Skeletal Neoplasm Evaluation

Imaging Modalities

Various imaging techniques play crucial roles in identifying and characterizing skeletal neoplasms.

Radiography (X-ray)

Conventional radiographs are often the initial step, providing a broad overview of bone structure. They can reveal abnormalities such as lesions, fractures, or changes in bone density. Features observed on radiographs aid in differential diagnosis.

Computed Tomography (CT)

CT scanning provides cross-sectional images, allowing for detailed assessment of the bone and surrounding soft tissues. It is useful for evaluating the extent of a tumor, guiding biopsies, and assessing response to treatment.

Magnetic Resonance Imaging (MRI)

MRI offers superior soft tissue contrast, enabling detailed visualization of the tumor's relationship to nerves, blood vessels, and muscles. It is particularly useful for staging and surgical planning. Different MRI sequences (e.g., T1-weighted, T2-weighted, STIR) provide varying information about tissue characteristics.

Radionuclide Bone Scanning (Bone Scintigraphy)

Bone scans involve injecting a radioactive tracer that is absorbed by bone tissue. Areas of increased metabolic activity, such as tumors or fractures, will appear as "hot spots." It is helpful for detecting multiple lesions or metastases. SPECT/CT can provide more precise localization.

Positron Emission Tomography (PET) and PET/CT

PET scanning uses a radioactive tracer (typically FDG) to identify areas of high glucose metabolism, which is characteristic of many cancers. PET/CT combines PET with CT imaging, providing both functional and anatomical information. It is useful for staging, monitoring treatment response, and detecting recurrence.

Biopsy Procedures

A biopsy, the removal and examination of tissue under a microscope, is essential for confirming the diagnosis and determining the specific type of tumor.

Needle Biopsy

A needle is inserted into the bone to collect a small sample of tissue. Image guidance (CT or fluoroscopy) is often used to ensure accurate placement. Needle biopsies can be either core biopsies (removing a small cylinder of tissue) or fine-needle aspirations (collecting cells).

Incisional Biopsy

A surgical incision is made to remove a small piece of the tumor. This allows for a larger tissue sample to be obtained. The incision is typically placed in a way that will not compromise future surgical options.

Excisional Biopsy

The entire tumor is removed during the biopsy procedure. This is typically done when the tumor is small and easily accessible and suspicion of malignancy is low.

Pathological Evaluation

The tissue sample obtained during a biopsy is examined by a pathologist, who analyzes the cells under a microscope and performs special stains or molecular tests to identify the specific type of neoplasm. Factors evaluated include cell morphology, growth patterns, and presence of specific markers.

Laboratory Tests

Blood tests, such as alkaline phosphatase and lactate dehydrogenase (LDH), may be elevated in some individuals with aggressive skeletal neoplasms. These tests are not specific but can provide supporting information.