Ultra Sound (USG): FNAC (Procedure) at Chughtai Lab

Introduction to Ultrasound-Guided Fine Needle Aspiration Cytology (USG-FNAC)

Ultrasound-Guided Fine Needle Aspiration Cytology (USG-FNAC) is a highly specialized, minimally invasive diagnostic procedure that bridges the gap between medical imaging and pathology. By combining the real-time visualization capabilities of high-resolution ultrasound with the precise cellular analysis of cytopathology, USG-FNAC allows clinicians to evaluate suspicious nodules, masses, and fluid collections with exceptional accuracy. This procedure is commonly performed on superficial structures of the body, such as the thyroid gland, lymph nodes, salivary glands, breast tissue, and other soft tissue masses. At Chughtai Lab, this procedure is executed by experienced consultant radiologists and pathologists using state-of-the-art diagnostic equipment, ensuring the highest standards of clinical safety and diagnostic yield.

The primary clinical value of USG-FNAC lies in its ability to differentiate between benign and malignant lesions without the need for an open surgical biopsy. During the procedure, high-frequency sound waves are utilized to generate real-time images of the target lesion. This continuous visual feedback allows the radiologist to guide an extremely thin, fine-gauge needle directly into the center of the mass, avoiding adjacent vital structures such as major blood vessels, nerves, and muscles. Once the needle is precisely positioned, microscopic cellular samples are aspirated and immediately prepared on glass slides for cytological examination. This integrated approach significantly reduces the rate of non-diagnostic or inadequate samples, providing patients and referring physicians with rapid, reliable, and actionable diagnostic insights.

Clinical Procedure: What to Expect

Patient Preparation

Proper preparation is essential to ensure patient safety and optimize the diagnostic quality of the aspirated sample. Patients scheduled for a USG-FNAC at Chughtai Lab should follow these clinical guidelines:

• Medication Review: Patients must inform their physician and the clinical staff at Chughtai Lab of all current medications. Antiplatelet agents (such as aspirin or clopidogrel) and anticoagulants (such as warfarin or novel oral anticoagulants) may need to be temporarily discontinued prior to the procedure to minimize the risk of hematoma formation. This must only be done under the direct supervision of the prescribing physician.
• Fasting Requirements: For standard superficial USG-FNAC (such as thyroid, lymph node, or breast), fasting is generally not required. Patients may eat a light meal and drink fluids normally before their appointment.
• Hygiene and Clothing: Patients should bathe or shower before the procedure. It is recommended to wear loose, comfortable clothing. For neck procedures (thyroid or cervical lymph nodes), patients should wear a collarless shirt and avoid wearing necklaces, chains, or other neck jewelry.
• Medical Records: Patients must bring all previous imaging reports, including prior ultrasound scans, CT scans, MRI reports, and relevant blood test results (such as thyroid function tests or coagulation profiles) to assist the radiologist in targeting the correct lesion.
• Allergy Notification: Any known allergies to local anesthetics, antiseptic solutions (like iodine or chlorhexidine), or latex must be communicated to the clinical team before the procedure begins.

During the Procedure

The USG-FNAC procedure is performed in a dedicated, sterile diagnostic suite at Chughtai Lab. The step-by-step process is designed to maximize patient comfort and diagnostic accuracy:

• Patient Positioning: The patient is positioned comfortably on an examination table. For a neck or thyroid FNAC, the patient lies flat on their back (supine) with a pillow placed under the shoulders to gently extend the neck, exposing the target area.
• Aseptic Technique: The radiologist identifies the target nodule using a high-frequency linear ultrasound probe. The skin overlying the target area is then thoroughly cleansed with a medical-grade antiseptic solution to establish a sterile field.
• Anesthesia: In many cases, because the needle used for FNAC is extremely thin (often thinner than the needle used for a routine blood test), local anesthesia is not required, as the anesthetic injection itself can cause similar or greater discomfort. However, depending on the location of the lesion and patient preference, a small amount of local anesthetic may be administered to numb the skin.
• Ultrasound Guidance and Aspiration: Under continuous, real-time ultrasound visualization, the radiologist gently inserts the fine needle through the skin and guides it directly into the lesion. Once the needle tip is confirmed to be within the target mass, gentle suction is applied, or capillary action is utilized, to draw microscopic cellular material into the needle. The needle may be moved slightly within the lesion (fanning technique) to collect a representative sample.
• Sample Processing: The needle is withdrawn, and pressure is immediately applied to the puncture site to prevent bleeding. The collected cellular material is immediately expressed onto glass slides. These slides are either air-dried or fixed in an alcohol solution for subsequent staining and evaluation by a consultant pathologist.
• Duration and Post-Procedure Care: The entire procedure, including ultrasound localization and sample collection, typically takes between 15 to 30 minutes. After a brief period of observation, a small adhesive bandage is applied to the site, and the patient is cleared to return to their normal daily activities.

When is a USG FNAC Performed?

Evaluation of Suspicious Thyroid Nodules

Thyroid nodules are highly prevalent in the general population. While the majority are benign, USG-FNAC is indicated when an ultrasound scan reveals suspicious sonographic features. These features include microcalcifications, irregular margins, marked hypoechogenicity, a shape that is taller than it is wide, or rapid nodular growth. Physicians request USG-FNAC to rule out thyroid malignancies, such as papillary, follicular, medullary, or anaplastic thyroid carcinoma, allowing for timely surgical planning or reassurance.

Investigation of Persistent Lymphadenopathy

Enlarged lymph nodes in the neck (cervical), armpits (axillary), or groin (inguinal) that persist for several weeks without an obvious infectious cause require diagnostic evaluation. USG-FNAC is performed to differentiate between reactive lymphadenitis (secondary to infection or inflammation), lymphoma (primary lymphatic malignancy), and metastatic disease (cancer spreading from another primary site). The real-time ultrasound guidance ensures that the needle targets the most abnormal-looking portion of the lymph node, such as areas with loss of normal fatty hilum or abnormal vascularity.

Assessment of Salivary Gland Masses

Tumors or inflammatory masses in the parotid, submandibular, or sublingual salivary glands can present as painless, slowly growing swellings. USG-FNAC is requested to characterize these masses before surgical intervention. It helps distinguish benign salivary gland neoplasms, such as pleomorphic adenoma or Warthin’s tumor, from malignant conditions like mucoepidermoid carcinoma or adenoid cystic carcinoma, which require distinct surgical and therapeutic approaches.

Characterization of Palpable Breast Lumps

When a patient or clinician detects a palpable breast lump, or when a screening mammogram reveals an indeterminate lesion (often classified under BI-RADS categories), USG-FNAC may be indicated. It is particularly useful for distinguishing solid masses from complex, thick-walled fluid cysts. If the lesion is solid, FNAC provides a rapid cytological diagnosis, helping to differentiate benign fibroadenomas or fibrocystic changes from breast carcinomas.

Diagnostic Workup for Soft Tissue Masses

Unexplained lumps or swellings in the subcutaneous tissues, muscles, or deep soft tissues of the body can be evaluated using USG-FNAC. This includes the assessment of suspected lipomas, epidermal inclusion cysts, ganglion cysts, or inflammatory abscesses. By obtaining a cellular sample, clinicians can confirm the benign nature of these soft tissue lesions or identify atypical spindle cell proliferations that may warrant a more extensive core needle biopsy or surgical excision.

What Does a USG FNAC Detect?

USG-FNAC is capable of detecting a wide array of benign, inflammatory, infectious, and malignant conditions across various anatomical sites. Some of the key diagnostic findings include:

• Colloid Nodule: A benign thyroid condition characterized by abundant colloid material and normal follicular cells.
• Hashimoto’s Thyroiditis: An autoimmune thyroid disease showing a background of numerous lymphocytes and Hurthle cells.
• Papillary Thyroid Carcinoma: The most common thyroid malignancy, characterized by papillary clusters, intranuclear inclusions, and nuclear grooves.
• Follicular Neoplasm: An indeterminate thyroid lesion showing highly cellular smears with microfollicular patterns, requiring surgical excision for definitive diagnosis.
• Medullary Thyroid Carcinoma: A neuroendocrine tumor of the thyroid showing plasmacytoid or spindle-shaped cells that stain positive for calcitonin.
• Anaplastic Thyroid Carcinoma: A highly aggressive thyroid malignancy presenting with highly atypical, pleomorphic giant cells and necrotic debris.
• Reactive Lymphadenitis: A benign, self-limiting enlargement of lymph nodes showing a polymorphous population of lymphoid cells.
• Tuberculous Lymphadenitis: An infectious condition characterized by necrotizing granulomatous inflammation, Langhans giant cells, and acid-fast bacilli.
• Metastatic Squamous Cell Carcinoma: Malignant epithelial cells found within a lymph node, indicating spread from a primary head and neck cancer.
• Metastatic Adenocarcinoma: Glandular malignant cells in a lymph node, indicating metastasis from primary sites like the breast, lung, or gastrointestinal tract.
• Hodgkin Lymphoma: A primary lymphatic malignancy characterized by the presence of diagnostic Reed-Sternberg cells in a reactive background.
• Non-Hodgkin Lymphoma: A clonal proliferation of atypical lymphocytes, which may require flow cytometry for definitive subtyping.
• Pleomorphic Adenoma: The most common benign salivary gland tumor, showing a mixture of epithelial elements and myxoid or chondromyxoid stroma.
• Warthin’s Tumor: A benign salivary gland lesion characterized by bilayered oncocytes and a lymphoid stroma.
• Mucoepidermoid Carcinoma: A malignant salivary gland tumor containing mucinous, intermediate, and squamous cells.
• Adenoid Cystic Carcinoma: A malignant salivary gland tumor showing characteristic cribriform clusters of basaloid cells with hyaline globules.
• Fibroadenoma: A benign breast lesion characterized by cohesive, staghorn-like sheets of benign ductal epithelial cells.
• Invasive Ductal Carcinoma: The most common malignant breast tumor, showing highly atypical, discohesive epithelial cells with prominent nucleoli.
• Epidermal Inclusion Cyst: A benign soft tissue lesion containing abundant anucleated squamous cells and keratin debris.
• Lipoma: A benign soft tissue tumor composed of mature, uniform adipocytes without atypia.
• Acute Suppurative Inflammation: An infectious process characterized by dense sheets of neutrophils and necrotic cellular debris, indicative of an abscess.
• Granulomatous Mastitis: An inflammatory breast condition showing epithelioid histiocytes, giant cells, and neutrophilic microabscesses.
• Branchial Cleft Cyst: A congenital neck cyst containing benign squamous or columnar cells and cholesterol crystals.
• Thyroglossal Duct Cyst: A midline neck cyst containing mucoid material, ciliated columnar cells, and occasional thyroid follicular cells.
• Fat Necrosis: A benign inflammatory reaction in the breast or soft tissue showing lipid-laden macrophages and multinucleated giant cells.

Turnaround Time and Report Access at Chughtai Lab

At Chughtai Lab, we understand that waiting for diagnostic results can be an anxious time for patients and their families. Therefore, we have optimized our cytopathology workflow to ensure both speed and accuracy. Once the USG-FNAC sample is collected, the slides are immediately transferred to our central pathology laboratory. Here, they undergo specialized staining (such as H&E, Diff-Quik, or Papanicolaou stains) and are meticulously analyzed by our board-certified consultant pathologists.

The standard turnaround time for a USG-FNAC report at Chughtai Lab is typically 24 to 48 hours, depending on whether special stains or immunohistochemical markers are required for a definitive diagnosis. Once the report is finalized and signed off by the consultant pathologist, patients receive an automated SMS notification. Reports can be easily accessed, viewed, and downloaded online via the official Chughtai Lab patient portal or mobile application. Physical copies of the reports can also be collected from any Chughtai Lab diagnostic center across Pakistan, including major hubs in Lahore, Karachi, Islamabad, Peshawar, and Multan.

USG FNAC Findings Overview

Structure / Parameter Evaluated	Normal Findings	Possible Abnormal Findings
Thyroid Gland	Abundant colloid, cohesive sheets of uniform follicular cells, no nuclear atypia.	Microfollicular arrangement, nuclear grooves, intranuclear inclusions, psammoma bodies (suggestive of malignancy).
Lymph Nodes	Polymorphous population of lymphocytes, tingible body macrophages, intact nodal architecture.	Monomorphous lymphoid population (lymphoma), metastatic epithelial cells, caseating granulomas (tuberculosis).
Salivary Glands	Normal acinar cells, ductal epithelial cells, background of thin saliva.	Myxoid stroma with spindle cells (pleomorphic adenoma), atypical squamous and mucinous cells (mucoepidermoid carcinoma).
Breast Tissue	Cohesive sheets of benign ductal cells, bipolar naked nuclei, clean background.	Highly atypical, discohesive epithelial cells, necrotic background, prominent nucleoli (breast carcinoma).
Soft Tissue Masses	Mature adipocytes, fibrous tissue fragments, or clear cystic fluid.	Atypical spindle cells, pleomorphic lipoblasts, abundant neutrophils, and necrotic debris (sarcoma or abscess).
Cellular Adequacy	Sufficient diagnostic cellular material present on multiple slides.	Acellular smear, blood-only sample, or excessive drying artifact rendering the sample non-diagnostic.
Background Elements	Clean background, minimal red blood cells, normal physiological secretions.	Necrotic debris, proteinaceous fluid, calcifications, acute inflammatory exudate, or foreign body giant cells.

Note: Diagnostic findings should always be interpreted by a qualified healthcare professional together with the patient’s symptoms, medical history, physical examination, laboratory investigations, previous imaging studies, and other relevant clinical information. Additional investigations or specialist consultation may be recommended depending on the findings.

Why Choose Chughtai Lab for USG FNAC?

• Experienced Healthcare Professionals: Our USG-FNAC procedures are performed by highly skilled consultant radiologists and pathologists who specialize in interventional diagnostics.
• High-Resolution Ultrasound Guidance: We utilize advanced, state-of-the-art ultrasound machines to ensure precise needle placement and maximum diagnostic yield.
• State-of-the-Art Cytopathology Lab: Samples are processed and analyzed in our fully equipped pathology laboratories using international standard staining techniques.
• Rapid Turnaround Time: We prioritize cytopathology reporting to deliver accurate results within 24 to 48 hours, minimizing patient anxiety.
• Convenient Online Report Access: Patient reports are accessible 24/7 through our secure online portal, mobile app, and via SMS alerts.
• Strict Quality Control: Chughtai Lab adheres to rigorous internal and external quality assurance protocols, ensuring international standards of diagnostic accuracy.
• Widespread Network: With diagnostic centers located across all major cities in Pakistan, patients can easily access our services close to home.
• Patient-Focused Care: We provide a compassionate, safe, and comfortable environment, ensuring that patients are well-informed and supported throughout the procedure.