Undervalued and Underused

Fine needle aspiration (FNA) biopsy should be used to greater advantage for diagnosis and management of patients. Currently, many pathologists use it to document recurrent disease in a patient with known cancer, and others use it to drain cystic lesions. But due to a lack of training for pathologists in FNA cytology, many clinicians are actually unaware of the diagnostic power of FNA biopsy; many see excisional biopsy or core needle biopsy as the biopsy procedure of choice, because, historically, tissue is king. Consequently, surgeons will receive requests to obtain large tissue biopsies at the expense of the patient, both financially and in terms of morbidity.

Medicine has entered a new era, though, because of the revolutionary progress in human genomics. And as a result, molecular techniques are being used to diagnose, treat, and monitor treatment response and disease progression of an ever-increasing number of diseases. In my opinion, FNA biopsy is extremely well suited to procuring samples for molecular studies and deserves consideration as a first-line technique whenever possible. My reasons? Cells obtained by FNA are ideal for a multitude of ancillary studies and they may be superior to tissue biopsy specimens for such diagnostic tests. Indeed, more use of FNA biopsy during initial workup of mass lesions could reduce patient time and medical costs, and improve post-biopsy recuperation. And this would be accomplished without jeopardizing care!

Cytology specimens can be used for immunohistochemical (IHC) stains, flow cytometry, fluorescence in situ hybridization (FISH) and molecular tests for biochemical and genetic defects. For example, let’s say a patient has an enlarged supraclavicular lymph node. In such a case, FNA yields cells compatible with adenocarcinoma, and IHC stains are most consistent with a lung primary. Molecular studies are performed on the sample and, based on the molecular results, the patient proceeds directly to oncology for treatment. Another scenario could be a patient with an enlarged cervical lymph node demonstrating squamous cell carcinoma on aspiration biopsy. A needle rinse specimen can be tested for high-risk human papilloma virus (HPV) subtypes and therapy instituted on the cytology results. All of this information is obtainable using a narrow gauge needle with a simple, non-invasive, economical, quick outpatient clinic procedure.

Current practice for FNA biopsy in many centers is to obtain the specimen in the radiology department and then send it to pathology. Under this paradigm, though, there is no indication if a specimen contains the requisite number of cells to qualify as an adequate specimen until after the patient has left the clinic. If the biopsy cellularity is insufficient for diagnostic evaluation, or if the pathologist needs additional specimen for ancillary testing, the patient must return for a second biopsy. This is not an effective use of medical resources or the patient’s time. Additionally, some practices require the availability of a pathologist or cytotechnologist when the biopsy is done for “rapid on site evaluation” (ROSE) for specimen adequacy. ROSE is effective for obtaining a satisfactory sample but has limitations; it is time-intensive for pathology and reimbursement is low. Also, unless a pathologist is available, immediate decisions about triaging the specimen for studies such as flow cytometry, cultures, or molecular studies, are hindered.

A partial solution to the above problem is training pathologists in ultrasound guided FNA (USFNA) cytology. Pathologists with good hand-eye coordination can learn the USFNA technique reasonably quickly and this skill is immensely useful for any pathologist performing FNA biopsies. Ultrasound guidance allows for selective sampling of masses, which can sometimes make the difference between an adequate and inadequate sample. Ultrasound also gives the pathologist useful information about the lesion sampled such as shape, size, echogenic pattern and blood flow; this information can be integrated with the cytologic findings to render a more precise diagnosis or give guidance for follow-up care. USFNA by cytopathologists of superficial body sites including thyroid, superficial lymph nodes, salivary glands, breast and soft tissue, is within our scope of practice.

For those cytopathologists interested in optimizing FNA biopsy, particularly in this era of personalized medicine, I encourage them to explore the realm of USFNA. Not only will there be fewer specimens of insufficient cellularity for diagnosis with the technique, but patients will also benefit from the most appropriate testing on their FNA specimen.