How a Biopsy Works — From Sample Collection to Final Diagnosis
The Investigation That Provides the Definitive Answer
When a doctor recommends a biopsy, patients often feel a surge of anxiety — not necessarily because of what the word implies, but because of uncertainty about what the procedure actually involves. Will it hurt? How long will it take? When will the results come? What will happen next? These are entirely reasonable questions, and clear answers to them transform a frightening unknown into a manageable, well-understood clinical process.
A biopsy is the removal of a small sample of tissue from the body for laboratory examination. It is the investigation that provides the most definitive answers in medicine — confirming or excluding cancer, identifying the specific type of disease affecting an organ, determining whether a condition is responding to treatment, and providing the biological information that guides every subsequent clinical decision. At Alnoor Diagnostic Centre in Shadman, Lahore, we perform biopsies under imaging guidance and provide the histopathological examination that transforms a tissue sample into a clinically actionable diagnosis.
Why a Biopsy Is Recommended
A biopsy is recommended when clinical examination, blood tests, and imaging have identified an abnormality but cannot provide the definitive diagnosis that treatment planning requires. An ultrasound may show a liver mass but cannot confirm whether it is a benign cyst, a haemangioma, a primary liver tumour, or a metastasis from another cancer. A mammogram may show a suspicious area in the breast but cannot determine whether it is benign fibrocystic change or malignant carcinoma. An enlarged lymph node may be reactive from infection or represent lymphoma — and only tissue examination distinguishes between them.
The biopsy provides the tissue that the pathologist examines under the microscope, where the cellular architecture reveals the diagnosis that no other investigation can provide with equivalent certainty.
Types of Biopsy — Matched to the Clinical Situation
Different biopsy techniques are used depending on where the target tissue is located, how accessible it is, and how much tissue is needed for adequate histopathological examination.
Core needle biopsy is the most commonly performed image-guided biopsy technique at Alnoor Diagnostic Centre. A hollow biopsy needle is advanced into the target lesion under real-time imaging guidance — ultrasound for superficial lesions in the breast, liver, lymph nodes, and soft tissue, or CT guidance for deeper lesions in the lung, retroperitoneum, and bone. The needle contains a spring-loaded cutting mechanism that fires rapidly to extract a cylindrical core of tissue — typically one to two centimetres long and one to two millimetres in diameter. Multiple cores are taken from different areas of the lesion to ensure representative sampling. The procedure takes fifteen to thirty minutes and is performed under local anaesthesia.
Fine needle aspiration cytology — FNAC uses a thinner needle attached to a syringe to aspirate cells — rather than a tissue core — from a lesion. The aspirated material is smeared onto glass slides and examined cytologically — individual cells and cell clusters are assessed rather than intact tissue architecture. FNAC is faster and less invasive than core needle biopsy but provides less tissue information. It is most appropriate for superficial lesions where cytological examination is sufficient for diagnosis — thyroid nodules, salivary gland lesions, and superficial lymph nodes are common FNAC targets.
Endoscopic biopsy is performed during gastroscopy, colonoscopy, bronchoscopy, or cystoscopy when mucosal abnormalities in the gastrointestinal, respiratory, or urological tracts require tissue sampling. Small biopsy forceps passed through the endoscope channel grasp and remove small mucosal fragments under direct visual guidance.
Surgical excision biopsy removes the entire lesion rather than a representative sample — serving as both diagnostic and therapeutic. This approach is used when the lesion is small enough for complete removal, when the tissue architecture of the whole lesion is needed for diagnosis, or when the lesion cannot be adequately sampled by needle techniques.
What Happens During an Image-Guided Core Needle Biopsy
Understanding the step-by-step process of a core needle biopsy removes the uncertainty that makes patients anxious before the procedure.
Arrival and preparation — When you arrive at Alnoor Diagnostic Centre, the team confirms your identity and reviews your clinical history, relevant imaging, and any blood tests including clotting function. You will be asked about any blood-thinning medications — anticoagulants must frequently be paused before biopsy, and your referring doctor will have provided specific instructions. An intravenous line may be placed if sedation is planned.
Positioning — You are positioned on the procedure table in the orientation that gives the radiologist optimal access to the target lesion while maintaining your comfort. For a breast biopsy you may lie on your back or side. For a liver or kidney biopsy you typically lie on your side or prone. The skin over the biopsy site is cleaned with antiseptic solution and sterile drapes are applied.
Imaging guidance and planning — The radiologist uses ultrasound or CT imaging to identify the target lesion and plan the needle path — selecting the approach that reaches the lesion most directly while avoiding critical structures including major blood vessels, bile ducts, and bowel.
Local anaesthesia — Local anaesthetic is injected into the skin and the deeper tissues along the planned needle path. This produces a brief stinging sensation that resolves within seconds. Once the anaesthetic has taken effect — typically two to three minutes — the deeper tissues are numb and the procedure itself causes no sharp pain. Patients may feel pressure as the needle is advanced, and a brief clicking sound and sensation when the biopsy device fires — but not pain.
Core sampling — The biopsy needle is advanced under continuous imaging guidance to the edge of the target lesion. The position is confirmed on imaging before the biopsy device is fired. The spring-loaded mechanism fires in a fraction of a second, cutting and capturing a core of tissue. The needle is withdrawn and the core sample is placed in formalin solution. Typically three to five cores are taken from different areas of the lesion to ensure comprehensive sampling. Each firing takes only a moment and the entire sampling phase lasts only a few minutes.
Post-procedure care — Firm pressure is applied to the biopsy site for several minutes to minimise bleeding. In most cases this is sufficient haemostasis. A small sterile dressing is applied. You are observed for fifteen to thirty minutes before discharge in most cases. Most patients feel comfortable enough to travel home independently for superficial biopsies, though having a companion is always advisable. Post-procedure instructions cover activity restrictions — typically avoiding strenuous activity for twenty-four to forty-eight hours — and describe the symptoms that would require urgent medical attention, including significant swelling, haemorrhage, fever, or severe pain.
What Happens to the Tissue Sample
The biopsy cores are transported to the histopathology laboratory immersed in formalin — the fixative that halts biological processes and preserves the tissue architecture at the cellular level. In the laboratory, the tissue undergoes the standardised processing sequence — fixation, embedding in paraffin wax, sectioning on a microtome, staining with haematoxylin and eosin, and any additional special stains or immunohistochemical studies indicated by the preliminary microscopic findings.
The pathologist examines the stained slides systematically — assessing tissue architecture, cellular characteristics, the nature of any inflammatory response, and any features of malignancy including abnormal nuclear morphology, increased mitotic activity, and invasion of surrounding structures. When additional immunohistochemical studies are needed — to determine the type of malignancy, identify specific markers that guide treatment, or confirm a specific diagnosis — additional sections from the paraffin block are stained with the appropriate antibodies. These studies add one to two days to the reporting timeline.
What the Biopsy Report Contains
The histopathology report provides the clinical team with the definitive tissue diagnosis. For a malignant lesion it specifies the tumour type and subtype, the grade reflecting cellular differentiation and aggressiveness, and the results of immunohistochemical studies that identify prognostic markers and treatment targets. For a benign lesion it provides a specific diagnosis — confirming whether the tissue is normal, shows reactive changes, inflammation, or a specific benign condition. For an inconclusive result it recommends the next diagnostic step.
The report is issued to the referring clinician who integrates the pathological diagnosis with the clinical and imaging findings to formulate the complete diagnosis and treatment plan. Most standard biopsies are reported within five to seven working days.
Image-Guided Biopsy and Histopathology at Alnoor Diagnostic Centre, Lahore
At Alnoor Diagnostic Centre in Shadman, Lahore, our interventional radiology team performs image-guided biopsies under ultrasound and CT guidance with the precision and patient care that this important procedure demands. Our histopathology laboratory provides expert tissue processing and pathological examination with the thoroughness and clinical relevance that every patient’s diagnosis deserves.