Fine Needle Aspiration Cytology (FNAC) is a minimally invasive and cost-effective generally outpatient based medical procedure/technique where a small (fine) needle is introduced into a suspicious lump, nodule or mass to obtain diagnostic material.
The diagnostic material is spread on glass slides that are then examined microscopically by the histopathologist, cytopathologist or a cytotechnologist.
The diagnostic accuracy of FNAC is 90-99% when performed in an appropriate setting.
The FNAC of a palpable mass/lesion is performed by histopathologists, cytopathologists and clinicians with a special expertise in both the aspiration technique and sample/specimen preparation.
This procedure is usually done at the FNAC clinic or the patient’s bedside which increases the diagnostic accuracy because the pathologists are able to make an on-site assessment of the specimen adequacy microscopically while the patient is still at the clinic.
If the specimen is insufficient then a respiration can be done. The pathologist may obtain additional specimen for special diagnostic studies that may refine the diagnosis.
The pathologist can contact the referring physician with a preliminary diagnosis within 1 hour.
The masses/lesions can be superficial or deep-seated. Superficial palpable masses/lesions are aspirated at the FNAC clinic are normally from the breasts, lymph nodes, head and neck, thyroid, salivary gland and other soft tissue masses.
FNAC of deep-seated masses/lesions is usually performed using radiographic image guidance (sonar guided FNAC).
The diagnostic accuracy of deep-seated masses/lesions increases when the radiologists and the pathologists work together.
Advantages of FNAC: It is safe, gives a rapid report, sensitive and specific for diagnosis of malignancy (cancer), benign (none cancer) and infective conditions, requires little equipment, cause minimal discomfort to the patient, is an out-patient procedure, reduces bed occupancy, allows preoperative diagnosis, reduces the incidence of exploratory procedures, allows a definitive diagnosis on inoperable patients and it is cost effective.
Disadvantages of FNAC: Aspiration technique requires practice and skills, certain percentage of the aspirates are unsatisfactory, interpretation requires experience and diagnostic material is limited.
Diagnostic accuracy of FNAC depends on several factors, including the site and type of the mass/lesion, experience of the aspirator, quality of the specimen preparation and diagnostic skills of the pathologist or the cytotechnologist.
Studies reported a greater accuracy in diagnosis when the same person performs the aspiration, prepares the smears, examines and give the diagnosis. This is achieved when there is a close cooperation between clinician and pathologists.
The Namibia Institute of Pathology (NIP) runs FNAC clinic every Thursday at Windhoek Central Hospital referral laboratory. Depending on clinical presentation of each and every patient we prepare samples for cytology, direct microscopy (DM) and TB-culture for suspected TB cases. Direct microscopy results are usually ready within 24 hours of sampling.
Requirements for the FNAC Clinic are a request form with a full clinical history and site to be aspirated, as well as a superficial 1 cm or more palpable and well defined mass/lesion. Patients must be stable and the request must include the name and contact details of the referring clinician
Most of the patients seen at our FNAC clinic are mainly from Windhoek and a few from Rehoboth. Upcountry patients are normally handled by their clinicians who then refer the aspirated material to Windhoek NIP for interpretation. Plans are underway for NIP to take FNAC services closer to the people in upcountry settings.
*Dr AM Iitana is an Anatomical Pathologist at the Namibia Institute of Pathology (NIP)
WINDHOEK DR AM IITANA