Jiang RT, Wang JW, Peng S, Huang TC, Wang C, Cannella F, Chang YN, Viscidi RP, Best SRA, Hung CF, Roden RBS.
PMID: 28515303 | DOI: 10.1128/JVI.00699-17
Mus musculus Papillomavirus1 (MmuPV1/MusPV1) induces persistent papillomas in immunodeficient mice but not common laboratory strains. To facilitate study of immune control, we sought an outbred and immune competent laboratory mouse strain in which persistent papillomas could be established. We found that challenge of SKH1 mice (Crl:SKH1-Hrhr) by scarification on their tail with MmuPV1 resulted in three clinical outcomes: 1) persistent (>2 months) papillomas (∼20%), 2) transient papillomas that spontaneously regress typically within 2 months (∼15%), 3) no visible papillomas and viral clearance (∼65%). SKH1 mice with persistent papillomas were treated using a candidate preventive/therapeutic naked DNA vaccine that expresses human calreticulin (hCRT) fused in frame to MmuPV1 E6 (mE6) and E7 (mE7) early proteins and residues 11-200 of late protein L2 (hCRTmE6/mE7/mL2). Three intramuscular DNA vaccinations were delivered biweekly via in vivo electroporation, and both humoral and CD8 T cell responses were mapped and measured. Previously persistent papillomas disappeared within 2 months after the final vaccination. Coincident virologic clearance was confirmed by in situ hybridization and failure of disease to recur after CD3 T cell depletion. Vaccination induced a strong mE6 and mE7 CD8+ T cell response in all mice, although significantly lower in mice that initially presented with persistent warts as compared with those that spontaneously cleared their infection. An HPV16-targeted version of the DNA vaccine also induced L2 antibodies and protected mice from vaginal challenge with HPV16 pseudovirus. Thus MmuPV1 challenge of SKH1 mice is a promising model of spontaneous and immunotherapy-directed clearance of HPV-related disease.IMPORTANCE High risk type human papillomaviruses (hrHPV) cause 5% of all cancer cases worldwide, notably cervical, anogenital and oropharyngeal cancers. Since preventative HPV vaccines have not been widely used in many countries, and do not impact existing infections, there is considerable interest in the development of therapeutic vaccines to address existing disease and infections. The strict tropism of HPV requires the use of animal papillomavirus models for therapeutic vaccine development. However, MmuPV1 failed to grow in common laboratory strains of mice with an intact immune system. We show that MmuPV1 challenge of the outbred immunocompetent SKH1 strain produces both transient and persistent papillomas, and that vaccination of the mice with a DNA expressing an MmuPV1 E6E7L2 fusion with calreticulin can rapidly clear persistent papillomas. Further an HPV16-targeted version of the DNA can protect against vaginal challenge with HPV16 suggesting the promise of this approach to both prevent and treat papillomavirus-related disease.
J Otolaryngol Head Neck Surg.
Brown RE, Naqvi S, McGuire MF, Buryanek J, Karni RJ.
PMID: 28818106 | DOI: 10.1186/s40463-017-0230-2
Abstract
BACKGROUND:
Human papillomavirus (HPV) has been identified as an etiopathogenetic factor in oropharyngeal squamous cell carcinoma. The HPV E6 and E7 oncogenes are instrumental in promoting proliferation and blocking differentiation leading to tumorigenesis. Although surgical intervention can remove such tumors, the potential for an etiologic field effect with recurrent disease is real. A downstream effector of E7 oncoprotein, enhancer of zeste homolog 2 (EZH2), is known to promote proliferation and to pose a block in differentiation and in turn, could lead to HPV-induced malignant transformation. However, the EZH2 pathway is amenable to low toxicity therapies designed to promotedifferentiation to a more benign state and prevent recurrent disease by inhibiting the incorporation of HPV into the genome. This is the first study using clinical specimens to demonstrate EZH2 protein expression in oropharyngeal carcinoma (OPC).
METHODS:
The study included eight patients with oropharyngeal carcinoma, confirmed p16INK4a- positive by immunohistochemistry (IHC). The tissue expression of E6/E7 messenger RNA (mRNA) was measured by RNAscope™ in-situ hybridization technology. Expression of EZH2, Ki-67, and mitotic indices were assessed by morphoproteomic analysis. Biomedical analytics expanded the results with data from Ingenuity Pathway Analysis (IPA) and KEGG databases to construct a molecular network pathway for further insights.
RESULTS:
Expression of E6 and E7 oncogenes in p16INK4a- positive oropharyngeal carcinoma was confirmed. EZH2 and its correlates, including elevated proliferation index (Ki-67) and mitotic progression were also present. Biomedical analytics validated the relationship between HPV- E6 and E7 and the expression of the EZH2 pathway.
CONCLUSION:
There is morphoproteomic and mRNA evidence of the association of p16INK4a-HPV infection with the E6 and E7 oncogenes and the expression of EZH2, Ki-67 and mitotic progression in oropharyngeal carcinoma. The molecular network biology was confirmed by biomedical analytics as consistent with published literature. This is significant because the biology lends itself to targeted therapeutic options using metformin, curcumin, celecoxib and sulforaphane as therapeutic strategies to prevent progression or recurrence of disease.
Stolnicu S, Barsan I, Hoang L, Patel P, Terinte C, Pesci A, Aviel-Ronen S, Kiyokawa T, Alvarado-Cabrero I, Pike MC, Oliva E, Park KJ, Soslow RA.
PMID: 29135516 | DOI: 10.1097/PAS.0000000000000986
We sought to classify endocervical adenocarcinomas (ECAs) based on morphologic features linked to etiology (ie, human papillomavirus [HPV] infection), unlike the World Health Organization 2014 classification. The International Endocervical Adenocarcinoma Criteria and Classification (IECC criteria), described herein, distinguishes between human papillomavirus-associated adenocarcinoma (HPVA), recognized by the presence of luminal mitoses and apoptosis seen at scanning magnification, and no or limited HPVA features (nonhuman papillomavirus-associated adenocarcinoma [NHPVA]). HPVAs were then subcategorized based on cytoplasmic features (mostly to provide continuity with preexisting classification schemes), whereas NHPVAs were subclassified based on established criteria (ie, gastric-type, clear cell, etc.). Complete slide sets from 409 cases were collected from 7 institutions worldwide. Tissue microarrays representing 297 cases were constructed; immunohistochemistry (p16, p53, vimentin, progesterone receptor) and chromogenic in situ hybridization using an RNA-based probe set that recognizes 18 varieties of high-risk HPV were performed to validate IECC diagnoses. The 5 most common IECC diagnoses were usual-type (HPVA) (73% of cohort), gastric-type (NHPVA) (10%), mucinous adenocarcinoma of HPVA type, including intestinal, mucinous not otherwise specified, signet-ring, and invasive stratified mucin-producing carcinoma categories (9%), clear cell carcinoma (NHPVA) (3%) and adenocarcinoma, not otherwise specified (2%). Only 3 endometrioid carcinomas were recognized and all were NHPVA. When excluding cases thought to have suboptimal tissue processing, 90% and 95% of usual-type IECC cases overexpressed p16 and were HPV, whereas 37% and 3% of NHPVAs were p16 and HPV, respectively. The 1 HPV gastric-type carcinoma was found to have hybrid HPVA/NHPVA features on secondary review. NHPVA tumors were larger and occurred in significantly older patients, compared with HPVA tumors (P<0.001). The high-risk HPV chromogenic in situ hybridization probe set had superior sensitivity, specificity, and positive and negative predictive values (0.955, 0.968, 0.992, 0.833, respectively) compared with p16 immunohistochemistry (0.872, 0.632, 0.907, 0.545, respectively) to identify HPV-related usual carcinoma and mucinous carcinoma. IECC reliably segregates ECAs into HPVA and NHPVA types using morphology alone. This study confirms that usual-type ECAs are the most common type worldwide and that mucinous carcinomas comprise a mixture of HPVA and NHPVA, with gastric-type carcinoma being the major NHPVA type. Endometrioid and serous carcinomas of the endocervix are extraordinarily rare. Should clinical outcomes and genomic studies continue to support these findings, we recommend replacement of the World Health Organization 2014 criteria with the IECC 2017.
Zhonghua Bing Li Xue Za Zhi.
Zhao YH, Liu HG.
PMID: 27646894 | DOI: 10.3760/cma.j.issn.0529-5807.2016.09.010.
OBJECTIVE:
To study the clinicopathologic features, immunophenotype, differential diagnosis and prognosis of non-keratinizing carcinoma of nasal cavity and paranasal sinus.
METHODS:
Four hundred and forty-one cases of squamous cell carcinoma of the nasal cavity and sinuses diagnosed in Beijing Tongren Hospital from January 2008 to August 2015 were included. Twenty-six cases of non-keratinizing carcinomas were selected. The histopathologic features and the clinicopathologic data of these twenty-six cases were retrospectively analyzed. Immunohistochemistry (two-step EnVision method) was done to evaluate the expression of CK, vimentin, CK5/6, CK7, CK8/18, p16, p53, Ki-67 etc. In situ hybridization was used to detect Epstein-Barr virus mRNA(EBER), and flow-through hybridization was used to evaluate the presence of human papilloma virus (HPV). One of the cases which HPV is positive was detected by HPV in situ hybridization and RNAscope technology.
RESULTS:
The mean age for the twenty-six patients (16 males, 10 females) was 51.2 years (range 22 to 79 years). Three patients had a history of inverted papilloma.Microscopically the tumors showed invasive papillary and inverted growth, and formed solid cell nests with different sizes. It was similar to papillary carcinoma of the urinary tract: the nuclei of the tumor were rounded and the nucleolus are clear. Three cases displayed transition between normal epithelium to neoplastic cells; in two cases (2/26), some tumor cells were spindle shaped. Twenty cases (20/20) were strongly positive for CK, p63; 17 cases (17/20) were strongly positive for CK5/6 and three cases (3/20) were focally positive. Sixteen cases were strongly positive for CK8/18 and three cases (3/20) were focally positive and one case was negative. Seven cases (7/20) were strongly positive for CK7 and 13 cases (13/20) were negative. Two cases (2/20) were focally positive for vimentin and eighteen (18/20) cases were negative. One case (1/20) was strongly positive for p16 and nineteen cases (19/20) were negative. Nineteen cases (19/20) were positive for p53 and one case (1/20) was negative. Ki-67 index was >50% in 11 cases. Twenty cases (20/20) were negative for AFP, NUT, S-100 protein, HMB45 and Melan A. One case was positive for HPV (6, 11, 16, 18), as detected by in situ hybridization. The HPV18 mRNA was detected by RNAscope technique. In situ hybridization were negative in all twenty cases. The mean follow-up time of the patients in this group was less than 5 years, and the prognosis needs further observation.
CONCLUSIONS:
Non-keratinizing squamous cell carcinoma is a rare neoplasm with distinct morphological characteristics. Its diagnosis is primarily based on the site of lesions and the histological features.Immunohistochemistry staining can aid the diagnosis and differential diagnoses. The tumor may originate from the epithelium of nasal cavity and sinus. This disease has no relation with HPV and EBV infection, and the treatment is primarily surgical excision combined with postoperative radiotherapy.
The American journal of surgical pathology
Kuga, R;Yamamoto, H;Jiromaru, R;Hongo, T;Yasumatsu, R;Matsuo, M;Hashimoto, K;Taniguchi, M;Nakagawa, T;Oda, Y;
PMID: 37357948 | DOI: 10.1097/PAS.0000000000002086
The prevalence and prognostic significance of high-risk human papillomavirus (HR-HPV) have been well-established in oropharyngeal squamous cell carcinoma (OPSCC), but not in hypopharyngeal squamous cell carcinoma (HPSCC) or laryngeal squamous cell carcinoma (LSCC). Moreover, HR-HPV infection in squamous cell carcinoma with multisite involvement has not been examined. To clarify these issues, we retrospectively collected 480 invasive tumors from 467 patients with HPSCC, LSCC, or OPSCC, and comprehensively analyzed the detailed tumor localization, transcriptionally active HR-HPV infection by messenger RNA in situ hybridization, and immunohistochemical staining for p16 and Rb. HR-HPV infection was observed in 115/480 tumors (24%). Human papillomavirus (HPV)-positive cases were closely related with p16 positivity and the partial loss pattern of Rb. HR-HPV was detected in 104 of 161 tumors (64.6%) in the pure OPSCC group and only 1 of 253 tumors (0.4%) in the pure HP/LSCC group; the positive case occurred in the vocal cords. In the multisite-involving combined-type squamous cell carcinoma group, HPV infection was observed in 10/40 (25%) cases, and the 10 HPV-positive cases had OPSCC extending to the larynx or hypopharynx. Among high T-stage (T3/T4) cases of pure OPSCC, HPV-positive cases showed a better prognosis (P=0.0144), whereas the HPV-positive combined OPSCC group did not show a better prognosis (P=0.9428), as compared with HPV-negative counterpart. The results suggest that HR-HPV infection in pure HPSCC and LSCC may be extremely rare. HR-HPV infection seems to be present in a substantial proportion of patients with combined OPSCC and HPSCC/LSCC, but it may not improve prognosis at such advanced disease stages. Confirmation of these points awaits future studies with larger cohorts.
Arch Pathol Lab Med. 2014 Sep;138(9):1193-202.
Patel KR, Liu TC, Vaccharajani N, Chapman WC, Brunt EM.
PMID: 25171414 | DOI: 10.1016/j.cell.2014.07.001
Context.-The World Health Organization has recently recognized lymphoepithelioma-like carcinoma, or inflammatory hepatocellular carcinoma, as a variant of hepatocellular carcinoma. Objective.-To identify and characterize the inflammatory hepatocellular carcinomas in our institution from 1988 to the present. Design.-All cases of hepatocellular carcinoma in our institution from 1988 to the present were reviewed and reclassified as lymphoepithelioma-like carcinoma and were studied in comparison to appropriately matched controls. Results.-Among the 8 cases of lymphoepithelioma-like carcinoma identified, the male to female ratio was 1:3, the mean age was 68.5 years (range, 57-78 years), and all of the cases were seen in noncirrhotic livers. The average numbers of lymphocytes were significantly higher in the cases than in the controls. T cells were predominant, with a uniform distribution of CD4 and CD8 positive cells. Cholangiolar differentiation was seen by K19 positivity as focal in 1 case and diffuse in 2 cases. In situ hybridization for Epstein-Barr virus was negative in all of the cases. Diffuse overexpression of p16 (>75% of cells) was seen in 2 cases, both of which were negative for the presence of transcriptionally active human papilloma virus by in situ hybridization. In our series, 3 of 8 cases (37.5%) showed local recurrence, which was similar to the controls (6 of 18; 33%), P > .99. Although the rate of distant metastases was lower among the cases (12.5%) than the controls (22.2%), the difference was not statistically significant (P > .99). Conclusion.-We present the first series of 8 cases of lymphoepithelioma-like carcinoma of the liver occurring in patients without cirrhosis and with a female preponderance and the absence of Epstein-Barr virus. Although clinical outcomes were similar to those of controls in our small series, additional data may be required for confirmation.
Goyal A, Wang Z, Przybycin CG, Yang B.
PMID: 26352551 | DOI: 10.1097/PGP.0000000000000221.
Our understanding of adenoid basal tumors of the cervix has evolved over time. Most of the proliferations referred to as adenoid basal carcinoma have a clinically benign course-leading some to suggest the term "adenoid basal epithelioma." However, rarely, these may be associated with invasive carcinomas. These tumors have been etiologically linked with high-risk human papillomavirus (HR-HPV) infection. Here, we investigate the use of p16 immunohistochemistry and HR-HPV RNA in situ hybridization (ISH) in the classification of adenoid basal tumors of the cervix. Seventeen cases of adenoid basal tumors of the cervix were included. The patients' age ranged from 19 to 79 yr (average, 59 yr). p16 immunostain was performed on all cases and RNA ISH was performed in 4 cases with available formalin-fixed paraffin-embedded tissue. There were 11 low-grade tumors, 5 frankly invasive carcinomas, and 1 with histologic features that were intermediate between the former 2 categories. p16 immunostain was negative or showed patchy cytoplasmic staining in the low-grade tumors and was strongly and diffusely positive in the invasive carcinomas. HR-HPV RNA ISH was negative in the 3 low-grade tumors and was positive in 1 case of invasive carcinoma including the adenoid basal component. Distinct p16 immunostaining and HR-HPV RNA ISH patterns exist between low-grade adenoid basal tumors and invasive adenoid basal carcinomas. Our study indicates that p16 immunostaining and HR-HPV RNA ISH can be employed as useful ancillary tools in differentiating between noninvasive and invasive adenoid basal tumors along with careful histopathologic evaluation.
Tetzlaff MT, Curry JL, Ning J, Sagiv O, Kandl T, Peng B, Bell D, Routbort MJ, Hudgens CW, Ivan D, Kim T, Chen K, Eterovic AK, Shaw KRM, Prieto VG, Yemelyanova A, Esmaeli B.
PMID: 30420449 | DOI: 10.1158/1078-0432.CCR-18-1688
Abstract
PURPOSE:
Ocular adnexal (OA) sebaceous carcinoma is an aggressive malignancy of the eyelid and ocular adnexa that frequently recurs and metastasizes, and effective therapies beyond surgical excision are lacking. There remains a critical need to define the molecular-genetic drivers of the disease to understand carcinomagenesis and progression and to devise novel treatment strategies.
EXPERIMENTAL DESIGN:
We present next generation sequencing of a targeted panel of cancer-associated genes in 42 and whole transcriptome RNA sequencing from 8 OA sebaceous carcinomas from 29 patients.
RESULTS:
We delineate two potentially distinct molecular-genetic subtypes of OA sebaceous carcinoma. The first is defined by somatic mutations impacting TP53 and/or RB1 (20/29 [70%] patients, including 10 patients whose primary tumors contained co-existing TP53 and RB1 mutations) with frequent concomitant mutations affecting NOTCH genes. These tumors arise in older patients and show frequent local recurrence. The second subtype (9/29 [31%] patients) lacks mutations affecting TP53, RB1, or NOTCH family members, but in 44% (4/9) of these tumors, RNA sequencing and in situ hybridization studies confirm transcriptionally active high-risk human papillomavirus (HPV). These tumors arise in younger patients and have not shown local recurrence.
CONCLUSIONS:
Together, our findings establish a potential molecular-genetic framework by which to understand the development and progression of OA sebaceous carcinoma and provide key molecular-genetic insights to direct the design of novel therapeutic interventions.
Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc
Novack, R;Zhang, L;Hoang, LN;Kadhim, M;Ng, TL;Poh, CF;Kevin Ko, YC;
PMID: 36906072 | DOI: 10.1016/j.modpat.2023.100153
The diagnosis of oral epithelial dysplasia is based on the degree of architectural and cytologic atypia in the squamous epithelium. The conventional grading system of mild, moderate, and severe dysplasia is considered by many the gold standard in predicting the risk of malignant transformation. Unfortunately, some low-grade lesions, with or without dysplasia, progress to squamous cell carcinoma (SCC) in short periods. As a result, we are proposing a new approach to characterize oral dysplastic lesions that will help identify lesions at high risk for malignant transformation. We included a total of 203 cases of oral epithelial dysplasia, proliferative verrucous leukoplakia, lichenoid, and commonly observed mucosal reactive lesions to evaluate their p53 immunohistochemical (IHC) staining patterns. We identified 4 wild-type patterns, including scattered basal, patchy basal/parabasal, null-like/basal sparing, mid-epithelial/basal sparing, and 3 abnormal p53 patterns, including overexpression basal/parabasal only, overexpression basal/parabasal to diffuse, and null. All cases of lichenoid and reactive lesions exhibited scattered basal or patchy basal/parabasal patterns, whereas human papillomavirus-associated oral epithelial dysplasia demonstrated null-like/basal sparing or mid-epithelial/basal sparing patterns. Of the oral epithelial dysplasia cases, 42.5% (51/120) demonstrated an abnormal p53 IHC pattern. p53 abnormal oral epithelial dysplasia was significantly more likely to progress to invasive SCC when compared with p53 wild-type oral epithelial dysplasia (21.6% vs 0%, P < .0001). Furthermore, p53 abnormal oral epithelial dysplasia was more likely to have dyskeratosis and/or acantholysis (98.0% vs 43.5%, P < .0001). We propose the term p53 abnormal oral epithelial dysplasia to highlight the importance of utilizing p53 IHC stain to recognize lesions that are at high risk of progression to invasive disease, irrespective of the histologic grade, and propose that these lesions should not be graded using the conventional grading system to avoid delayed management.
Lagarde-Lenon, MS;Aron, M;
PMID: 36894368 | DOI: 10.1016/j.humpath.2023.02.011
Primary female urethral carcinoma (PUC-F) accounts for less than 1% of all genitourinary malignancies and comprises a histologically diverse group of tumors that are usually associated with poor prognosis. The carcinomas documented at this site include adenocarcinoma (clear cell adenocarcinoma, columnar cell carcinoma, and Skene gland adenocarcinoma), urothelial carcinoma (UCa), and squamous cell carcinoma (SCC). Recent studies have shown adenocarcinomas to be the most common type of primary urethral carcinoma in females. As most of the urethral carcinomas morphologically resemble carcinomas arising from surrounding pelvic organs or metastases, these should be ruled out before making the diagnosis of PUC-F. These tumors are currently staged according to the 8th edition of the American Joint Committee on Cancer (AJCC) staging system. However, the AJCC system has limitations, including the staging of tumors involving the anterior wall of the urethra. Staging systems like the recently proposed histology-based female urethral carcinoma staging system (UCS) takes into account the unique histological landmarks of the female urethra to better stratify pT2 and pT3 tumors into prognostic groups, that correlate with clinical outcomes including recurrence rates, disease-specific survival and overall survival. Further larger multi-institutional cohorts are however required to validate the results of this staging system. There is very limited information regarding the molecular profiling of PUC-F. Thirty-one percent of clear cell adenocarcinomas have been reported to show PIK3CA alterations, whereas 15% of adenocarcinomas show PTEN mutations. Higher tumor mutational burden and PD-L1 staining have been reported in UCa and SCC. Although multimodality treatment is usually recommended in locally advanced and metastatic disease, the role of immunotherapy and targeted therapy is promising in select PUC-F cases.
Liao, X;Xia, X;Su, W;Yan, H;Ma, Y;Xu, L;Luo, H;Liu, W;Yin, D;Zhang, WH;Chen, HN;Deng, Y;Ren, Z;Yu, Z;Liao, F;Chen, K;Cao, M;Zhang, Y;Zhang, W;Wang, W;Zhao, JN;Xu, H;Shu, Y;
PMID: 35151492 | DOI: 10.1016/j.ygyno.2022.01.036
Gastric-type cervical adenocarcinoma (GCA) is a rare and aggressive type of endocervical adenocarcinoma (ECA) with distinct histopathologic features and unfavorable treatment outcomes, but no genomic prognostic factor has been revealed. We aimed to systematically investigate the somatic alterations of GCA at genome-wide level and evaluate their prognostic value.We performed whole-exome sequencing (WES) on 25 pairs of tumor and matched normal samples to characterize the genomic features of Chinese patients with GCA and investigated their relations to histopathological characterizations and prognosis. The prognostic value of the genomic alterations was evaluated in a total of 58 GCA patients.Mutations were commonly observed in reported GCA-related driver genes, including TP53 (32%), CDKN2A (20%), SKT11 (20%), BRCA2 (12%), SMAD4 (12%), and ERBB2 (12%). Recurrent novel trunk mutations were also observed in PBRM1 (12%), FRMPD4 (12%), and NOP2 (8%) with high variant allele frequency. Moreover, enrichment of the APOBEC signature was attributed to frequent gain of somatic copy number alteration (SCNA) of APOBEC3B (20%), which perfectly matched the nuclear-positive staining of APOBEC3B through immunohistochemistry. In contrast, APOBEC3B alteration was absent in patients with conventional type of ECA (N = 52). Notably, positive APOBEC3B was consistently enriched in patients with favorable prognosis in both the discovery cohort and an additional 33 GCA patients, thus indicating a significant association with lower relapse risk of GCA independent of cancer stage (P = 0.02).Our results can aid understanding of the molecular basis of GCA in the Chinese population by providing genomic profiles and highlighting the potential prognostic value of APOBEC3B for GCA through routine clinical IHC.
Genetic and transcriptomic analyses in a rare case of HPV-related oropharyngeal squamous cell carcinoma combined with small cell carcinoma
Cold Spring Harbor molecular case studies
Sato, K;Nishiyama, K;Taguchi, K;Jiromaru, R;Yamamoto, H;Matsunaga, A;Nagata, R;Rikimaru, F;Toh, S;Higaki, Y;Oda, S;Nakagawa, T;Masuda, M;
PMID: 34462366 | DOI: 10.1101/mcs.a006102
Human papillomavirus (HPV)-related oropharyngeal small cell carcinoma (OPSmCC) is a rare malignancy with aggressive behavior, whereas HPV-related oropharyngeal squamous cell carcinoma (OPSqCC) displays a favorable prognosis. Notably, these two malignancies occasionally arise in an identical tumor. In this case study, we explored the molecular characteristics that distinguishes these two carcinomas employing a rare case of HPV-related oropharyngeal carcinoma (OPC) with the combined histology of SmCC and SqCC. Immunohistochemical analysis and HPV-RNA in situ hybridization (ISH) suggested that both SmCC and SqCC were HPV-related malignancies. Targeted exome sequencing revealed that SmCC and SqCC had no significant difference in mutations of known driver genes. In contrast, RNA sequencing followed by bioinformatic analyses suggested that aberrant transcriptional programs may be responsible for the neuroendocrine differentiation of HPV-related OPC. Compared to SqCC, genes upregulated in SmCC were functionally enriched in inflammatory and immune responses (e.g., arachidonic acid metabolism). We then developed a SmCC-like gene module (top 10 upregulated genes) and found that OPC patients with high module activity showed poor prognosis in The Cancer Genome Atlas (TCGA) and GSE65858 cohort. Gene set enrichment analysis of the SmCC-like gene module suggested its link to MYC proto-oncogene in the TCGA dataset. Taken together, these findings suggest that the SmCC-like gene module may contribute to acquisition of aggressive phenotypes and tumor heterogeneity of HPV-related OPC. The present case study is the first report of genetic and transcriptomic aberrations in HPV-related OPSmCC combined with SqCC.Cold Spring Harbor Laboratory Press.