Synopsis
Surgical pathology of the head and neck encompasses many procedures, especially when it comes to complex diseases like cancer in the head or neck region. Usually, surgical pathologist needs to evaluate a wide range of specimens such as those from the ear, nasal cavity, sinuses, oral cavity, and others. The head and neck region of the body is particularly prone to numerous diseases. In cases where doctors suspect the presence of such conditions, a biopsy can be performed, and the obtained specimen is then sent to a surgical pathologist for a thorough examination and appropriate testing. This critical evaluation aids in establishing an accurate diagnosis and assists in determining the subsequent course of treatment for the patient. Because of the complexity of the work, the selection of the proper device can be quite a challenge, but it is a basic requirement. In the following article, we will briefly introduce what the surgical pathology of the head and neck involves.
Surgical Pathology of Head and Neck in Medical Procedures
Head and neck pathology is among the most generalized of all surgical pathology services. It encompasses diverse organs within a compact anatomical space. Head and neck pathology encompasses the evaluation of a broad spectrum of specimens. These specimens originate from various anatomical regions, including the middle and external ear, nasal cavity and sinuses, larynx and pharynx, oral cavity, salivary glands, thyroid and parathyroid glands, as well as soft tissue and bones. These regions are particularly vulnerable to a myriad of conditions or ailments. Both cancerous and non-cancerous tumors, infections, inflammations, and other conditions have the potential to disrupt the proper functioning of these structures, consequently posing a threat to the overall well-being of the body.
The Practice of Surgical Pathologists
If doctors suspect something suspicious in the head and neck region, they may order a biopsy and send the sample for examination and analysis. You usually examine the samples under a microscope and carry out subsequent tests, if needed, to set up a diagnosis.
Specialized Expertise
The head and neck pathology service typically offers specialized expertise in evaluating head and neck lesions, including tumors affecting the thyroid, salivary glands, and upper respiratory tract. This comprehensive range of services encompasses advanced techniques such as in situ hybridization, electron microscopy, and immunohistochemistry. Moreover, the service may also provide intraoperative consultations via state-of-the-art microscopes such as iO:M8 Microscope and Scanner, and conducts a thorough review of surgical pathology specimens.
Growing Concerns
In recent years, there has been a significant increase in the incidence of head and neck carcinomas. One intriguing aspect of this trend is the emergence of sinonasal tract tumors, which necessitate specific diagnostic testing. Immunohistochemical and molecular studies, including EBV and HPV testing, as well as DNA/RNA next-generation sequencing, are commonly employed procedures for these diseases. Sinonasal tract tumors occasionally exhibit a predominantly exophytic papillary growth pattern with mature squamous differentiation. Furthermore, there may be an additional component comprising atypical, less differentiated basaloid tumor cells infiltrating the surrounding stroma. In some cases, marked inflammation is evident. It is crucial to consider the possibility of morphological overlap between different entities during the process of histopathological diagnosis.
Case study: Surgical Pathology of Sinonasal Carcinoma
Martin Wartenberg et al., from the Institute of Tissue Medicine and Pathology, University of Bern, conducted a case study of a 32-year-old, healthy, actively smoking male patient who had a five-month history of pain in the left upper jaw. He was referred to a dentist, and after treatment that included the extraction of tooth 25 (central incisor), the wound healing delay was accompanied by a persistent oroantral fistula. On examination, the fistula was found to be localized at the site of the extracted tooth and the alveolar ridge of the posterior part was enlarged.
Biopsy Obtained
The first biopsy showed chronic-active inflammatory changes. A post-biopsy CT scan of the paranasal sinuses showed a large osseous defect and bone erosion at the site of the extracted tooth with complete opacification of the left maxillary sinus. Despite the inflammatory process that was shown first by biopsy, there was doubt about malignancy during the observation. Second, a larger biopsy was performed a month later and it revealed a non-keratinizing squamous cell carcinoma.
Whole Body Test
For staging purposes and resection planning, a whole-body FDG-PET/CT was performed, showing metabolically enhanced osseous destruction in the left maxillary sinus. The patient was discussed by the tumor board with the consensus that the disease was staged as cT2 cNo cMo and that primary resection was required. A hemimaxillectomy with wide margins was performed. The patient also underwent a selective neck dissection level I-III on the left side. That was followed by the reconstruction of the defect with a superficial circumflex iliac artery-based iliac bone-free flap.
Surgical Pathology Procedures Followed in the Case
Surgical pathology of the documented-case study included the initial biopsies involving an exophytic-papillomatous, partly inverted tumor with squamous differentiation without unequivocal evidence of invasion. Based on the clinical context of a prior tooth extraction with persistent oroantral fistula, differential diagnostic considerations involved prominent reactive inflammatory changes as well as exophytic-papillomatous, well-differentiated carcinoma. Mucocytes were not detected in the Alcian-Blue-PAS-stain. Despite abundantly admixed granulocytes, a sinonasal papilloma couldn’t be confirmed. The rather advanced squamous differentiation, limited cytologic atypia, and significant inflammation complicated the diagnosis.
In-depth Analysis
The second biopsy showed small, discohesive collections of epithelial cells infiltrating the stroma with focal transformation into larger, basaloid aggregates without clear demarcation by a basement membrane, militated against the diagnosis of a reactive process. The time course and clinical-radiological features showed a malignant process. The interpretation result was a reactive squamous epithelial proliferation. That was revised with the descriptive diagnosis of the exophytic-papillomatous and partly endophytic growing carcinoma.
External Pathologic Consultation
A diagnosis of non-keratinizing squamous cell carcinoma was rendered. The assumption was that the lesion originated from the sinonasal tract rather than the mucosa of the oral cavity based on the latest WHO classification of head and neck tumors. The testing of HPV-DNA, as also EBV-RNA and in situ hybridization was done. These tests, as also p16 immunohistochemistry tests were negative.
Additional Prerequisite
There was also a requirement to address the differential diagnosis of a DEK::AFF2 fusion-associated carcinoma and molecular profiling was done. Fusion-associated carcinomas are an emerging entity in the sinonasal tract, with the majority showing a strikingly bland histologic appearance and overlap with so-called Schneiderian carcinomas. The detection of DEK::AFF2 gene fusion allows for more accurate classification and prognostic assessment. The surprising thing is that no DEK::AFF2, but a NUT::NSD3 fusion was detected and that led to the diagnosis of NUT carcinoma.
Matching Speckled Type Positivity
NUT immunohistochemistry showed a matching speckled type positivity in the majority of the carcinoma cells, corroborating the diagnosis and visualizing the fusion product. The macroscopy of the following left-sided hemimaxillectomy was also done and it showed the main tumor originating in the maxillary sinus and breaking through the bone into the oral cavity. Together with the neck dissection, the final pathologic tumor staging was pT2 pNo Lo Vo Pn1, high-grade. It was also noted extensive perineural spread.
An Extensively Practiced Area
The field of surgical pathology about the head and neck represents one of the most extensive and frequently practiced areas within the discipline. It encompasses many procedures like analyzing head and neck lesions and tumors affecting the thyroid, salivary glands, and upper respiratory tract. Diverse types of procedures are applied depending on the nature of the head or neck ailment. Surgical pathology is especially complex when it comes to analyzing and reporting head and neck cancer.
Conclusion
Surgical pathology of the head and neck involves several procedures because the head and neck are the regions of the body where many organs are located. To successfully perform a surgical pathology analysis of specimens from the head and neck region, a surgical pathologist requires the best equipment in addition to specialized knowledge and experience. For example, often, surgical pathologists need to perform sophisticated tests to determine the nature of the cancer. That often involves staining, gene fusion, and similar procedures. Thus, utilizing the appropriate device is of utmost importance when conducting surgical pathology analysis.
