Bilateral sinonasal inverted papillomas originating from both sides of the frontal sinus and the left lamina papyracea: A case report.

RATIONALE: The present investigation documented a case of bilateral sinonasal inverted papilloma (SNIP) that arose from both sides of the frontal sinus and ethmoid sinus. The occurrence of bilateral involvement of the nasal cavities and frontal sinus is rather infrequent. PATIENT CONCERNS: Informed consent was obtained from the patient. DIAGNOSIS: Bilateral SNIP. INTERVENTIONS: The tumor was completely removed by Draf III endoscopic resection complemented by an external eyebrow arch approach, and the postoperative recovery was uneventful. OUTCOMES: The purpose of this paper is to present a comprehensive reference for the management of bilateral SNIP that affects the frontal sinuses. LESSONS: This study addresses the staging and surgical management of bilateral SNIP, along with a review of the factors contributing to its recurrence. The recommended treatment method involves applying the Draf III technique combined with an external nasal approach.

Quantitative differentiation of non-invasive bladder urothelial carcinoma and inverted papilloma based on CT urography.

PURPOSE: To investigate the value of CT urography (CTU) indicators in the quantitative differential diagnosis of bladder urothelial carcinoma (BUC) and inverted papilloma of the bladder (IPB). MATERIAL AND METHODS: The clinical and preoperative CTU imaging data of continuous 103 patients with histologically confirmed BUC or IPB were retrospectively analyzed. The imaging data included 6 qualitative indicators and 7 quantitative measures. The recorded clinical information and imaging features were subjected to univariate and multivariate logistic regression analysis to find independent risk factors for BUC, and a combined multi-indicator prediction model was constructed, and the prediction model was visualized using nomogram. ROC curve analysis was used to calculate and compare the predictive efficacy of independent risk factors and nomogram. RESULTS: Junction smoothness, maximum longitudinal diameter, tumor-wall interface and arterial reinforcement rate were independent risk factors for distinguishing BUC from IPB. The AUC of the combined model was 0.934 (sensitivity = 0.808, specificity = 0.920, accuracy = 0.835), and its diagnostic efficiency was higher than that of junction smoothness (AUC=0.667, sensitivity = 0.654, specificity = 0.680, accuracy = 0.660), maximum longitudinal diameter (AUC=0.757, sensitivity = 0.833, specificity = 0.604, accuracy = 0.786), tumor-wall interface (AUC=0.888, sensitivity = 0.755, specificity = 0.808, accuracy = 0.816) and Arterial reinforcement rate (AUC=0.786, sensitivity = 0.936, specificity = 0.640, accuracy = 0.864). CONCLUSION: Above qualitative and quantitative indicators based on CTU and the combination of them may be helpful to the differential diagnosis of BUC and IPB, thus better assisting in clinical decision-making. KEY POINTS: 1. Bladder urothelial carcinoma (BUC) and inverted papilloma of the bladder (IPB) exhibit similar clinical symptoms and imaging presentations. 2. The diagnostic value of CT urography (CTU) in distinguishing between BUC and IPB has not been documented. 3. BUC and IPB differ in lesion size, growth pattern and blood supply. 4. The diagnostic efficiency is optimized by integrating multiple independent risk factors into the prediction model.

[Inverted papilloma of the nose and paranasal sinuses : Diagnosis, treatment, and malignant transformation]. / Invertiertes Papillom der Nase und Nasennebenhöhlen : Diagnostik, Therapie und maligne Transformation.

Inverted papilloma (IP) are benign tumors that show a locally aggressive behavior, a high rate of recurrence, and a potential for malignant transformation. Specific radiological signs such as hyperostosis at the origin of the IP and convoluted cerebriform patterns, as well as the typical endoscopic aspect, can lead to diagnosis and enable preoperative planning of surgical access and the extent of surgery. Endonasal endoscopic techniques are considered the gold standard and the introduction of extended surgical techniques such as the prelacrimal approach, frontal drillout, or orbital transposition facilitate complete subperiosteal resection with preservation of important physiological structures. There is a risk of synchronous and metachronous squamous cell carcinomas (IP-SCC). Research focuses on radiological criteria to differentiate benign IP from IP-SCC, genetic and epigenetic factors in the process of malignant transformation, and estimation of the risk of IP progressing to IP-SCC.

Epithelial Tight Junction Anomalies in Nasal Inverted Papilloma.

OBJECTIVES: As a critical component of the epithelial barrier, tight junctions (TJs) are essential in nasal mucosa against pathogen invasion. However, the function of TJs has rarely been reported in nasal inverted papilloma (NIP). This study aims to investigate the potential factors of TJs' abnormality in NIP. METHODS: We assessed the expression of ZO-1, occludin, claudin-1, claudin-3, and claudin-7 in healthy controls and NIP by real-time quantitative polymerase chain reaction and immunofluorescent staining. The correlation between TJs expression and neutrophil count, TH 1/TH 2/TH 17 and regulatory T cell biomarkers, and the proportion of nasal epithelial cells was investigated. RESULTS: Upregulation of ZO-1, occludin, claudin-1, and claudin-7, along with downregulation of claudin-3, was found in NIP compared to control (all p < 0.05). An abnormal proportion with a lower number of ciliated cells (control vs. NIP: 37.60 vs. 8.67) and goblet cells (12.52 vs. 0.33) together with a higher number of basal cells (45.58 vs. 124.00) in NIP. Meanwhile, claudin-3 was positively correlated with ciliated and goblet cells (all p < 0.01). Additionally, neutrophils were excessively infiltrated in NIP, negatively correlated with ZO-1, but positively with claudin-3 (all p < 0.05). Furthermore, FOXP3, IL-10, TGF-ß1, IL-5, IL-13, and IL-22 levels were induced in NIP (all p < 0.01). Occludin level was negatively correlated with IL-10, IL-5, IL-13, and IL-22, whereas ZO-1 was positively with TGF-ß1 (all p < 0.05). CONCLUSION: Nasal epithelial barrier dysfunction with TJs anomalies is commonly associated with abnormal proliferation and differentiation of epithelial cells and imbalance of immune and inflammatory patterns in NIP. LEVEL OF EVIDENCE: NA Laryngoscope, 134:552-561, 2024.

Online health information on sinonasal inverted papillomas: An assessment on readability and quality.

BACKGROUND/OBJECTIVES: Sinonasal inverted papilloma (IP) is a rare but serious diagnosis, with a paucity of patient-centred information regarding this condition. As more patients are seeking healthcare information online, the quality and comprehensibility of this information becomes ever more important. The aim of the study was to investigate the readability and quality of websites on inverted papilloma. METHODS: The term IP and seven of its synonyms were inputted into the three of the most commonly used search engines in the English-speaking world (Google, Yahoo and Bing). The first 20 results returned for each search term were then screened with our exclusion criteria. The remaining websites were assessed for their readability using the using the Flesch Reading Ease Score (FRES) and average grade level (AGL). Quality was assessed using the DISCERN questionnaire. RESULTS: Of the 480 websites returned using our search strategy, 410 were excluded using our screening criteria. Removal of duplicates from the remaining 70 websites left 14 for inclusion in the final analysis. The mean FRES score of the remaining websites was 30.5 ± 10 and the mean AGL was 15.2 ± 1.1, corresponding to a reading age of a 21-year-old. The median DISCERN score was 33.5 (30.5-36.5), a score which falls within the 'poor quality' range. CONCLUSION: The readability and quality of online patient information on IP is far below the expected standard. Healthcare providers have a responsibility to direct patients to appropriate sources of information or consider producing new material should a lack of appropriate sources exist.

A Large Pleomorphic Adenoma in Nasal Cavity Misdiagnosed as Inverted Papilloma.

Pleomorphic adenoma (PA) is a benign tumor characterized by slow-growing mixed tumors in the craniofacial area. It is relatively common in salivary glands; however, PA of the nasal cavity, which arises in the minor salivary glands, is rare. We present the case of a large PA in the nasal cavity of an adult immunocompetent woman with nasal obstruction and intermittent epistaxis. Based on preoperative radiologic examinations, she was misdiagnosed with an inverted papilloma. Endoscopic resection was performed under general anesthesia. Pathologically, the patient was confirmed to have PA, which has great cellularity and few stromal components. No complications or recurrences during the 1-year follow-up period were observed.

Claw bed inverted squamous papilloma associated with canine papillomavirus type 2 in a dog.

A claw bed inverted squamous papilloma (ISP) presented clinically as a swollen digit in a dog. Canine papillomavirus (CPV) type 2 was amplified by PCR and localised to the papilloma's epidermis using in situ hybridisation. This is the first report demonstrating a claw bed ISP caused by CPV.

Un papillome squameux inversé de la matrice unguéale est décrit cliniquement comme un gonflement du doigt chez un chien. Le papillomavirus canin (CPV) de type 2 a été amplifié par PCR et localisé dans l'épiderme du papillome par hybridation in situ. Il s'agit du premier rapport faisant état d'un papillome squameux inversé de la matrice unguéale par le CPV.

Um caso de papiloma escamoso invertido no leito ungueal em um cão apresentando aumento de volume em um dígito. O vírus do papiloma canino (CVP) Tipo 2 foi amplificado por PCR e localizado na epiderme do papiloma utilizando hibridização in situ. Este foi o primeiro relato demonstrando um papiloma escamoso invertido causado por CPV.

Un papiloma escamoso invertido del lecho ungueal se presentó clínicamente como un dedo hinchado en un perro. Se amplificó mediante PCR genoma del virus papiloma canino tipo 2 (CPV) y se localizó en la epidermis el papiloma mediante hibridación in situ. Este es el primer reporte de caso que demuestra la existencia de un papiloma escamoso invertido del lecho ungueal causado por CPV.

RAS Family Gene Mutations, Clinicopathological Features, and Spread Patterns of Inverted Urothelial Papilloma of the Bladder.

Inverted urothelial papilloma (IUP) is a benign neoplasm characterized by a downgrowth of the urothelium beneath the surface of morphologically normal urothelial cells; however, the molecular features of IUP and their association with clinicopathological characteristics are unclear. In this study, we aimed to investigate the mutational landscape, clinicopathological features, genotype-phenotype associations, and spread patterns of IUP. We performed targeted next-generation sequencing of 39 consecutive IUP cases, the largest series investigated to date, and identified oncogenic driver mutations in RAS family genes in 34 cases (87%). HRAS mutations were the most prevalent (28 cases), which included Q61R (15 cases), followed by KRAS (5 cases) and NRAS (1 case) mutations. Characteristic mutations observed in urothelial carcinoma, including those in FGFR3 , TP53 , or the TERT promoter, were absent. HRAS -mutated IUPs were associated with a history of smoking ( P = 0.017) and streaming morphology ( P < 0.001), corresponding to the trabecular subtype. In contrast, all KRAS -mutated IUPs occurred in never-smoking patients ( P = 0.001) and showed cystic changes in morphology ( P = 0.005), corresponding to the glandular subtype. RAS Q61R immunohistochemistry visually revealed the neoplastic nature of the overlying cells and distinct spread patterns of IUP cells within the surface, including pseudoinfiltrative spread. No recurrence or carcinoma development was observed in any of the IUP cases during the follow-up period. Thus, we confirmed the importance of RAS pathway activation in IUP pathogenesis, an association between RAS family gene mutations and IUP subtypes, and the spread patterns of IUP cells within the surface.

Multiparametric MRI-based radiomics nomogram for predicting malignant transformation of sinonasal inverted papilloma.

AIM: To investigate the feasibility of a radiomics nomogram model for predicting malignant transformation in sinonasal inverted papilloma (IP) based on radiomic signature and clinical risk factors. MATERIALS AND METHODS: This single institutional retrospective review included a total of 143 patients with IP and 75 patients with IP with malignant transformation to squamous cell carcinoma (IP-SCC). All patients underwent surgical pathology and had preoperative magnetic resonance imaging (MRI) and computed tomography (CT) sinus studies between June 2014 and February 2022. Radiomics features were extracted from contrast-enhanced T1-weighted images (CE-T1WI), T2-weighted images (T2WI), and apparent diffusion coefficient (ADC) maps. The least absolute shrinkage and selection operator (LASSO) were performed to select the features extracted from the sequences mentioned above. Independent clinical risk factors were identified by multivariate logistic regression analysis. Radiomics nomogram was constructed by incorporating independent clinical risk factors and radiomics signature. Based on discrimination and calibration, the diagnostic performance of the nomogram was evaluated. RESULTS: Twelve radiomics features were selected to develop the radiomics model with an area under the curve (AUC) of 0.987 and 0.989, respectively. Epistaxis (p=0.011), T2 equal signal (p=0.003), extranasal invasion (p<0.001), and loss of convoluted cerebriform pattern (p=0.002) were identified as independent clinical predictors. The radiomics nomogram model showed excellent calibration and discrimination (AUC: 0.993, 95% confidence interval [CI]: 0.985-1.00 and 0.990, 95% CI: 0.974-1.00) in the training and validation sets, respectively. CONCLUSION: The nomogram that the combined radiomics signature and clinical risk factors showed a satisfactory ability to predict IP-SCC.

Nasal obstruction in a 14 year old girl caused by a huge middle turbinate mucocele appearing radiologically as an inverted papilloma.

Introduction: We present a case of a fourteen year old girl who presented with a large intra-nasal mass to the ENT team at a district general hospital in the UK. Presentation of case: The girl presented predominantly with nasal obstruction and some symptoms of allergic rhinitis. Imaging revealed a large lesion abutting the skull base and causing bony remodelling with marked septal deviation. Based both on CT and MRI imaging, the reporting (non-head and neck) radiologist suggested inverted papilloma as a differential diagnosis. Intra-operative exploration in fact revealed a very large left middle turbinate mucocele extending to the left frontal sinus. The mass was excised endoscopically without complications. Discussion: Although concha bullosa of the middle turbinate of the nose are common, development of a mucocele within them is far less common and for such a mucocele to develop to this size in a child is extremely rare. The egg shell lining of the lesion can be a tell-tale sign of their aetiology when taken alongside other radiological factors. This case highlights challenges in radiological diagnosis of intra-nasal masses in children, which can lead to delays and increased anxiety. Conclusion: When assessing nasal masses in children it is important to keep a wide differential due to the challenges of diagnosis. A close conversation should be had with local head and neck radiologists and, of course, where there is a unilateral nasal mass tissue sampling is essential and may be taken as part of a full excision where clinically indicated.

Human papillomavirus expression in relation to biological behavior, Ki-67 proliferative marker, and P53 prognostic marker in Schneiderian papilloma.

Various malignant and benign tumors can arise in the sinonasal cavity, including inverted papilloma (IP), a benign neoplasm with unique clinical characteristics. However, the mechanisms involved in the recurrence, occurrence, and malignant transformation of IP remain debatable. This study aimed to investigate the impact of human papillomavirus (HPV) infections on IP by comparing the number of infections in cases with epithelial tissue dysplasia and explore the predictive role of proliferative and prognostic markers in dysplasia. Tissue blocks from 35 cases of sinonasal papilloma, collected between 2015 and 2021 from the laboratory archives of the Medical City of Ghazi Al-Hererri Hospital in Baghdad, Iraq, were immunohistochemically stained with monoclonal antibodies (mAbs) to detect Ki-67 and p53. A quantitative immunohistochemical analysis was conducted to analyze the results. Polymerase chain reaction (PCR) was performed to detect HPV genotypes 16/18 and 6/11 in the tissues. There was an insignificant increase in Ki-67 and p53 expression in inverted papillomas with dysplasia. HPV11 was the most prevalent genotype in 34.3% of the patients, followed by HPV16 and HPV18 in 31.4% of the patients for each virus. The least common virus detected was human papillomavirus 6 (8.6%), which did not show any significant association with the degree of dysplasia. Viral detection proliferation and apoptosis had no impact on tumor dysplasia amongst all the patients, showing no relationship with the evaluated cases.

An in vitro model and the underlying pathways of sinonasal inverted papilloma development.

Recently, the specific association between Sinonasal inverted papilloma (SIP) and EGFR exon 20 mutations has been reported. To investigate the link between specific EGFR mutations and SIP development, we established organotypic raft culture system using nasal polyp-derived immortalized NP2 (iNP2) cells expressing EGFR exon 20 mutants or an exon 19 mutant, and SIP-derived iIP4 cells harboring P772_H773insPYNP mutation. In the raft culture, iIP4 cells showed the inverted growth pattern characteristic to SIP. Interestingly, iNP2 cells expressing EGFR exon 20 duplication mutants, S768_D770dup and N771_H773dup, but not of EGFR exon 19 mutant, E746_A750del, showed the inverted growth pattern. Enhanced activation of the PI3K/AKT signaling pathway was observed in iNP2_S768_D770dup and iIP4 cells, while increased MAPK signaling was found in iNP2_N771_H773dup. Increased cell migration and invasion were found in all cells carrying EGFR mutations when compared to iNP2 cells, and this effect was inhibited by either PI3K or MEK inhibitor. Notably, iNP2 cells expressing the N771_H773dup mutant showed the highest migration and invasion abilities. These results suggest that specific mutations in EGFR exon 20 play a crucial role in SIP development, partially though hyper-activation of the PI3K/AKT and MAPK signaling pathways. This study presents the first in vitro model for SIP development, which could facilitate further investigations into SIP pathogenesis and preclinical studies for new therapeutic agents.

Preoperative prediction of sinonasal papilloma by artificial intelligence using nasal video endoscopy: a retrospective study.

Sinonasal inverted papilloma (IP) is at risk of recurrence and malignancy, and early diagnosis using nasal endoscopy is essential. We thus developed a diagnostic system using artificial intelligence (AI) to identify nasal sinus papilloma. Endoscopic surgery videos of 53 patients undergoing endoscopic sinus surgery were edited to train and evaluate deep neural network models and then a diagnostic system was developed. The correct diagnosis rate based on visual examination by otolaryngologists was also evaluated using the same videos and compared with that of the AI diagnostic system patients. Main outcomes evaluated included the percentage of correct diagnoses compared to AI diagnosis and the correct diagnosis rate for otolaryngologists based on years of practice experience. The diagnostic system had an area under the curve of 0.874, accuracy of 0.843, false positive rate of 0.124, and false negative rate of 0.191. The average correct diagnosis rate among otolaryngologists was 69.4%, indicating that the AI was highly accurate. Evidently, although the number of cases was small, a highly accurate diagnostic system was created. Future studies with larger samples to improve the accuracy of the system and expand the range of diseases that can be detected for more clinical applications are warranted.

[A case of sinonasal inverted papilloma with malignant transformation and distant metastasis: a 10-year follow-up report].

Sinonasal inverted papilloma（SNIP） is a kind of benign tumor originating from the nasal cavity and paranasal sinuses, accounting for 70% of papillomas. The incidence of the disease is more common in males, with an average age of 50-60 years. It is most likely to occur in unilateral maxillary sinus and ethmoid sinus, followed by sphenoid sinus and frontal sinus.It has the characteristics of local invasion, high recurrence rate and malignant tendency, and most malignant transformation into squamous cell carcinoma. Endoscopic nasal resection and appropriate adjuvant therapy can help to reduce the recurrence rate and inhibit further deterioration. We report the results of a 10-year follow-up of a SNIP patient, including the clinical manifestations, recurrence course and treatment plan during the 10 years. The patient underwent multiple nasal endoscopic surgeries, and had a recurrence of multiple focal attachment pattern, and finally had direct invasion and distant metastasis. Tumor recurrence and further deterioration persisted despite the use of a comprehensive treatment.

Extended sphenoidotomy combined with transpterygoid approach for sphenoidal sinus inverted papilloma.

PURPOSE: Inverted papilloma of the sphenoid sinus (IPSS) is a rare tumor with debated surgical management due to its proximity to vital structures. The aim of this manuscript is to highlight the role of a transpterygoid approach (TPA) and pedicle-orientated strategy in case of involvement of critical structures in IPSS and compare it with data from the literature. METHODS: Patients with primary IPSS between January 2000 and June 2021 were included. Pre-operative CT/MRI were analyzed to classify the pneumatization of the SS and predict the insertion point of the inverted papilloma. All patients were treated with a trans-sphenoidal approach which was combined with a TPA in case of lateral insertion point. A systematic search was also performed to summarize the available literature. RESULTS: Twenty-two patients were treated for IPSS. By CT, the SS was categorized with type III pneumatization in 72.8% of cases. Eleven patients (50%) were treated with a TPA with a statistical association with the insertion point on the SS lateral wall (p = 0.01), rather than a SS pneumatization (p = 0.63). The overall success was 95.5% after a mean follow-up of 35.9 months. For the literature, 26 publications were included on 97 patients and described a trans-sphenoidal approach with a success rate of 84.6% after a mean follow-up of 24.5 months. CONCLUSION: IPSS is generally treated with a sphenoidotomy approach, although in selected cases, a TPA should be preferred to expose the whole SS lateral wall though allowing a complete pedicled oriented resection of the tumor.

Validation of modular endoscopic medial maxillectomies for inverted papilloma of the maxillary sinus.

BACKGROUND: Treatment of inverted papilloma of the maxillary sinus (IPMS) has a lower success rate compared to other IPs. As such, its correct management generally needs trans-nasal endoscopic medial maxillectomy (EMMs) for adequate resection. The aim of this manuscript is to describe outcomes and major prognostic factors of a cohort of patients with IPMS who were treated with EMM. METHODOLOGY: In this multicentric study, patients affected with IPMS and treated with EMMs were included. The site of origin of the IPMS were studied as well as the type of EMM performed. The histological features (IP vs dysplasia), type of mucosal resection (total vs. pedicle oriented), and post-operative complications were analyzed. RESULTS: 310 patients were included (212 primary and 98 recurrent cases). After a mean follow-up of 45.4 months, 15 patients experienced recurrence (4.8%) due to the application of EMMs tailored to the surgical insertion point. Dysplasia was significantly associated with a higher risk of recurrence. The rates of early and late complications were 11.6% and 11.9%, respectively. CONCLUSIONS: IPMS resection via tailored EMM is associated with excellent disease control, thus excluding the systematic use of extended EMMs, which can however be justified in case of dysplastic IPMS given its significant impact on recurrence.

The implications of concomitant mucosal inflammation on clinical manifestations and outcomes of sinonasal inverted papilloma.

PURPOSE: This study examines the impact of concomitant mucosal inflammation on clinical manifestations and long-term outcomes of Inverted Papilloma (IP). METHODS: This retrospective cohort study was conducted in five tertiary medical centers. The included patients underwent an attachment-oriented surgical resection for IP with a minimum follow-up of 3 years. RESULTS: Of 185 patients with IP, 65 patients (35.1%) had synchronous mucosal inflammation with polypoid changes. The mean age was 56.7 years, and 69% were males. Most tumors originated from the maxillary sinus. Age, gender, Krouse stage, and tumor attachment site did not differ between the mucosal inflammation and IP-only groups. IP recurrence rate was twofold in the patients with mucosal inflammation (15.4% vs. 7.5%, p = 0.092). However, the difference was not significant, with a similar median time to recurrence between the two groups [15.5 (3-36) months vs. 16(6-96) months, p = 0.712]. In revision cases, IP recurred only in patients with mucosal inflammation (19% vs. 0%, p = 0.07). This group had a significantly worse 5-years recurrence-free survival than revision cases without mucosal inflammation (80.6% vs. 100%, p = 0.04). CONCLUSIONS: IP in the setting of mucosal inflammation might be associated with a higher recurrence rate, predominantly after revision surgery. Otolaryngologists should consider this during these patients' diagnosis, surgical planning, and follow-up.

Evaluation of high-risk human papillomavirus in sinonasal papillomas and squamous cell carcinomas.

The sinonasal tract is considered a second hotspot for human papillomavirus (HPV)-related tumors in the head and neck, with HPV being identified in up to 62% of squamous cell carcinomas (SCCs) and 38% of papillomas. There is limited data from geographical regions with low prevalence of high-risk (HR)-HPV on the association of HR-HPV in sinonasal neoplasms and on utility of p16 as a surrogate marker. p16 immunohistochemistry, HR-HPV mRNA ISH and quantitative real-time PCR (qPCR) were performed on a retrospective cohort of sinonasal papillomas and SCCs. KRAS mutation analysis was done in oncocytic papillomas. p16 positivity was present in 22/142 cases (15.5%) including eight inverted papillomas, one oncocytic papilloma (OP), and 13 SCC. Among these, mRNA ISH showed HR-HPV in the OP and two SCC, while another SCC was found to harbour HPV18 by qPCR. Two HPV-associated SCCs had foci of OP. mRNA ISH was negative in all p16 negative cases. p16 immunohistochemistry showed 68% concordance with mRNA ISH, and had sensitivity and negative predictive value of 100%; specificity was 67%, and positive predictive value was 14.3%. Association with HR-HPV in sinonasal papillomas and SCC is rare, and may be seen in cases demonstrating oncocytic morphology. p16 immunohistochemistry has low specificity and positive predictive value in low-prevalence populations; thus, reflex direct HR-HPV testing should be performed in p16 immunopositive cases. This two-step approach is viable in resource-limited settings, as the proportion of p16 positive cases is small.