Head & Neck Pathology最新文献

Purpose: The current study aimed to investigate the use of surrogate immunohistochemical (IHC) markers of proliferation and stem cells to distinguish ameloblastoma (AB) from ameloblastic carcinoma (AC).

Methods: The study assessed a total of 29 ACs, 6 ABs that transformed into ACs, and a control cohort of 20 ABs. The demographics and clinicopathologic details of the included cases of AC were recorded. The Ki-67 proliferation index was scored through automated methods with the QuPath open-source software platform. For SOX2, OCT4 and Glypican-3 IHC, each case was scored using a proportion of positivity score combined with an intensity score to produce a total score.

Results: All cases of AC showed a relatively high median proliferation index of 41.7%, with statistically significant higher scores compared to ABs. ABs that transformed into ACs had similar median proliferation scores to the control cohort of ABs. Most cases of AC showed some degree of SOX2 expression, with 58.6% showing high expression. OCT4 expression was not seen in any case of AC. GPC-3 expression in ACs was limited, with high expression in 17.2% of ACs. Primary ACs showed higher median proliferation scores and degrees of SOX2 and GPC-3 expression than secondary cases. Regarding SOX2, OCT4 and GPC-3 IHC expression, no statistically significant differences existed between the cohort of ABs and ACs.

Conclusion: Ki-67 IHC as a proliferation marker, particularly when assessed via automated methods, was helpful in distinguishing AC from AB cases. In contrast to other studies, surrogate IHC markers of embryonic stem cells, SOX2, OCT4 and GPC-3, were unreliable in distinguishing the two entities.

Introduction: Striated duct adenoma (SDA) is a rare benign salivary gland tumor with a recently described genetic signature. Recurrent oncogenic mutations affecting the IDH2 gene differentiate SDA from its primary differential diagnosis of canalicular adenoma. Here, we report a case of SDA affecting the parotid gland with IDH1/2 mutation-specific immunohistochemical positivity. Additionally, we provide a scoping review developed according to the Cochrane Methodology and reported following the Joana Briggs Institute (JBI) checklist to synthesize all previously published cases of SDA. The review protocol was registered on the Open Science Framework (OSF) platform ( https://osf.io/7mztg ). The searches were performed using Medline, Embase, Web of Science, and LILACS, with no date or language limit. Studies were evaluated for eligibility, extracted, and compiled in a narrative form. Seven studies with 20 patients with SDA, including ours, were analyzed. The tumors mainly affected the parotid gland (13/20) in patients with a mean age of 62 years and did not display sex predilection. Swelling was the leading clinical symptom. The mean follow-up duration was 26 months with no recurrence or metastasis after resection.

Conclusion: Awareness of the clinicopathological features and the use of IDH1/2 mutation-specific immunohistochemistry are pivotal for the consistent identification of SDA, and assessment for true biological potential will require increased follow-up and scrutiny.

Background: Metastatic intestinal adenocarcinoma involving the mandible is rare, posing diagnostic challenges because of its unusual presentation.

Case presentation: A 55-year-old male presented with a rapidly growing mass in the right mandible, accompanied by facial asymmetry and vestibular obliteration. Histopathological examinations revealed features consistent with adenocarcinoma. Immunohistochemical analysis supported the diagnosis of intestinal adenocarcinoma, with subsequent metastasis confirmed by PET scan findings.

Diagnosis: The lesion was conclusively diagnosed as intestinal adenocarcinoma metastasizing to the mandible.

Management: The patient pursued treatment at a government facility, leading to a loss of follow-up.

Purpose: The field cancerization concept indicates the presence of pre-cancerous changes in clinically normal tissue surrounding the tumor. In squamous cell carcinoma of the oral tongue (SCCOT) which is infrequently linked to human papillomavirus infection, we have previously reported that clinically normal tongue contralateral to tumor (NTCT) is molecularly abnormal. Here, combining our transcriptomic and genomic data, we aimed to investigate the contribution of molecular changes in NTCT to cancer development.

Methods: Microarray gene expression data of 14 healthy controls, 23 NTCT and 29 SCCOT samples were investigated to characterize transcriptional profiles in NTCT. Whole exome sequencing and RNA-sequencing data of paired NTCT and tumor samples from 15 SCCOT patients were used to study correlation between copy number variation and differential gene expression.

Results: Using supervised multivariate partial least squares discriminant analysis, a total of 61 mRNAs that distinguish NTCT from healthy tongue were selected. Functional enrichment analysis of the 22 upregulated genes showed increased "positive regulation of nitrogen compound metabolic process" in NTCT. All 12 genes involved in this process have roles in apoptosis (anti- and/or pro-apoptotic). Compared to healthy controls, Zinc Finger Protein 395 (ZNF395), a pro-apoptotic tumor suppressor located on chromosome 8p, was the only gene showing increased mRNA level in NTCT whereas decreased in SCCOT. Given the frequent loss of chromosome 8p in SCCOT, the impact of ZNF395 copy number variation on gene expression was further examined, revealing a positive correlation between copy number and mRNA level (correlation coefficient = 0.572, p < 0.001).

Conclusion: NTCT is susceptible to malignant transformation, where tissue homeostasis is maintained at least partly through regulation of apoptosis. Loss of the pro-apoptotic gene ZNF395 could thus initiate cancer development.

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.