xRead - Nasal Obstruction (September 2024) Full Articles

20426984, 0, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/alr.23262, Wiley Online Library on [02/01/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License

143

ICAR SINONASAL TUMORS

E Role of orbital or skull base bony resection IP is a benign, locally aggressive neoplasm that usually arises in the nasal cavity. Due to documented recur rence rates up to 50% as well as 5%–20% risk of malig nant transformation, management of IP lesions can be challenging. 673–677 These lesions become especially prob lematic when juxtaposed with critical anatomical struc tures such as the orbit and skull base. Orbital invasion occurs in 2%–4% of IP cases. 335 Theori gin of these lesions can be difficult to determine in large lesions. They may arise from the nasolacrimal duct or paranasal sinuses. In either case, orbital involvement con fers an elevated risk of malignancy and recurrence. 678 In Elner et al., 100% (10/10) of lesions with orbital involve ment showed foci of malignancy on pathology. 679 Elevated risks of malignancy as compared with IP lesions not involving the orbit have been documented in smaller case series as well. 680–682 Prior studies have shown a 20%–80% recurrence rate for IP involving the orbit. 681,682 Given this increased risk of malignancy and recurrence, management of orbital IP lesions must be complete in order to prevent progression of disease in critical anatomic areas. In the largest series to date reporting management of the orbit in endoscopic sinonasal tumor surgery, the most common approaches included resection of lamina papyracea (LP), followed by DCR, and finally periorbita resection (when required for malignant pathology). In the management of IP, drilling of the hyperostotic focus or resection of the LP, in cases of extensive bony involve ment, allows effective treatment of disease at the orbital interface. 336,679–681,683 If bony involvement is not present, preservation of any residual lamina papyracea or periorbita must be considered to maintain the integrity of barriers to the orbital contents in the event of recurrence. 683 The dogma for management of IP lesions involving the orbit applies the transnasal approach and requires the balance of functional preservation and complete resection of the tumor (Table XVI.3). 683 CT has been reported to positively identify skull base attachment site in up to 74% of cases. In most cases, a focus of hyperostosis, or bony growth, can be determined. How ever, in some cases it is difficult to delineate attachment, even with CT imaging. 684 Once skull base involvement (discrete skull base attachment, not tumor that occupies the sinus and is just adjacent to the skull base with no involvement/invasion) is suspected, the surgeon must treat the attachment sites due to the risk of invasion. 673,685 Open excision has historically been preferred in this scenario, but endoscopic resection has emerged as the prefer able technique. 130,673,676,686–689 In Chiu et al., histopatho logic evidence demonstrated bony invasion in all IP

associated sinonasal carcinomas—in particular, the pres ence of mutually exclusive somatic EGFR mutations and low-risk HPV in these tumors—published literature asso ciating high-risk HPV with malignant conversion of IP should be evaluated with a degree of caution. Furthermore, the identification of low-risk HPV in a subset of IP associated sinonasal carcinomas is fascinating, as this goes against classic teaching in head and neck oncology regard ing the biologic trajectory of low-risk HPV lesions. This also highlights the need for further focused research in this area, specifically evaluating the mechanisms and conse quences of low-risk HPV infection in IP tumorigenesis and malignant conversion. Assessment of dysplasia and HPV in sinonasal papillomas

Aggregate grade of evidence

B (Level 2: seven studies; Level 3: 17 studies; Level 4: 22 studies) Proper histopathologic assessment is crucial to appropriately characterize IP grade and clinical behavior. The surgeon should consider assessment of EGFR and KRAS mutations and HPV in diagnostically challenging cases, particularly when there is concern for dysplasia or malignant transformation. There is potential negative impact on patient care when an incorrect pathologic diagnosis (e.g., understaging) is made. No studies currently discuss healthcare costs related to the diagnostic workup of IP and genomic or viral testing. Preponderance of benefits over harms.

Benefit

Harm

Cost

Benefits–harm assessment

Value Judgment Appropriate evaluation of tissue specimens allows for improved treatment

stratification. Given the potentially high risk of recurrence and morbidity from inappropriate treatment, a correct diagnosis is critical for sinonasal papillomas.

Policy level Recommendation. Intervention The surgeon should engage with the head

and neck pathologist to appropriately diagnose sinonasal papillomas and determine presence of dysplasia. EGFR mutations appear to be the dominant factor in IP development. Although low-risk HPV may be found in exophytic and inverted subtypes, there are limited data to support the involvement of high-risk HPV in sinonasal papillomas.