PATHOLOGY OF THE ORAL AND MAXILLOFACIAL REGION: DIAGNOSTIC AND SURGICAL CONSIDERATIONS

Surgical pathology is the specialty of medicine/dentistry that deals with the pathologic characteristics of tissue removed from the living patient. The tissue removed includes not only the solid tissue seen in biopsy material, but also the cells seen in smears, aspirates, and tissue cores. The surgical pathologist must be proficient in the evaluation of all types of cellular tissue—normal as well as abnormal.

Unlike autopsy pathology, the decisions made by the surgical pathologist are often rapid and occasionally immediate. The rendered diagnosis frequently precedes the patient’s treatment and in many cases influences or even dictates the exact nature of this treatment. In addition, the surgical pathologist also functions as a teacher or consultant. Such consultations should always benefit the patient even though the surgical pathologist works in a laboratory without true patient contact.

HISTORICAL PERSPECTIVE

In times past, the surgical pathologist was located in a division of surgery or at least closely affiliated with such a clinical department. Oftentimes, the examination of tissue removed from the living patient was relegated to the pathology resident. With such assignment came delays of pathology reports, and in some cases the report only stated “benign” or “malignant.” Under such conditions the clinical surgeon’s diagnoses and treatment recommendations were often much more appropriate than those of the undereducated and occasionally uninterested pathology resident. Even so, it was almost impossible to be a competent clinician and a skilled pathologist simultaneously. Still, in times past, there were those exceptional persons who were not only skilled pathologists, but who also introduced numerous important contributions to their respective surgical disciplines.

In the first half of the twentieth century, the technology of tissue fixation, staining procedures, and microscopic discrimination progressed rapidly. Immunostaining was initiated in the 1940s, and enzymatic immunochemistry and monoclonal antibody staining became widely used in the 1970s and 1980s. Both scanning and transmission electron microscopy were available for use in human tissue diagnostics in the 1960s. These techniques as well as many others allowed the surgical pathologist the ability to help recognize and categorize a multitude of human pathologic disease states.

Even though the title “surgical pathology” implies surgery, the surgical pathologist is actually closely related to all medical disciplines. These medical or dental professionals have the unique position of seeing both the beginning of disease and the end point of many pathological processes. The surgical pathologist must have an extensive background in clinical medicine/surgery, but he must also know his own specialty quite thoroughly. With the utilization of all the available diagnostic modalities comes the surgical pathologist’s obligation to correctly discern among such testing methods, thus leading to a useful definitive diagnosis rather than just a myriad of superfluous esoterica.

SURGEON/PATHOLOGIST INTERACTION

In order for any pathological test to be “successful” (i.e., beneficial for the patient), the pathologist and the surgeon must communicate well. Such a relationship cannot be stressed enough. It is important that each professional know the other’s skills well enough that the ultimate outcome will be excellent patient care. Guided interaction should be the norm rather than the exception.

A problem that always seems to accompany laboratory analysis is a reasonable timetable for results. Some studies such as the frozen section can render an immediate diagnosis. Others, such as the culture of mycoplasm, may take several weeks. During this time frame, the surgeon often becomes quite anxious since these clinicians are the ones who must deal with the patient and the related family. Realistic expectations should arise from prior reporting of earlier patient studies as well as turn-around times routinely published by the laboratory. The surgeon should always stay attuned to the needs of the pathologist. If the surgeon considers lymphoma as the diagnosis, tissue should routinely be submitted fresh for immunologic assays. Tissue that needs a bacterial or fungal culture should not be submitted in formalin. Technical advances must be followed closely by both the surgeon and the pathologist. In this way, such improper specimen handling will be discouraged.

SURGEON/PATHOLOGIST INTERACTION

In order for any pathological test to be “successful” (i.e., beneficial for the patient), the pathologist and the surgeon must communicate well. Such a relationship cannot be stressed enough. It is important that each professional know the other’s skills well enough that the ultimate outcome will be excellent patient care. Guided interaction should be the norm rather than the exception.

A problem that always seems to accompany laboratory analysis is a reasonable timetable for results. Some studies such as the frozen section can render an immediate diagnosis. Others, such as the culture of mycoplasm, may take several weeks. During this time frame, the surgeon often becomes quite anxious since these clinicians are the ones who must deal with the patient and the related family. Realistic expectations should arise from prior reporting of earlier patient studies as well as turn-around times routinely published by the laboratory. The surgeon should always stay attuned to the needs of the pathologist. If the surgeon considers lymphoma as the diagnosis, tissue should routinely be submitted fresh for immunologic assays. Tissue that needs a bacterial or fungal culture should not be submitted in formalin. Technical advances must be followed closely by both the surgeon and the pathologist. In this way, such improper specimen handling will be discouraged.

BIOPSY TECHNIQUES

The basic technique of tissue biopsy and its subsequent handling has undergone very few changes since its introduction many years ago. It is without a doubt the most important duty of the surgical pathologist. The surgeon should always remember that the pathologist cannot diagnose a disease if the biopsy material is not representative of that disease. Small biopsy specimens taken with an electrocautery knife are often not satisfactory because of the cautery artifact. Biopsies taken of a tumor near an ulcerated area frequently show only necrosis and inflammation. If the patient presents with a large aggregate of lymph nodes, a biopsy of a peripheral node may not be as representative as one from the central portion of the mass. If a lesion is ulcerated, the biopsy should include both normal tissue as well as the ulcer. Although it is oftentimes not the ideal tissue fixative, 10% formalin is the type most often used. The biopsied tissue should be placed into this fixative immediately.

FROZEN SECTION

The development of the cryostat in the late 1950s led to the use of the frozen section in most hospital laboratory departments. It was during this time that the frozen section was accepted as a valid diagnostic test. A frozen section should be accurate, rapid, and reliable. The use of this test demands that the surgical pathologist have a well-balanced clinical background as well as be proficient in the needed microscopic interpretations. Before viewing the frozen tissue, the pathologist must be thoroughly briefed on the clinical nature of the patient’s problem. As he views the tissue, the pathologist should ask the surgeon’s advice on the correct area of tissue to be examined. Often as not, complete sampling of large tissue specimens is limited because of time constraints. As such, judicious sampling is of paramount importance. Similar, although not identical, problems arise in the sampling of smaller tissue biopsies. If at all possible, some of the tissue should be saved for permanent microscopic examination and only a tiny fragment used in the frozen section diagnosis. Once again, discussion of the case with the involved surgeon can often make a tremendous difference in the ultimate outcome of the biopsy material.

The frozen section can be of great value to the surgeon, but both the surgeon and pathologist should agree that such a test only be used when the interpretation can provide information of immediate or ultimate value in the patient’s management. A diagnostic frozen section should not be used if the definitive surgery is contemplated to be at a later time. The surgeon should remember that the tissue examination using frozen tissue is much more difficult than when using fixed tissue. Examples of non-controversial indications for the use of a frozen section include:

  • 1.

    The diagnosis influencing immediate surgical management

  • 2.

    The lesion not accessible or the patient not amenable to preoperative biopsy

  • 3.

    Preoperative biopsy attempted but not successful

  • 4.

    Staging of malignant neoplasms

  • 5.

    Assessing the adequacy of excision

  • 6.

    Procuring tissue for ancillary studies

The surgeon and the pathologist should carefully consider all the viable options prior to the frozen section. In such cases the surgical pathologist should make sure the following conditions are met: (1) There is no risk of compromising the tissue specimen, (2) there is significant tissue for all ancillary studies, (3) there is a high probability of rendering the correct diagnosis, and (4) there is little risk of conveying incorrect diagnostic information. Then and only then should the frozen section proceed.

ASPIRATION BIOPSY TECHNIQUES

Fine needle aspiration (FNA) biopsy has enjoyed a rebirth in the last 15-20 years. As a very cost-effective procedure, the FNA is now a commonly used method of diagnosis when dealing with neoplastic disease. This procedure is performed by internists, surgeons, and pathologists. The advent of various radiographic imaging modalities such as CT and ultrasound has stimulated radiologists to use FNA biopsies as well.

Only gold members can continue reading. Log In or Register to continue

Jun 3, 2016 | Posted by in Oral and Maxillofacial Surgery | Comments Off on PATHOLOGY OF THE ORAL AND MAXILLOFACIAL REGION: DIAGNOSTIC AND SURGICAL CONSIDERATIONS
Premium Wordpress Themes by UFO Themes