Review Question - QID 3806

In patients with multiple spinal metastases on their initial presentation and a high index of suspicion for a primary source (elevated PSA pointing to prostate cancer), staging and diagnostic studies can be ordered together since they are necessary to establish a diagnosis and to initiate treatment. Of the listed choices, a bone marrow biopsy would NOT be a part of the initial workup since prostate cancer rarely metastasizes to the bone marrow.

Spinal metastases are the first sign of malignancy in 20% of patients with metastatic disease of the spine. The most common cancers that metastasize to bones are thyroid, lung, breast, kidney, and prostate A diagnostic algorithm that includes history, physical examination, plain radiography, laboratory testing, bone scintigraphy, and CT scanning will identify the primary tumor in 85% of cases of spinal metastasis. A biopsy will identify another 8% and can be of the likely primary source or an area of suspected metastasis.

Rose and Buchowski review the evaluation and management of spinal metastatic disease. They stress that both diagnostic and treatment strategies must be individualized to patients. Three specific categories of patients present with spinal metastasis: (1) patients with known metastatic disease, (2) patients with known malignancy but without a history of metastatic disease, and (3) patients with no prior history of malignancy. Patients in categories (2) and (3) require further evaluation prior to treatment.

Rougraff discusses the evaluation of a patient presenting with carcinoma of unknown origin with bony metastases. The author emphasizes the importance of combining the history, clinical exam, laboratory and radiographic studies in order to diagnose the primary malignancy and that biopsy is most effective as a confirmatory test.

Incorrect Answers:
Answer 1: Given the significant elevation of PSA, a prostate biopsy may be a part of the initial workup to establish a diagnosis.
Answer 2: CT of the chest/abdomen/pelvis is required for the appropriate staging of metastatic disease and should be included in the initial workup.
Answers 4: A whole-body bone scan should be a part of the initial workup of a patient with spinal metastatic disease to further determine the extent of metastasis.
Answer 5: A CT-guided biopsy of a metastatic spine lesion is a reasonable part of the initial workup since these lesions can be easier to biopsy than visceral lesions in liver/lung/nodal metastasis that may be discovered on a CT scan.