Case Report # []

Submitted by: Jason Pearce, MS IV

Faculty reviewer: Sandra. A. A. Oldham M.D.

Date accepted: August 30, 2007

Radiological Category: Principal Modality (1):

Principal Modality (2): CT/ CXR/Nuclear

MRI

Case History

Patient is a 49 year old hispanic woman presenting to the hospital with a 2 month history of headaches. Headaches were noted to be increasing in intensity. Over the same time period she has had episodes of blurred vision, hearing problems described as “hearing waves,” and sometimes feeling like she is in a tunnel. She denies any photophobia, N/V, rhinorrhea, tearing, fevers, neck pain or any additional stresses in her life. She also noted some lower back pain and hip pain. This pain has been present for a couple of months and hasn’t really changed in intensity and is moderately controlled by Advil. She attributes this pain to getting older and being overweight.

A significant piece of PMH is being withheld.

T1 MRI w/o contrast

T1 MRI w/contrast

T2 MRI

CXR

CT w/contrast

CT Abdomen

CT Pelvis

Bone Scan

• Primary Bone Tumor

• Multiple Myeloma

• Metastatic Cancer

• Fibrous Dysplasia

Which one of the following is your choice for the appropriate diagnosis?

Test Your Diagnosis

CT Abdomen

These images belong to two other patients. The PMH not given earlier is this pt had hx of

renal cell carcinoma.

Findings:MRI: morphologically normal brain. No intracranial mass lesions.

There is a marrow replacing expansile mass in bone posterior to right occipital lobe measuring 2.4 x 1.4 x 2.9cm. There is mild expansion of inner table of the calvarium w/ extension into cranial vault. A second marrow replacing mass in noted in left parietal bone measuring 5mm in diameter.

CT Abd/Pel: showed a 5.7 cm mass in right adrenal gland, 7.8cm lytic lesion in right ilium at the sacroiliac joint, a 3cm lytic lesion in left acetabulum, all characteristic of metastatic disease.

Bone Scan: There are hot lesions in right iliac bone, a horizontal sacral fracture, a focal area in left acetabulum, lytic lesion in occipital bone on right side and a focal area on left 6th rib.

CXR: bilateral pulmonary metastases, surgical clips in abdomen.

Differentials:

Findings and Differentials

• Multiple Myeloma

• Metastatic Cancer

• Primary Bone Cancer

• Fibrous Dysplasia

Multiple Myeloma • Neoplastic proliferation of a single clone of plasma cells producing a monoclonal

immunuglobulin found within the bone marrow. • Median age of diagnosis is 66 years of age, w/ less than 10% prior to age of 50.• Clinically presents as bone pain, unexplained anemia, symptoms of hypercalcemia,

renal failure and recurrent infections.• Lytic bone lesions caused by both rapid growth of myeloma cells inhibiting normal bone-

forming cells, and production of substances that activate osteoclasts.• Do not use bone scans to evaluate myeloma. Cytokines secreted by myeloma cells

suppress osteoblast activity; therefore, typically, no increased uptake is observed. • Lesions are seen as focal or diffuse areas of hypointensity on T1-weighted images and

as areas of intermediate or high signal intensity on T2-weighted images. Myeloma

lesions tend to enhance somewhat with gadolinium.• In our case it would be difficult to differentiate this from metastasis, but the degree of

enhancement by gadolinium may be slightly less.

Discussion

Fibrous Dysplasia• Fibrous dysplasia is a skeletal developmental anomaly of the bone-forming mesenchyme

that manifests as a defect in osteoblastic differentiation and maturation. Virtually any

bone in the body can be affected.• Medullary bone is replaced by fibrous tissue, which appears radiolucent on radiographs,

with the classically described ground-glass appearance.• Most commonly found in persons aged 3-15 years.• 70-80% of fibrous dysplasias are monostotic; present with pain or a pathologic fracture • 20-30% of fibrous dysplasias are polyostotic; often involving the facial bones and skull.• It also occurs in an isolated craniofacial form. In the isolated variety, no extracranial

lesions are present.• On T1-weighted MRIs, the lesion has low-to-intermediate signal intensity equal to that of

muscle. T2-weighted images also show low signal intensity owing to the high content of

collagen and bone.

Discussion

Bone Metastases• Metastases involve bone by means of 3 main mechanisms: (1) direct extension, (2)

retrograde venous flow, and (3) seeding with tumor emboli via the blood circulation. • Seeding occurs initially in the red marrow; this process accounts for the predominant

distribution of metastatic lesions in the red marrow–containing areas in adults.• Bone metastasis can occur from almost any malignancy, but the most common are

from the breast, kidney, lung, prostate, and thyroid. • Lesions are lytic (bone loss), blastic (increased bone) or both.• Lytic lesion: lung, kidney, thyroid, and breast Blastic: prostate & treated breast ca• Vascular metastasis include: ovarian, renal, thyroid, and melanoma.• Bone metastases usually affect axial skeleton, appendicular skeleton later (and

much less frequently), and to the distal extremities is extremely rare.

Diagnostic Imaging of suspected bone metastasis include:

Plain Films: useful because most people present w/ pain to a particular bone,

drawbacks are that the lytic bone metastases must be greater than

1 cm and have destroyed 30-50% of the bone density in order to be

seen by x-ray.

Discussion

Bone Metastasis

Bone Scan: good for detecting lesions prior to evidence on plain film, and for

ability to view all bones at one time, however bone scans are only

specific for bone turnover, not malignancy.

CT/MRI: useful for equivocal changes on plain film. MRI can show bone changes

even before metabolic abnormalities are seen on bone scans. Lesions

are seen as focal or diffuse areas of hypointensity on T1-weighted

images and as areas of intermediate or high signal intensity on T2-

weighted images.

Discussion

Renal Cell Carcinoma (RCC)

Epidemiology: 50,000/13,000 diagnoses and deaths annually in U.S. No differences between race or gender. Predominately found in 6th – 8th decade of life. 85% of primary renal cancers (Transitional cell carcinoma 8%, Nephroblastoma & Wilm’s Tumor among children 5-6%)

Risk Factors: Smoking – 2 fold increased risk, found in 1/3 of reported cases Obesity Dialysis – increased, primarily after 8-10 years of dialysis VonHippel-Lindau disease – 40-60% will develop RCC Family History

Symptoms: completely asymptomatic (often pts present w/ metastatis) flank pain, abdominal mass, hematuria (all 3 in only 8-10%) anemia, HTN, fever of unknown origin paraneoplastic syndromes (erythrocytosis, PTHrp, renin, etc.)

Discussion

Renal Cell Carcinoma (RCC)

Diagnosis:

1. First choice is usually CT w/ contrast *** 95% of RCCs are hypervascular.  contrast enhancement is usually

strong and heterogeneous due to areas or hemorrhage and necrosis

2. If CT inconclusive, get a Ultrasound to differentiate solid vs. cystic *** Most commonly is hyperechoic on sonography, but can also be

hypo- and isoechoic

3. If still nondiagnostic or if pt can’t receive IV contrast, consider MRI

4. When working up pt for possible metastasis, bone scans and PET scans are effective (however bone scan are only recommended for

pts with bone pain or elevated serum alkaline phosphatase).

Discussion

Staging: Robson StagingStage 1 - Confined to the kidney Stage 2 - Involvement of perinephric fat but Gerota's fascia intact Stage 3 - Spread into renal vein Stage 4 - Spread into adjacent or distant organs

I >90%, II 75-90%, III 50-70%, IV <10%

Metastasize most commonly to these locations: lung, lymph nodes, bone, liver, brain, and ipsilateral adrenal gland. ***Greatest risk for recurrence is within 5 years, approximately 10% of pts present w/ metastasis 5 years post nephrectomy.

Although recurrence of RCC has a poor prognosis, some studies are show longer survival w/ increased interval between nephrectomy and recurrence and also single foci of metastasis.

Decreased survival is shown w/ serum LDH >1.5 normal, serum Ca >10mg/dl, hemoglobin concentrations below normal, absence of disease free interval.

Discussion

Lung Mets: 29-54% of pts w/ recurrence, 90% diagnosed without symptoms, however f/u w/ CT vs CXR is still debated.

Bone Mets: 16-31% of pts w/ recurrence, however 67-91% do present w/ localized pain. Usually only monitored by symptoms

and serum alkaline phosphatase levels.

Liver Mets: 8-30% of pts w/ recurrence, 90% or more are detected by symptoms or abnormal lab values.

Brain Mets: 2-10% of pts w/ recurrence, greater than 80% have symptoms, including; headaches, altered behavior, seizures or focal neurological signs.

Discussion

Renal Cell Carcinoma w/ distant metastases to bone, lung and adrenal gland.

Diagnosis

1.) Andreoli. Cecil Essentials of Medicine, 6th Ed., 2004.

2.) Atkins, Michael. Up To Date; Epidemiology, pathology, and pathogenesis of renal cell carcinoma, 2007.

3.) Peh, Wilfred. eMedicine; Bone Metastasis, 2007.

4.) Noveline, Robert A. Squire’s Fundamentals of Radiology, 6th Ed., 2004.

References