in the kidneys with excretion into the urinary bladder. Blush is noted on all three phases of today's scan in the region of the right iliac wing. A mottled well-demarcated area is noted involving the right iliac wing. Note is made of increased activity in the knees bilaterally, right greater than left, involving the distal femur and proximal tibias.
Impressions
WELL-DEMARCATED MOTTLED AREA OF INCREASED ACTIVITY IN THE RIGHT ILIAC WING IS NOTED AND SUSPICIOUS FOR NEOPLASTIC INVOLVEMENT. POSSIBILITIES INCLUDE OSTEOGENIC SARCOMA, EWING'S SARCOMA, OR CHONDROSARCOMA.
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PET Chondrosarcoma scan.
