xRead - Nasal Obstruction (September 2024) Full Articles

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ICAR SINONASAL TUMORS

Histopathologic diagnosis of sinonasal lymphoma and subtypes

IHC workup of the tissue in order to aid in diagnosis. While many lesions can be biopsied in the office with adequate topical anesthesia, biopsy under general anesthesia may be necessary if initial biopsies are nondiagnostic, in more vascular tumors, or if preferred by the patient. In both BCL and ENKTL, IHC, in situ hybridiza tion, and flow cytometry should be used to establish the diagnosis. 1811,1812 The pattern of positive and negative markers allows the pathologist to diagnose the lymphoma subtype in question. Desai et al. evaluated 25 cases of DLBCL, compared tumors arising from the nasopharynx and maxillary sinus, and noted that primary sinonasal DLBCL is histopathologically heterogeneous. 1813 NCCN guidelines recommend immunotyping for CD20 , CD3 , CD5 , CD10 , CD45 , BCL2 , BCL6 , Ki-67, IRF4/MUM1 , and MYC . 1810 In addition, NCCN recommends cell surface marker analysis by flow cytometry with peripheral blood and/or biopsy specimens: kappa/lambda ratio, CD45 , CD3 , CD5 , CD19 , CD10 , and CD20 . 1810 Carreras et al. performed a review of 29 patients with primary sinonasal DLBCL and with DNA microarray analysis found a characteristic genomic profile and that high RGS1 immunohistochemical expression is associated with poor OS. 1814 Murakami et al. investigated histological subtypes of lymphoma in patients newly diagnosed with malignant lymphoma in the human T-cell leukemia virus type 1 (HTLV-1) endemic area of Japan and found differing survival patterns among DLBCL based on presence of sinonasal tract involvement. 1815 In another analysis by Toda et al., germinal center and nongerminal center subtypes of DLBCL were compared and found to have no difference in OS. 1816 With regard to ENKTL, multiple authors have com mented on the difficulty of establishing a diagnosis due to the significant amount of tissue necrosis associated. 1790 It has been suggested that biopsies with small lympho cytic infiltrates, chronic inflammation, surface ulceration, and bone invasion should make the clinician suspicious for undiagnosed ENKTL in the right clinical context. 1817 Typical pathologic findings include angiocentricity and angiodestruction. 1818,1819 EBV in situ testing (EBER) and EBV systemic viral loads are a routine part of the workup given the etiologic role of the virus in ENKTL development. 1818,1820–1824 IHC panels should include TIA1, CD2, cytoplasmic CD3epsilon, CD5, and CD56 to establish the diagnosis. Flow cytometry targets include CD2, CD3, CD4, CD5, CD7, CD8, CD56, TCR alpha/beta, and TCR gamma/delta. 1774,1775,1825–1830 Some authors have advocated for testing β 2 microglobulin ( β 2M) in serum as they have noted worse survival with increasing levels of β 2M. 1831

Aggregate grade of evidence

C (Level 3: five studies; Level 4: 11 studies; five studies BCL, 11 studies ENKTL) Obtaining an accurate pathologic diagnosis is critical to determining the treatment regimen. Additional testing (e.g., IHC, ISH) helps elucidate the correct clinical diagnosis as determined by the pathologist. A potential delay in care or increased costs could result from immunohistochemical and other testing. Biopsy carries risks of pain and bleeding and rare risk of damage to intracranial or orbital contents (depending on the location of the lesion). There are no clinical studies examining the cost of obtaining a biopsy, laboratory testing, and resulting pathologic diagnosis in the workup of sinonasal lymphoma. Preponderance of benefits over harms. A head and neck and/or hematopathologist with experience in sinonasal lymphoma may benefit the treatment team. Additional studies are needed examining histopathological features predictive of outcomes in sinonasal lymphoma. diagnosis, particular cell type, is critical for guiding treatment for sinonasal lymphoma. Adjunctive laboratory and immunohistochemical testing, specifically flow cytometry and molecular diagnostics, may aid in obtaining diagnosis and may further characterize prognosis for the patient.

Benefit

Harm

Cost

Benefits–harm assessment

Value

Judgements

Policy level Recommendation. Intervention Determination of an accurate pathologic

E B-cell sinonasal lymphoma treatment 1 Role of chemotherapy BCLs and the most common subtype, DLBCL, are treated predominantly with chemotherapeutic regimens (Table XXVI.2). The most common regimen is CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) with the addition of rituximab (R-CHOP). 1810 There are no level 1 studies examining this chemotherapy regimen for