Head and Neck Pathology

Salivary gland carcinomas (SGCs) are a rare group of malignant neoplasms of the head and neck region. MicroRNAs (miRNAs) are a class of small non-coding RNAs that have been associated with the control biological process and oncogenic mechanism by the regulation of gene expression at the post-transcriptional level. Recent evidence has suggested that miRNA expression may play a role in the tumorigenesis and carcinogenesis process in SGCs. This review provides a comprehensive literature review of the role of miRNAs expression in SGCs focusing on the diagnostic, prognostic, and therapeutic applications. In this review, numerous dysregulated miRNAs have demonstrated an oncogenic and suppressor role in SGCs. In the future, these miRNAs may eventually constitute useful diagnostic and prognostic biomarkers that may lead to a better understanding of SGCs oncogenesis. Additionally, the development of therapeutic agents based on miRNAs may be a promising target in SGC treatment.

Laryngeal mesenchymal neoplasms are rare, with smooth muscle tumors comprising a small subset. Specifically, Epstein-Barr virus (EBV)-associated smooth muscle tumors are exceptionally rare, lacking a comprehensive evaluation of their clinical and histologic features. Two patients (a 59 year old male and 51 year old female) had received renal transplants 156 and 240 months, respectively prior to onset of laryngeal symptoms. Supraglottic polypoid masses were identified and removed conservatively. Histologically, the tumors were hypercellular, showing alternating light and dark areas, the latter composed of primitive appearing round cells, while a more characteristic spindled tumor cell population was noted in the remaining areas. Cytoplasmic vacuoles were noted adjacent to the nucleus. There was no tumor necrosis or pleomorphism, but increased mitotic figures (11–12/2 mm2) were seen, without atypical forms. The tumor cells were strongly immunoreactive with smooth muscle actin and smooth muscle myosin heavy chain and with Epstein-Barr virus encoded RNA (EBER) by in situ hybridization. These patients were reviewed in the context of a thorough English literature review, which demonstrates a wide age range at presentation without a sex predilection, but with most patients from specific ethnic groups (Chinese, Thai, Pilipino). Three-quarters of patients are part of multifocal disease and the majority are post-renal transplantation patients. Conservative management seems to yield the best overall outcome for these indolent tumors. In conclusion, EBV-associated smooth muscle tumors should be considered in any immunocompromised patient with a head and neck smooth muscle tumor, especially when EBER is documented by in situ hybridization. Conservative management may be employed, even when multifocal tumors are documented.

Dentinoid is an integral part of some odontogenic tumors. This article describes the clinico-pathological features of three cases of odontogenic carcinomas with dentinoid (OCD). A comparison of these with previously reported cases of dentinoid-producing epithelial odontogenic tumors allowed us to identify another six cases that may be considered as examples of OCD. Six cases occurred in the mandible and three in the maxilla, all developing behind the canines. There was no sex predilection (five men and four women; age range 14–61 years, mean 38.1). Pain or discomfort was mentioned in five cases, four of which showed tooth resorption. All cases appeared initially as well-defined radiolucencies, five of which showed variable amounts of calcified material. Recurrences were recorded in three instances, but no evidence of metastasis has been found. Seven cases were composed predominantly or entirely of clear cells, usually with minimal cellular atypia and variable mitotic activity; however, in all cases there was evidence of tumor infiltration into adjacent tissues, including the presence of perineural invasion in two tumors. Those cases in which no reference was made to the presence of clear cells exhibited evident mitotic activity and cellular pleomorphism. The epithelium in OCD does not produce buds or enamel organ-like structures such as those found in ameloblastic fibro-dentinoma and this tumor does not contain a mesenchyme-like connective tissue resembling dental papilla as observed in several mixed odontogenic tumors. Based on the existing data and the present series of cases, OCD appears to represent a distinct entity.

Castleman disease is most commonly found in the mediastinum, while the head and neck is the second most common location. The disease exists in a unicentric and multicentric variety and is usually successfully treated with surgical resection alone. Early identification is important for treatment planning. Castleman disease has been reported to mimic other disease processes, however there has been only one report of the disease mimicking a nerve sheath tumor in the parapharyngeal space. Here we report the second case of Castleman disease mimicking a schwannoma in the parapharyngeal space.

A 67-year-old female with a history of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) presented with right sided otalgia and a 2-3 cm firm, tender right posterior parotid mass. Fine needle aspiration biopsy (FNAB) established a diagnosis of acinic cell carcinoma (AciCC). Further workup demonstrated lung nodules which were confirmed by FNAB to represent metastatic AciCC. A right radical parotidectomy with sacrifice of the facial nerve, segmental mandibulectomy, and selective neck dissection (levels II-IV) was performed. Microscopically, the tumor displayed an infiltrative border with a solid multinodular growth pattern and fibrosclerotic septation. The tumor was composed mainly of uniform cells with abundant eosinophilic granular cytoplasm with round nuclei with prominent nucleoli. Nuclei were fairly monomorphic, mitotic counts were 3-4 per 2mm2 and there was no necrosis despite the aggressive growth pattern. An anti-mitochondrial immunohistochemical stain showed strong reactivity in the tumor cells, with an internal positive control of adjacent striated ducts. An immunohistochemical stain for NR4A3 demonstrated strong nuclear reactivity in the tumor cells. Electron microscopy highlighted the tumor cells with numerous mitochondria and distinctive electron dense intramitochondrial inclusions. Concurrent CLL/SLL was identified on histologic examination of the lymph nodes, but they were free of AciCC. After eight weeks of follow-up, she tolerated the surgery well and is currently receiving radiation therapy to the parotid and neck. In this illustrative case, we justify the oncocytic designation of AciCC by morphology, immunohistochemistry, and electron microscopy.

Epithelial dysplasia (ED) grading systems are criticized for low reliability. The effects of diagnostic tests or stains on reducing examiner variability in grading ED of the upper aerodigestive tract have not been investigated. The study aim was to examine the effectiveness of cytokeratin 19 (K19) immunostain on enhancing inter and intraexaminer reliability of ED grading and to reiterate the relation of K19 positivity with epithelial keratinization. The study sample consisted of 122 paraffin blocks that fulfilled the inclusion criteria. Each paraffin block had three sections cut: one immunostained for K19 and two for hematoxylin and eosin stain (H&E). Each examiner graded the study sample in six rounds; three using H&E stain only and three using paired K19–H&E stains. The study examiners were three American-Board certified practicing oral pathologists. The results were analyzed using Krippendorff’s alpha, ROC curve, Chi square test and binary logistic regression. Upon the use of paired K19–H&E stains the results showed that the intraexaminer reliability coefficients of grading were improved from 0.70, 0.69, 0.78 to 0.73, 0.88, 0.91 for examiners 1, 2, and 3 respectively. Reliability coefficients for inter-examiners improved from 0.55 to 0.73 (Krippendorff alpha). The accuracy of identifying the diseased cases (high-grade dysplasia) increased from 0.82 to 0.94 (ROC curve). Binary logistic regression revealed that K19 positivity is negatively associated with hyperkeratinization of surface epithelium (P = 0.001). To conclude, for grading non-keratinized epithelial dysplastic lesions of the upper aerodigestive tract, paired K19–H&E stains proved to reduce inter and intra-examiner variability by highlighting the extension of dysplastic epithelial cells within epithelial thickness, thus identifying the involved epithelial third and assigning a more reliable and better reproducible grade.

Localized juvenile spongiotic gingival hyperplasia (LJSGH) is a gingival lesion with unique clinicopathologic features that may involve synchronously multiple sites. We present a case with lesions clinically consistent with LJSGH in four jaw quadrants, confirmed by biopsy and review the English literature on multifocal LJSGH cases. A 19 year-old woman presented with circumscribed, erythematous overgrowths on the right and left maxillary and mandibular gingiva. With the provisional diagnosis of multifocal LJSGH, total excision of four maxillary lesions was performed. Clinical, microscopic and immunohistochemical examination with cytokeratin 19 confirmed the diagnosis of LJSGH in multiple sites. The excised lesions showed partial to complete recurrence after 4 months, while spontaneous regression of all but one lesion was observed after 15 months. Twenty cases with synchronous involvement of the gingiva of at least two teeth were previously reported. Their clinical features were comparable to that of solitary LJSGH. Only one case involved all four jaw quadrants. Spontaneous remission has not been documented before. The recognition of multiple lesions with clinicopathologic features diagnostic of LJSGH in the same adult patient argue against the designations “localized” and “juvenile”. Recurrences are common, while remission might occur.

Previous data has shown that the risk of nodal metastases is significantly greater for classical papillary thyroid carcinoma (PTC) as compared to the follicular variant (FVPTC). Given a recent change in diagnostic paradigm and definition of the noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) we intended to investigate if there remains a significant difference in nodal involvement between classical PTC and FVPTC. A 6-year retrospective review of all cases with FVPTC in the diagnostic line from the University of Utah/ARUP Laboratories was conducted. Two pathologists reviewed the remaining cases using the recently described histologic criteria of NIFTP to determine the total number the FVPTCs fitting the new classification paradigm. Histologic and clinical follow-up was tracked for all patients to determine the rate of nodal disease for all groups. 127 cases were identified using the above listed criteria. Forty-seven cases (37%) were classified as NIFTPs. None of the 47 patients had nodal disease either at the time of surgery or on follow-up. Twenty-eight cases met the current criteria for FVPTC (21%); of these 7/28 (25%) had evidence of nodal disease. By comparison, 17/45 (38%) of patients with mixed classical and FVPTC had nodal disease. Overall, there was no statistically significant difference in the risk of nodal metastasis between the pure FVPTC and mixed classical/FVPTC groups (p = 0.43). Our data indicates that implementing new definition for FVPTC will narrow the gap in the risk of nodal metastases between the classical PTC and FVPTC histologic subtypes.