Cytology of head and neck squamous cell carcinoma variants

Acantholytic squamous cell carcinoma mimicking epithelioid angiosarcoma: A diagnostic challenge by cytology

Squamous cell carcinoma (SCC) is the most common malignancy of the head and neck region. Most cases present little diagnostic difficulty on fine needle aspiration (FNA), but unusual variants can be problematic. The authors report a case of the acantholytic SCC of the oral cavity in a 36-year-old male. The FNA showed hypercellularity, with malignant cells arranged in isolation, loosely cohesive groups and a linear configuration. Such cells were round to elongated, with vesicular nuclei and prominent nucleoli. Cells possessed occasional intracytoplasmic vacuoles, misinterpreted on FNA to be vasoformative features as seen in malignant endothelial cells. The cytologic diagnosis was "positive for malignancy, suggestive of angiosarcoma". A total excision was performed and by histology, the tumor was diagnosed as acantholytic SCC. The malignant cells were positive by immunostaining for AE1/AE3, p40, p63 and vimentin, but negative for CD31, CD34 and ERG. The intracytoplasmic vacuoles were PAS- and mucin-negative and negative for the above antibodies. Testing for HPV (molecular and p16 immunostaining) was negative. This case highlights the diagnostic challenges on cytology when malignant acantholytic squamous cells show intracytoplasmic vacuoles, and stresses how immunohistochemistry is important for distinguishing acantholytic SCC from other mimics.

NUT Carcinoma—An Underdiagnosed Malignancy

NUT carcinoma (NC) is a rare and highly aggressive malignancy with a dismal prognosis and a median survival of 6–9 months only. Although very few cases of NC are reported each year, the true prevalence is estimated to be much higher, with NC potentially widely underdiagnosed due to the lack of awareness. NC primarily occurs in midline structures including thorax, head, and neck; however, other sites such as pancreas and kidney are also affected, albeit at lower frequencies. NC is characterized by a single translocation involving the NUTM1 (NUT midline carcinoma family member 1) gene and different partner genes. The resulting fusion proteins initiate tumorigenesis through a mechanism involving BET (bromo-domain and extra-terminal motif) proteins such as Bromodomain-containing protein 4 (BRD4) and inordinate acetylation of chromatin, leading to the dysregulation of growth and differentiation genes. While no clinical characteristics are specific for NC, some histologic features can be indicative; therefore, patients with these tumor characteristics should be routinely tested for NUTM1. The diagnosis of NC using immunohistochemistry with a highly specific antibody is straightforward. There are currently no standard-of-care treatment options for patients with NC. However, novel therapies specifically addressing the unique tumorigenic mechanism are under investigation, including BET inhibitors. This review aims to raise awareness of this underdiagnosed cancer entity and provide all patients the opportunity to be properly diagnosed and referred to a clinical study.

Primary Thyroid NUT Carcinoma With High PD-L1 Expression and Novel Massive IGKV Gene Fusions: A Case Report With Treatment Implications and Literature Review

Background

Nuclear protein in testis (NUT) carcinoma (NC) is a rare and aggressive undifferentiated carcinoma that typically arises from midline supradiaphragmatic structures. It is uniquely driven by a NUT gene rearrangement on chromosome 15q14. Few thyroid NCs have been reported and there are no established treatment guidelines for NUT carcinoma.

Method

Ultrasound-guided fine needle aspiration smear was performed for the preoperative diagnosis of thyroid lesions. Cytopathology, histology, and immunochemical staining all indicated NC. Fluorescence in situ hybridization (FISH), qRT-PCR, and next-generation sequencing (NGS) were used to analyze the genetic characteristics of NC.

Results

We describe a rare case of thyrogenic NC in a 38-year-old male with cytological, histological, immunohistochemical, and genetic features. Cytological smears and histopathological specimens showed typical features of NC. Immunohistochemistry confirmed strong immunoreactivity with NUT, EMA, P63, TTF-1, and c-myc. CK19 was positive exclusively in sudden keratosis. No immunoreactivity was found for neuroendocrine markers. FISH was applied to isolate the NUT gene on chromosome 15q14. The NGS results revealed a BRD4-NUT gene fusion, which was further confirmed by RT-qPCR. Structural variation (SV) of NUTM1 occurred in the exon region, and the mutation site was 15q14. Moreover, BRD4 single-nucleotide variation (SNV) occurs in the 3′ UTR at mutation site 19p13.12. The PD-L1 combined predictive score was over 30%. The patient received chemotherapy, followed by programmed cell death 1 (PD-1) inhibition with camrelizumab, and died 10 months after surgery.

Conclusion

Thyroid NC is an extremely rare and fatal malignant tumor. It is necessary to consider NC when squamous differentiation is observed cytologically or histologically. NGS is an effective tool for obtaining the final diagnosis and obtaining a better understanding of tumor pathogenesis. A large number of IGKV gene fusions in addition to the BRD4-NUT fusion may play a role in the pathogenesis and immunotherapy response of NC. Immunotherapy for NC remains to be explored due to the rarity of this aggressive malignancy.

Application of integrated positron emission tomography/magnetic resonance imaging in evaluating the prognostic factors of head and neck squamous cell carcinoma with positron emission tomography, diffusion-weighted imaging, dynamic contrast enhancement and combined model

OBJECTIVES

This study was designed to investigate the distribution of the independent parameters of PET and MR in tumour differentiation and staging and to evaluate the diagnostic efficiency of the independent parameters and combined model of PET/MR in the tumour differentiation of head and neck squamous cell carcinoma (HNSCC).

METHODS

The patients with the preliminary diagnosis of HNSCC were included and underwent the integrated PET/MR The parameters included the diffusion-weighted imaging, dynamic contrast enhancement and PET. The correlations between different parameters and the distribution in groups of tumour differentiation and staging were analysed. The combined model was established with complementary PET/MR parameters. The diagnostic efficiency of the independent parameters and combined model in the tumour differentiation were analysed by receiver operating characteristic curve.

RESULTS

The correlations between the parameters of dynamic contrast enhancement and PET were most significant. There were significant differences between the well-differentiated group and the moderately/poorly differentiated group in terms of the mean values of apparent diffusion coefficient (ADC) and standardised uptake value (SUV) (p < 0.05). The distributions among different tumour stage groups were not statistically different in all the parameters. The diagnostic efficiency of tumour differentiation increased in the order of K_epmean, SUVmean, ADCmean, and the combined model.

CONCLUSIONS

Compared with the independent parameter, the combination of multiple parameters with PET/MR can further improve the diagnostic performance of tumour differentiation in HNSCC.

Effectiveness of fine-needle aspiration cytology in the diagnosis of lateral cervical nonthyroid tumors

Given that the clinical and radiological examinations of lateral cervical masses are not always sufficient for deciding on appropriate management, the cytological examination of the material obtained by fine-needle aspiration might be an efficient tool in the preoperative investigation of these lesions.In this prospective cross-sectional study we evaluated the efficacy and diagnostic accuracy of fine-needle aspiration cytology in the assessment of lateral cervical nonthyroid tumors, by comparing its results with those of histopathology.A total of 58 patients with lateral cervical masses were included. Preoperative cytological results were compared with the histopathologic examination of surgical specimens.Both cytology and histology indicated that malignant tumors outnumbered benign lesions (62% vs 38%), with 88.9% of malignancies presenting in patients aged >50 years, but cytology was less effective at differentiating between benign and nontumor lesions. Cytology had 76.5% specificity and 78.1% sensitivity for identifying malignant lateral cervical lesions, and there was a concordance between the two diagnostic tests (McNemar test, P = 0.17, κ = 0.50, P <0.001).Fine-needle aspiration cytology is a simple, quick, and effective procedure that can aid in the preoperative evaluation of lateral cervical masses by differentiating benign tumors and inflammatory processes from malignancies and thus help in determining a subsequent therapeutic strategy.

Assessment of fine needle aspiration feasibility and specimen adequacy for molecular diagnostics of benign vocal fold lesions

OBJECTIVES/ HYPOTHESIS

The use of molecular testing is becoming more significant for the diagnosis and classification of disease. The application of fine-needle aspiration (FNA) biopsy as the means of sampling lesions in union with molecular testing could be a powerful combination in laryngology. The objectives of this study were to investigate 1) if FNA was feasible to sample benign vocal fold lesions; 2) if FNA samples provided sufficient RNA quality for molecular analysis; and 3) if gene expression of FNA samples matched paired surgical excised specimens.

STUDY DESIGN

Prospective cross-sectional.

METHODS

Fifteen vocal fold specimens were obtained from adult patients undergoing routine surgical removal for benign vocal fold lesions using FNA and surgical excision. Comparisons were made between FNA and excision biopsies for RNA quality. Correlative analysis was completed for RNA expression of nine genes, including decorin (DCN), connective tissue growth factor (CTGF), vascular endothelial growth factor (VEGF), collagen type VI alpha 3 (COL6A3), superoxide dismutase 1 (SOD1), glutathione S-transferase (GST2), collagen type I alpha 2 (COL1A2), ATP binding cassette (ABC), and procollagen I alpha 1 (COL1A1).

RESULTS

FNA and excision samples demonstrated similar RNA quality (P > 0.05). Per gene expression, four out of nine genes were moderately correlated between the paired samples (P < 0.05).

CONCLUSIONS

FNA of the vocal fold lamina propria is technically feasible to perform. Further improvement in the FNA technology is desirable to optimize RNA quality for reliable gene expression analysis.

Acantholytic squamous cell carcinoma in upper aerodigestive tract: histopathology, immunohistochemical profile and epithelial mesenchymal transition phenotype change

Acantholytic squamous cell carcinoma is a rare variant of squamous cell carcinoma in the mucosa of upper aerodigestive tract. Histomorphologically, acantholytic squamous cell carcinoma may lose the typical features of conventional squamous cell carcinoma and mimic other epithelial or mesenchymal malignancies due to advanced acantholysis and dyskeratosis. Because of its rarity, information of prognosis, pathologic features and immunohistochemical profiles is limited. We have studied clinicopathologic features and immunohistochemical profiles of four acantholytic squamous cell carcinoma cases arising from upper aerodigestive tract. Clinical results indicate an aggressive biologic behavior. Morphologically, all tumors revealed significant acantholysis with separation of tumor cells and intratumoral spaces. The tumor cells were highly pleomorphic and growth patterns were variable. In immunohistochemical studies, all tumor cells revealed positive reactions for AE1/AE3 and p63 supporting a squamous epithelial origin. In contrast to conventional aerodigestive squamous cell carcinoma, acantholytic squamous cell carcinoma showed significant reductions of cytokeratin19, E-cadherin and concomitant up-regulation of vimentin expression. Both morphologic features and immunohistochemical profiles indicate that acantholytic squamous cell carcinoma has acquired an epithelial mesenchymal transition phenotype. However, in contrast to other solid malignant tumors, the epithelial mesenchymal transition phenotype change in acantholytic squamous cell carcinoma is not limited to the invasive front of the peripheral tumor but, rather, diffusely involves entire neoplastic lesion. In addition, because cytokeratin 19 staining is attenuated, this would be an insensitive marker for following up and/or in detecting disseminated tumor cells in cases of acantholytic squamous cell carcinoma in upper aerodigestive tract.

Efficacy of oral brush cytology in the evaluation of the oral premalignant and malignant lesions

Objective:

In the present study, oral brush cytology of premalignant and malignant lesions was performed using tooth brush. The cytopathological diagnosis of brush cytology was compared with that of punch biopsy. The reliability of oral brush cytology using tooth brush was assessed in terms of sensitivity and specificity.

Materials and Methods:

A total of 67 patients, 32 premalignant lesions and other 35 frank oral carcinomas, were included in the study. All patients underwent oral brush cytology using a toothbrush followed by punch biopsy. Sensitivity, specificity, positive and negative predictive values were calculated. Cytopathology and histopathology of premalignant and malignant lesions were compared using Mann-Whitney U test. Inter- and intra-examiner reliability was calculated using Rank-correlation coefficient.

Results:

Two in premalignant group and five in malignant group were marked insufficient. 18% of cases were false negatives. The sensitivity, specificity, positive predictive value and negative predictive value were 77%, 100%, 100% and 38%, respectively. Statistical analysis showed P>0.05, suggesting that there is no significant difference between histopathology and brush cytology in assessing both premalignant and malignant lesions. Inter- and intra-examiner reliability were 99.22% and 99.77%, respectively.

Conclusion:

Brush cytology using a tooth brush is reliable and can be easily performed with less cost and discomfort to the patient. It is useful in those situations when a patient refuses to have a biopsy performed or when medically compromised patients would be exposed to unnecessary surgical risks. It can be used for screening for suspicious oral lesions, and may have applications in resource-challenged areas.

Spindle cell carcinoma of the tongue: a rare tumor in an unusual location

Spindle cell carcinoma is a rare biphasic tumor consisting of epithelial and mesenchymal components. Presence of this tumor type in the tongue has rarely been reported. Herein, a case of 55-year-old woman who presented with a polypoid lesion at her tongue has been reported. Surgery was performed and pathologic examination revealed a spindle cell carcinoma. We present this rare tumor with an unusual location to contribute in part to the better understanding and awareness of this rare malignancy.

Temporal bone verrucous carcinoma: outcomes and treatment controversy

Verrucous carcinoma is a rare tumor that presents in the head and neck with the most common sites being the oral cavity and larynx. Fourteen cases of verrucous carcinoma of the temporal bone have been described in literature; this study aims to examine treatment outcomes and discuss the controversy surrounding postoperative radiation. The study design included a literature review along with individual case report in the setting of a tertiary care medical center. Outcome analysis of all cases of verrucous carcinoma of the temporal bone, which are documented in the English literature, and presentation of a single patient report including gross, histologic and radiologic analyses were performed. The longest recorded survival for verrucous carcinoma of the temporal bone occurs in patients treated with surgery alone. Poorer outcomes for patients treated with adjuvant (chemo)radiation may be due to more advanced stage of disease at the time of treatment. Early reports of radiation leading to tumor dedifferentiation or early recurrence are not supported by more recent studies. Whether adjuvant radiation therapy is indicated in verrucous carcinoma of the temporal bone remains controversial.