Head & Neck Pathology最新文献

Purpose: DEK::AFF2 fusion-associated squamous cell carcinoma (DEK::AFF2 SCC), also reported in the literature as low-grade papillary sinonasal (Schneiderian) carcinoma (LGPSC), is a rare, primarily bland-appearing, but locally aggressive neoplasm. Morphologically, these tumors can closely resemble sinonasal papilloma (SP), especially on small or limited biopsy, often leading to misdiagnosis. DEK::AFF2 SCC is devoid of the underlying mutually exclusive EGFR or KRAS driver mutations of SP, suggesting it may represent a distinct unique entity.

Methods: In this study, we conducted a retrospective search of "unusual" SP reported either as atypical, dysplastic, or suspicious for malignant transformation at our institution in the last 13 years (2010-2023), to identify potential cases of DEK::AFF2 SCC.

Results: Of the 201 SP cases during this time period, 30 "unusual" SP cases were identified. On morphologic review of these 30 cases, 6 were worrisome for DEK::AFF2 SCC and were selected for AFF2 immunohistochemical stain (IHC), of which 3 cases were positive. All 3 AFF2 IHC positive cases were also positive for DEK::AFF2 fusion by fluorescence in situ hybridization (FISH), thereby, confirming IHC results.

Conclusions: This study highlights that AFF2 IHC can be an invaluable surrogate marker to FISH in identifying DEK::AFF2 SCC in challenging cases to avoid misdiagnosis. Detailed clinical and pathologic data were collected to gain a better understanding of this emerging challenging entity. A literature review was performed to enrich our knowledge of DEK::AFF2 SCC.

One pathologist reflects upon her own medical journey and shares how that perspective is carried forward in her practice and her life.

An 81-year-old male patient presented with a well-demarcated, unilocular radiolucent lesion in the right mandibular body, identified during a routine radiographic examination. Based on the clinical hypothesis of a residual cyst, enucleation with curettage was performed, and the specimen was submitted for histopathological analysis. Microscopically, the cystic lesion was predominantly lined by ameloblastomatous epithelium with numerous ghost cells and dentinoid. Additionally, other cystic cavities lined by stratified squamous epithelium with corrugated parakeratin were observed in the fibrous capsule. Based on these features, a final diagnosis of a calcifying odontogenic cyst with odontogenic keratocyst-like areas was established. No recurrence was observed over a 9-year follow-up period. The association of a calcifying odontogenic cyst with odontogenic keratocyst or odontogenic keratocyst-like areas is very rare. To date, this is the second case report in the literature presenting these findings.

Adenoid cystic carcinoma arising in the external auditory canal is rare, and even rarer are cases with sebaceous differentiation mimicking sebaceous carcinoma. This case with clinical, radiologic, gross, and histologic images exemplifies an unusual occurrence of adenoid cystic carcinoma in the external auditory canal with sebaceous differentiation, confirmed by MYB::NFIB fusion.

Primary secretory carcinoma (SC) of the thyroid gland is a rare neoplasm, characterized by the presence of oncogenic ETV6::NTRK3 fusions, which are amenable to tropomyosin receptor kinase (TRK) inhibitor therapy. Despite its morphologic, immunophenotypic, and genetic similarities to SC of the salivary and mammary glands, diagnostic pitfalls may arise in differentiating from papillary thyroid carcinoma due to overlapping features such as papillary growth, nuclear irregularity, and variable expression of PAX8. Tumor misclassification may lead to delayed consideration of molecular testing and targeted therapy. A total of 13 cases of thyroid SC have been documented in the literature, indicating a tendency for advanced clinical presentation followed by a protracted clinical course, with most patients surviving until the end of the study period despite some experiencing recurrences. However, tumor-related mortality occurred in around 30% of cases, with the overall survival ranging from days to years, underscoring the variability in tumor behavior and the need for further research efforts. Among documented cases of thyroid SC, prognostic factors established for salivary SC have shown broad distributions, including a mitotic activity ranging from < 1 to 10 per 10 high-power fields and variable presence of necrosis, awaiting additional case experience to better elucidate their relevance in thyroid SC. We hereby present a 61-year-old female patient with widely metastatic thyroid SC treated with larotrectinib and provide an updated review of the literature on the molecular pathogenesis and clinicopathologic characteristics of this rare entity.

Introduction: Giant cell-rich lesions are a diverse group of lesions that usually occur in bone and contain varying numbers of reactive osteoclastic-type multinucleate giant cells. These lesions present a challenge in pathologic diagnosis, often requiring a combination of clinical, radiographic, and histopathological assessments. The present retrospective observational study aims to provide a concise diagnostic criterion by combining all these parameters, which will aid in effective diagnosis and targeted treatment planning in the future.

Material and method: Previously diagnosed cases of these lesions were taken from the archives and categorized as Central Giant Cell Granuloma (CGCG), CGCG with secondary Aneurysmal Bone Cyst (ABC), primary ABC, and Brown's Tumour. Their demographic characteristics along with clinical, radiological, and histological data were retrieved and compiled into the table. The data was then analyzed and classified into aggressive and non-aggressive CGCG according to the criteria set in the study.

Result: 10 reported cases were of isolated CGCG, 5 were CGCG with secondary ABC, 5 of Brown's tumor and 3 were that of conventional ABC. Out of these, the lesions showing extensive size along with an increased number of giant cells were categorized under aggressive CGCG, whereas those with less aggressive characteristics were categorized under non-aggressive CGCG. The aggressive category comprised 5 cases of isolated CGCG, 2 cases of CGCG with secondary ABC, 3 cases of primary ABC, and 5 of brown tumor, whilst the rest of the cases were categorized under non-aggressive CGCG.

Conclusion: Since all these share overlapping features, thereby this type of concise categorization is the dire need so that the lesions can have a precise diagnosis with treatment and follow-up intervals for aggressive lesions.

Purpose: This scoping review aimed to identify factors associated with the recurrence of ameloblastoma.

Methods: Systematic searches were conducted in PubMed, Scopus, and EMBASE, based on the board research question: "What factors are related to the recurrence of ameloblastoma?". English-language observational studies addressing the risk and preventive factors associated with recurrent ameloblastoma were included and data were extracted.

Results: Eighty-three retrospective observational studies met the inclusion criteria. The identified prognostic factors for recurrence included: (1) Tumor size/diameter/volume, (2) cortical bone perforation/ soft tissue invasion, (3) multilocular radiolucency, (4) impacted tooth-involving lesions, (5) root resorption, (6) WHO classification - conventional (solid/multicystic) ameloblastoma, (7) histological subtype - mural invasion of unicystic ameloblastoma, (8) conservative treatment modalities - simple enucleation, curettage, and marsupialization, and (9) non-extraction/preservation of involved teeth. No strong evidence linked immunohistochemical expression to recurrence. Interestingly, BRAF p.V600E remained controversial in terms of recurrence, despite being a frequent finding in ameloblastoma.

Conclusion: Certain clinical characteristics, radiographic findings, histological subtypes, and treatment choices of ameloblastoma can help identify patients at high risk of recurrence. Further prospective studies to evaluate the prognostic factor model and research on immunohistochemistry are required.

Background: Tyrosine-rich or tyrosine-like crystalloids (TC) were initially described in salivary gland pleomorphic adenoma. The presence of TC in non-neoplastic tissues is rare, and it has been reported exclusively in the larynx. This study aims to characterize the frequency and anatomical localization of TC in total laryngectomy specimens.

Methods: Review of consecutive laryngectomy specimens in which the cassette summary documented parasagittal section sampling of the right and left vocal folds and the anterior commissure. Data collected included patient demographics, underlying diagnoses, history of radiation therapy, presence, and location of TC.

Results: Of 86 laryngectomy specimens, 16 (19%) contained amphophilic to eosinophilic TC. The study cohort included 11 males and 5 females, aged 37 to 85 years (mean 62, median 63). Laryngectomy surgery was performed for advanced untreated squamous cell carcinoma (SCCa) (7/16, 43.75%), recurrent post-treatment SCCa (7/16, 43.75%), previously untreated laryngeal large cell neuroendocrine carcinoma (1/16, 6.25%), and non-functional larynx post-chemoradiation (1/16, 6.25%). According to the macroscopic cassette summary, TC were predominantly found in the anterior commissure Sect. (13/16, 81.25%), with fewer cases in sections containing the left (2/16, 12.5%) or the right (1/16, 6.25%) vocal folds. Microscopically, TC localized to the anterior macula flava and/or adjacent vocal ligament (12/16, 75%) and the anterior commissure tendon (4/16, 25%).

Conclusions: TCs are predominantly reported as admixed with a neoplasm, however this study confirms that TC can also occur in non-neoplastic tissues of the larynx. There was no clear relationship between the presence of TC and prior radiation therapy. TC in the specialized connective tissues of the macula flava and true cord tendinous insertions distinct from tumor may form in response to alterations in mechanical stress, though an age-related change within the spectrum of normal laryngeal microanatomy also remains a possibility.

Palisading adenocarcinoma is a morphologically distinct salivary gland neoplasm that has been recently described with predilection to the sublingual gland. We report our experience with this neoplasm to corroborate and enrich the literature and further clarify its phenotype.

Nodular fasciitis is a rare but benign fibroblastic proliferation that typically presents as a solitary lesion with rapid growth and variable mitotic activity. The lesions usually occur on the extremities and occasionally in the head/neck region. Involvement of the buccal mucosa is extremely rare with only few reports in the literature; in this case report, we describe a 41 year old female who presented with a 6-month history of a stable intraoral lump at the junction of the upper and lower lip. Fine needle aspiration revealed an atypical spindle cell population with plump cells. The surgical excision demonstrated a well circumscribed tan-white firm nodule. Histologic examination revealed a spindle cell proliferation that grew in short, intersecting fascicles with focal storiform architecture. The lesion had a pushing border that was not overtly infiltrative and the stroma contained focal myxoid changes giving a "tissue culture" appearance to the cells. Immunohistochemical testing showed the tumor cells were vimentin (+), SMA (+), weakly Calponin (+), and desmin (-), cytokeratin (-), AE1/AE3 (-), S100 (-), ALK (-), STAT6 (-), and beta-catenin (-). Fluorescence in-situ hybridization (FISH) revealed a USP6 gene rearrangement with an atypical probe pattern. Next generation sequencing identified a novel SPTAN1::USP6 fusion gene confirming the diagnosis of buccal nodular fasciitis. Identification of the characteristic histologic features and USP6 gene rearrangements helped support the diagnosis. A review of the literature identified 25 cases of nodular fasciitis involving the buccal mucosa. The occurrence of this tumor in an unusual location may pose difficulties for diagnosis.