World Health Organization classification of tumours: pathology and genetics of head and neck tumours.

Over the past decade working as a consultant head and neck pathologist, I have come to realize the importance of nomenclature and terminology in the diagnosis of head and neck organ diseases. There have been many cases in which the pathologist has had the right diagnosis but has used a term that is unfamiliar to the primary care physician, surgeon, oncologist, radiation therapist, or geneticist, resulting in confusion and unnecessary delay in treatment.

Classification schemes are used to provide a foundation for tumor diagnosis with a reproducible approach to terminology, which aids the clinician in planning treatment, gives an indication of prognosis, allows for an evaluation of the treatment results, and facilitates the easy exchange of information between the ever-expanding number of physicians and healthcare providers involved in treating patients effectively. Frequently, patients are referred for outside opinions or to a tertiary medical center for treatment. Utilization of similar terminology by each of the facilities streamlines the patient's treatment.

The World Health Organization (WHO) has been at the forefront of tumor classification since it began the first International Histological Classification of Tumours series back in 1967. The first book devoted to head and neck tumors, published in 1971, was on the histologic typing of oropharyngeal tumors. It included 40 color plates and was published in multiple languages, at a cost of $4. Contributing pathologists were from 11 countries. Thirty-four years later, with a number of iterations between, the WHO has just (September 2005) published a new volume on the histologic and genetic typing of tumors, Pathology and Genetics of Head and Neck Tumours. Prepared by 130 authors from 28 countries, this authoritative and concise volume provides an international standard reference book on tumors of the head and neck. The diagnostic criteria, pathologic features, and associated genetic alterations were developed further by convening a Working Group of more than 35 highly respected authorities from multiple disciplines in medicine at an Editorial and Consensus Conference. They carefully adjusted and clarified the exact terms to be included.

The 430-page book covers tumors of the nasal cavity and paranasal sinuses, nasopharynx, hypopharynx, larynx and trachea, oral cavity and oropharynx, salivary glands, gnathic and odontogenic regions, ear and temporal bone, and the paraganglionic system. Each neoplasm is presented in a highly templated style, including definition, epidemiology, etiology, localization, clinical features, radiographic findings, tumor spread and staging, macroscopy, histopathology, ancillary studies (histochemical, immunohistochemical, ultrastructural, molecular, and genetic), differential diagnosis, precursor lesions, histogenesis, and prognosis and predictive factors, including methods of treatment. All of these data are richly illustrated with 890 color photographs, radiographic studies, and charts, and are supported by more than 2,900 pertinent references. All of this appears in a handy 8.5 x 11" format for $110.

As a pathologist, I find this book to be essential in guiding my use of diagnostic terminology that is easily understood, readily referenced, and clinically relevant in the care of patients with head and neck tumors. The information it contains is invaluable to otolaryngologists, especially as an adjunct to the 6th edition of the TNM Classification of Malignant Tumors from the International Union Against Cancer. Maintaining awareness of the latest trends in nomenclature, and striving for consistency and precision in terminology, should help all of us optimize our abilities to care for patients with head and neck disease, and to interpret our literature and assess our outcomes.

Suggested reading

Barnes L, Eveson JW, Reichart P, Sidransky D, eds. Pathology and Genetics of Head and Neck Tumours. Kleihues R Sobin LH, series eds. World Health Organization Classification of Tumours. Lyon, France: IARC Press, 2005 (Paperback, ISBN:9283224175, $110, www.iarc.fr).

International Union Against Cancer (UICC): TNM Classification of Malignant Tumors, 6th ed. Sobin LH, Wittekind CH, eds. New York: John Wiley & Sons, 2002.

LESTER D.R. THOMPSON, MD, FASCP 

Southern California Permanente Medical Group

Woodland Hills Medical Center

Department of Pathology

Woodland Hills, California