Nasal cytology: An untapped diagnostic tool

Although the diagnostic value of nasal cytology has long been established, widespread systematic implementation of this very simple, quick, and safe procedure in the pediatric population is still lacking. A recent review paper evaluating the advantages of using the nasal cytology procedure in the pediatric population¹ once again reinforced the clinical importance of nasal cytology as an adjunct diagnostic tool, and underscores its great utility in the optimization of the treatment and management of nasal disorders in the pediatric population.

Matteo Gelardi, MD“Contrary to all the cytologic procedures performed in other parts of the human body such as the thyroid, breast, salivary glands, and lymph nodes, nasal cytology is not an invasive procedure and does not require any anesthesia. The technique does not require a histological sample but instead only a simple surface cytological collection performed with a little spoon (Rhino-probe) or a tampon (similar to the oropharyngeal tampon), which is inserted in the corresponding inferior turbinate. As the procedure is painless, quick, and safe, it can be viewed as an ideal adjunct diagnostic procedure to further help in the treatment and management of patients with nasal disorders,” says Matteo Gelardi, MD, Section of Otolaryngology, Department of Basic Medical Science, Neuroscience and Sensory Organs, University of Bari, Italy.

Nasal cytology has been proven time and again to be a very useful diagnostic procedure for nasal disorders and diseases, being able to detect both the cellular modifications of the nasal epithelium caused by allergen exposure, irritative stimuli (physical or chemical), or inflammation. In addition to elucidating the fine differences and nuances among newly identified disorders including nonallergic rhinitis with eosinophils (NARES), nonallergic rhinitis with mast cells (NARMA), and nonallergic rhinitis with neutrophils (NARESMA), Gelardi says that the technique also can help to distinguish between the different forms of allergic rhinitis, thereby assisting clinicians to more quickly home in on an appropriate therapy, whether anti-inflammatory agents or allergen immunotherapy.

Several different diagnostic tests are currently being used in the field of otolaryngology, including macroscopic (nasal endoscopy), microscopic (nasal cytology), allergological (prick test), and functional tests (rhinomanometry), and each procedure opens up a diagnostic window that gives clinicians a better overall picture of the disease under investigation. Unfortunately, however, Gelardi says that nasal cytology still isn’t being used enough in the pediatric field or in other specialties. Historically, one of the main reasons is suspected to be the lack of standardization of the cytological procedures related to the sampling and interpreting of nasal cytograms. Gelardi says that the literature created over the last years has been very specific in helping to put these issues to rest, opening the door for a newly found trust and reliance in the procedure. Gelardi also recently published a theoretical aid to help further clarify all the cytomorphological aspects of the normal and pathologic nasal mucosa.²

Children are frequently affected by nasal pathologies, particularly during the early childhood period in which infectious diseases and allergies are generally overlapped. As such, Gelardi says that nasal cytology can be very useful in differentiating among these diseases, allowing clinicians to initiate an appropriate and exacted therapy. For instance, the cytology of bacterial rhinitis is microscopically characterized by the presence of numerous bacteria and neutrophils, and traces of biofilm often can be observed in the cytogram as an expression of the chronicity of the existing rhinopathy. In acute allergic diseases, the cytogram is always characterized by the presence of partially degranulated eosinophils and mast cells. Such “characteristic” cytograms can quickly help clinicians classify the disease in question and commence with appropriate therapy.

After performing the cytogram, the clinical and therapeutic follow-up plays an important role, Gelardi says, because it allows the physician to personalize the treatment according to the cytological representation of the individual patient (ie, bacteria persistence, presence of biofilm, as well as status of the eosinophils and mast cells degranulation).

“Nasal cytology turns indispensable when the presence of an allergic rhinitis is suspected, even if all of the tests previously performed (ie, prick test, [radioallergosorbent test], etc) demonstrated negative results. In these cases, in fact, nasal cytology is the only diagnostic tool able to identify those rhinopathies usually defined as vasomotor, nonspecific, idiopathic, or cryptogenic. Fortunately, there is a growing interest for pediatricians, allergists, and [ear, nose, and throat] specialists to develop the skills to perform standardized nasal cytology exams in their patients, a trend that we hope will continue for the benefit of our patients,” Gelardi says.

References

1. Gelardi M, Iannuzzi L, Quaranta N, Landi M, Passalacqua G. Nasal cytology: practical aspects and clinical relevance. Clin Exp Allergy. March 24, 2016. Epub ahead of print.

2. Gelardi M. Atlas of Nasal Cytology for the Differential Diagnosis of Nasal Diseases. 2nd ed. Milan, Italy: Edi-ermes; 2012.