Solid Variant of Adenoid Cystic Carcinoma: Difficulties in Diagnostic Recognition

Unraveling the Role of Epithelial-Mesenchymal Transition in Adenoid Cystic Carcinoma of the Salivary Glands: A Comprehensive Review

Salivary adenoid cystic carcinoma (SACC) is considered a challenging malignancy; it is characterized by a slow-growing nature, yet a high risk of recurrence and distant metastasis, presenting significant hurdles in its treatment and management. At present, there are no approved targeted agents available for the management of SACC and systemic chemotherapy protocols that have demonstrated efficacy remain to be elucidated. Epithelial-mesenchymal transition (EMT) is a complex process that is closely associated with tumor progression and metastasis, enabling epithelial cells to acquire mesenchymal properties, including increased mobility and invasiveness. Several molecular signaling pathways have been implicated in the regulation of EMT in SACC, and understanding these mechanisms is crucial to identifying new therapeutic targets and developing more effective treatment approaches. This manuscript aims to provide a comprehensive overview of the latest research on the role of EMT in SACC, including the molecular pathways and biomarkers involved in EMT regulation. By highlighting the most recent findings, this review offers insights into potential new therapeutic strategies that could improve the management of SACC patients, especially those with recurrent or metastatic disease.

DNA methylation-based classification of sinonasal tumors

The diagnosis of sinonasal tumors is challenging due to a heterogeneous spectrum of various differential diagnoses as well as poorly defined, disputed entities such as sinonasal undifferentiated carcinomas (SNUCs). In this study, we apply a machine learning algorithm based on DNA methylation patterns to classify sinonasal tumors with clinical-grade reliability. We further show that sinonasal tumors with SNUC morphology are not as undifferentiated as their current terminology suggests but rather reassigned to four distinct molecular classes defined by epigenetic, mutational and proteomic profiles. This includes two classes with neuroendocrine differentiation, characterized by IDH2 or SMARCA4/ARID1A mutations with an overall favorable clinical course, one class composed of highly aggressive SMARCB1-deficient carcinomas and another class with tumors that represent potentially previously misclassified adenoid cystic carcinomas. Our findings can aid in improving the diagnostic classification of sinonasal tumors and could help to change the current perception of SNUCs.

Low-risk triple-negative breast cancers: Clinico-pathological and molecular features

Triple-negative breast cancers (TNBC) comprise biologically and clinically heterogeneous diseases characterized by the lack of hormone receptors (HR) and HER2 expression. This subset of tumors accounts for 15-20% of all breast cancers and pursues an ominous clinical course. However, there is a spectrum of low-risk TNBCs with no/minimal metastatic potential, including the salivary gland-type tumors, those with extensive apocrine differentiation and/or high tumor-infiltrating lymphocytes, and small-sized, early-stage (pT1a/bN0M0) TNBCs. De-escalating the treatment in low-risk TNBC, however, is not trivial because of the substantial lack of dedicated randomized clinical trials and cancer registries. The development of new diagnostic and/or prognostic biomarkers based on clinical and molecular aspects of low-risk TNBCs would lead to improved clinical treatment. Here, we sought to provide a portrait of the clinicopathological and molecular features of low-risk TNBC, with a focus on the diagnostic challenges along with the most important biological characteristics underpinning their favorable clinical course.

Treatment response to eribulin and anlotinib in lung metastases from rare perianal adenoid cystic carcinoma: a case report

Adenoid cystic carcinoma (ACC) is a rare salivary glands tumor and often displays aggressive behavior with frequent relapse and metastasis. The terminal ACC lacks standard treatment guidelines and is always accompanied by poor prognosis. Here, we report a case of rare perianal ACC who received resection and palliative adjuvant radiation. Five years later, PET-computed tomography (CT) showed perianal recurrence and multiple pulmonary metastases. Combined chemotherapy with doxorubicin, carboplatin and cyclophosphamide was applied for two cycles but ineffective. Further next-generation sequencing analysis of perianal tissue demonstrated the v-myb avian myelobastosis viral oncogene homolog and nuclear factor I/B fusion gene and two novel BCL-6 corepressor (BCOR) mutations (p.F1106Tfs*5 and p.L1524Hfs*8). The therapy was switched to eribulin and anlotinib and has been performed for eight cycles. At recent follow-ups, MRI and CT examinations revealed the diminishing perianal and pulmonary lesions. This study presented the first case of perianal ACC with multiple pulmonary metastases and particular BCOR mutations, who presented a durable response to eribulin and anlotinib, providing a potential therapeutic option for advanced refractory ACC.

Immunophenotypical alterations with impact on the epithelial-mesenchymal transition (EMT) process in salivary gland adenoid cystic carcinomas

Adenoid cystic carcinoma (ACC) is one of the most common malignant salivary glands neoplasms with an indolent clinical course, slow-growing but locally aggressive and quite often with delayed recurrence and distant metastasis. In order to elucidate this tumoral behavior, we conducted an immunohistochemical study investigating the alterations of epithelial phenotype with anti-cytokeratin (CK) AE1/AE3 and anti-E-cadherin antibodies, and the acquisition of mesenchymal phenotype with vimentin, fibronectin, N-cadherin and P-cadherin in salivary ACCs. Thus, we recorded a reduction of CK AE1/AE3, E-cadherin, P-cadherin and fibronectin reactivity in the solid variant and especially in the cells from the periphery of invasive neoplastic proliferations, regardless histological type. These phenotypical alterations suggest the involvement of the epithelial–mesenchymal transition (EMT) process in the progression of salivary ACCs.

A Case of Solid Variant of Adenoid Cystic Carcinoma from Trachea: A Case Report and Review of Literature

Introduction

Primary tracheal adenoid cystic carcinoma (ACC) is a rare and heterogeneous group of neoplasms arising from the respiratory tract. The solid variant of ACC is a histologically distinct subtype with an unfavorable clinical course. We report on a case of tracheal ACC with immunohistochemical and molecular analysis together with a review of the literature.

Case Report

We observed a case in which a 31-year-old male presented with a neoplasm bulging into the lumen and caused symptoms of tracheal obstruction and even hemoptysis. Cytological smears of an endobronchial fine needle aspiration revealed aggregates of basaloid cells with small to medium size, scant cytoplasm, and evenly hyperchromatic nuclei. Histologically, the tumor is characterized by a predominant compact sheet-like and nested pattern of rounded basaloid cells. Immunohistochemically, the tumor was diffusely positive for CK and CD117. CK7 and CK5/6 were focally positive in the genuine glandular structures. P63 was completely negative in the majority of neoplastic cells. Fluorescence in situ hybridization analysis revealed MYB gene rearrangement.

Conclusion

The solid variant of ACC from trachea is rare and hence poses diagnostic difficulty. Computed tomography (CT) scan and bronchoscopy help assess the extent of the disease. Histological features combined with immunophenotypic and molecular analysis aid in distinguishing this uncommon type from other round cell neoplasms. The accurate diagnosis can help expedite treatment of this highly aggressive tumor.

Metastatic Basal Cell Carcinoma of the Skin: A Comprehensive Literature Review, Including Advances in Molecular Therapeutics

Basal cell carcinoma (BCC) of the skin is the most common type of malignant human tumor. In Europe, the incidence of BCC ranges from 44.6 to 128 cases per 100,000 inhabitants annually, whereas in the United States, the yearly incidence rate ranges between 500 and 1500. The global incidence has been calculated to be as high as 10 million cases of BCC per year. There are 2 main clinical patterns of BCC-the familial BCC in basal cell nevus syndrome and sporadic BCC. The etiology of cutaneous BCC is usually the result of the interaction between solar ultraviolet radiation and genetic factors. Somatic or germline mutations in the effector components of the hedgehog signaling pathway (ie, PTCH1, PTCH2, SMO or SUFU genes) are responsible for ∼90% of the cases of both sporadic and familial BCC, all causing a constitutive activation of the hedgehog pathway. Cutaneous BCC very rarely metastasizes, and diagnosis in metastatic sites can be very difficult. Metastatic BCC has weakly effective therapeutic options with a poor prognosis until few years ago. In 2012, small-molecule therapies, involving inactivation of the hedgehog signaling pathway, and capable of reducing tumor growth and progression have been introduced into clinical practice for advanced (locally advanced or metastatic) BCC. We performed a comprehensive literature review on metastatic BCC and found at least 915 cases reported to date. In addition, we extensively discussed the differential diagnosis of metastatic BCC, and outlined the advances in clinical therapeutics involving these small molecules.

Prognostic importance of RUNX1 expression for head and neck adenoid cystic carcinoma

OBJECTIVE

In the present study, we aimed to investigate the prognostic value of RUNX1 expression in 76 patients with adenoid cystic carcinoma (ACC).

MATERIALS AND METHODS

All cases were arranged in tissue microarray blocks and submitted to immunohistochemistry against RUNX1. These results were statistically correlated with clinicopathologic features, including age, gender, tumour site, tumour size, lymph node status, AJCC clinical stage, distant metastasis, treatment, recurrences, follow-up, histologic pattern, vascular and neural invasion, all of which obtained from patient's medical records.

RESULTS

RUNX1 was expressed in the nuclei of tumour cells, with a mean of 18.1% of positivity. Nuclear RUNX1 expression was significantly associated with AJCC clinical stage (p < .0001), solid histologic pattern (p < .0001), vascular invasion (p < .0001) and presence of local recurrence (p < .0001). Using univariate and multivariate analyses, RUNX1 nuclear expression was significantly associated with a lower disease-free survival (p < .0001 and p = .028, respectively) and disease-specific survival (p < .0001 and p = .018, respectively) rates.

CONCLUSION

In summary, RUNX1 nuclear expression may represent an indicator of unfavourable outcome for patients affected by head and neck ACC.

Histopathological Findings of Intraoral Pleomorphic Adenomas: A Retrospective Study of a Case Series

The aim of this study was to describe the clinicopathological features of 21 cases of intraoral pleomorphic adenoma (PA), with emphasis on histopathological findings. Between 2000 and 2016, all patients diagnosed as intraoral PA were retrieved and histopathological slides stained with hematoxylin and eosin reviewed to confirm the diagnosis. All tumors were classified histologically according to Seifert et al (1980). The clinical and histopathological variables were analyzed using the Fisher's exact test, considering a significance level of 5% (P < .05). Plasmacytoid (85.7%), spindle (38.1%), and epithelioid (9.5%) myoepithelial cells were observed. Oncocytic (47.6%) and mucous (19%) cells were also found. The stroma was predominantly fibrous (95.2%), followed by myxoid (66.7%), hyaline (61.9%), and chondromyxoid (33.3%). Squamous (57.1%), adipose (47.6%), sebaceous (14.3%), and bone (14.3%) differentiations were found. Additionally, a group of tumors presented pleomorphism (23.8%), mitoses (14.3%), capsule infiltration (9.5%), and necrosis. The presence of cystic structures occurred significantly in patients older than 30 years (P = .04) and mitoses were more observed in PA from buccal mucosa (P = .026). All cases that presented plasmacytoid cells were smaller than 1.5 cm (P = .015). All tumors with up to 50% stroma area presented with size smaller than 2.0 cm (P = .013). Intraoral PA presents a large morphological spectrum and several microscopic features are associated with clinical findings.