1. Consultation—Is a percutaneous biopsy indicated? Are special preparation steps needed? Evaluate medical record; review pertinent imaging examinations
to establish indication and determine feasibility. Establish consentability, determine need for anesthesiology; assess need for preprocedure laboratory tests.

a. Consider inpatient biopsies when

(1) Patient is in hospital for other reasons.

(2) Risk of biopsy is increased (e.g., medical comorbidities, lesion type, and location).

(3) Patient lives alone or far away.

2. Preprocedure patient preparation: Deliver preparation instructions to patient. Withhold solid food (except medications) for 6 hours and clear liquids for 3 hours when minimal or moderate sedation (formerly known as conscious sedation) is planned. Withhold solid food for 8 hours when deep sedation or general anaesthesia is planned; both require presence of an anesthesiologist.

a. Instruct patient to arrive 1 hour prior to procedure.

b. Ask patient to arrange for a responsible adult companion to provide transport to home, and, if possible, someone to accompany overnight.

c. Advise patient of possible signs and symptoms of complications and provide contact information.

d. Discontinue medications that affect hemostasis (3,4,5) (e.g., heparin, warfarin, aspirin, clopidogrel). Discuss risks of discontinuing medications (e.g., prior cerebrovascular event, myocardial infarction, or prior coronary stent placement) with care providers (e.g., a cardiology consult) before considering for biopsy.

e. Warfarin should be discontinued (typically 5 days); low-molecular-weight heparin (LMWH) bridge can be considered if high risk, for example, heart valve surgery, recent pulmonary embolism, and deep vein thrombosis.

f. Discontinue aspirin or clopidogrel for at least 5 days especially with high risk for bleeding. Other nonsteroidal anti-inflammatory drugs (NSAIDs) could be stopped for 48 hours. Restart aspirin, clopidogrel, or NSAIDs >12 hours after the procedure when low risk for bleeding and >24 hours when high risk for bleeding.

g. Heparin (unfractionated, intravenous [IV] or subcutaneous [SQ]): If prophylactic dose, discontinue for 4 to 6 hours, no need to recheck partial thromboplastin time (PTT); restart >12 hours when low risk for bleeding and >24 hours when high risk for bleeding. If therapeutic dose, discontinue for 4 to 6 hours, recheck PTT; restart >12 hours when low risk for bleeding and >24 hours when high risk for bleeding. For patients on LMWH, prophylactic dose (5,000 IU once per day) stop 12 hours before and therapeutic dose (≥5,000 IU once per day) stop 24 hours before the procedure. Restart prophylactic and therapeutic dose >12 hours after the procedure when low risk of bleeding >24 hours when high risk for bleeding.

3. Day of procedure: Obtain written informed consent. Detail indications as they relate to the patient’s medical problem, the benefits, risks (including specific potential complications, their probability of occurrence, and steps to minimize their risk), alternative procedures, and other relevant aspects of the procedure (e.g., the planned approach and how long the procedure will take). Give patient specific instructions on how to cooperate during the biopsy (e.g., breath holding).

4. Laboratory tests

a. Obtain serum prothrombin time (PT) (international normalized ratio [INR]) and complete blood count (CBC) if normal values have not been documented in the medical record in the prior 30 days. If normal values have been documented, these tests do not need to be repeated unless there are risk factors for bleeding such as medications that could alter coagulation, diseases known to alter hemostasis (e.g., liver disease), or other reasons to suspect a bleeding diathesis. Obtain serum PTT only if a normal documented value has not been documented in the past. PTT does not need to be remeasured unless there are new risk factors such as medications, diseases, or other reasons to suspect an alteration in PTT.
General guidelines for hemostatic parameters include PT <15 seconds, INR <1.5, PTT <1.5 × control, and platelet count >50,000 per µL; however, deviation from these guidelines can be considered if clinically indicated.

b. Adrenal mass biopsy: If pheochromocytoma (6) is a consideration, measure plasma-free fractionated metanephrines (high sensitivity especially in patients with hereditary predisposition to pheochromocytoma, but false positives possible especially in sporadic cases), and if positive, the specificity can be increased by 24-hour measurement of urine-fractionated metanephrines and catecholamines.

c. Liver cyst aspiration: Consider echinococcal serology in suspected cases.

5. Arrange for “on-site” cytopathologist for preliminary reading of cytology; this has several advantages (7).

a. Offers immediate assessment of adequacy of specimen and improves yield

b. Allows for altering approach or technique if preliminary tissue specimen is insufficient

c. Allows selective processing of specimen for special studies (e.g., culture if material suggests infection, marker studies for lymphoma, electron microscopy, cytogenetics for some tumors, and measurement of tumor-specific markers).

d. Limits the number of passes to no more than what is necessary, particularly in high-risk procedures.

6. Choose an image-guidance system (1,8).

a. Fluoroscopy—utilization for image-guided biopsy is largely obsolete except for transjugular liver parenchymal biopsy.

b. Ultrasound (US)

(1) Advantages: rapid localization, real-time and multiplanar, flexible patient positioning, no ionizing radiation, Doppler can reveal vascularity

(2) Disadvantages: Deeply located lesions, especially those that are small, may not be visible due to intervening structures such as bowel.

c. Computed tomography (CT)

(1) Advantages: helps visualize deep small lesions, depicts tissue components, vascularity, precise anatomic relationships (e.g., bowel and pleural space), precise needle localization possible, multiplanar guidance possible with reconstructions. CT fluoroscopy with either intermittent “quick check” scans or continuous, near real-time scans can shorten needle placement time.

(2) Disadvantages: ionizing radiation, more expensive, and time-consuming compared to US

d. Magnetic resonance imaging (MRI)

(1) Advantages: useful for lesions seen on MRI alone, multiplanar, no ionizing radiation

(2) Disadvantages: expensive, limited availability, MRI-compatible equipment required