Salivary gland carcinomas (SGCs) are among the most diverse tumors in the head and neck. The WHO Classification of Head and Neck Tumours recognizes 21 subtypes of SGCs, each with its own characteristic morphology, immunophenotype, and molecular alterations. Unlike their counterparts in the major salivary glands, minor salivary gland carcinomas (MSGCs) are less frequently studied. This study aimed to describe the demographic, pathologic, immunohistochemical, and molecular features of all definitively diagnosed MSGCs at our institution. 640 tumors representing 17 subtypes and two emerging entities were identified. Collectively, MSGCs are more common in females. The mean age is 57 years. The most common location is the oral cavity, specifically the palate. The three most common types of MSGC are adenoid cystic carcinoma (AdCC, 26.41
Plasmablastic lymphoma (PBL) is an aggressive neoplasm in which MYC rearrangements are frequent, whereas concurrent BCL2 and/or BCL6 rearrangements are poorly characterized. We investigated MYC, BCL2 and BCL6 rearrangements in a Brazilian series of oral PBL. Thirty cases were confirmed morphologically and immunophenotypically; 23 were evaluable for fluorescence in situ hybridization. MYC rearrangement was detected in 56.5
The diagnosis of digestive neuroendocrine neoplasms (NENs) is increasingly being made on endoscopic biopsies and endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/FNB) or ultrasound biopsies taken from metastases. Although current classification systems provide a robust and elaborate framework for categorizing NENs, their application to limited tissue biopsy samples often remains challenging. A major challenge is the accurate distinction between well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs), which is essential because of their markedly different prognostic and therapeutic implications. Additional challenges include reliable Ki-67 assessment, recognition of intratumoral heterogeneity, and identification of mixed neoplasms, including mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) and amphicrine-like carcinoma (ALC)—a recently introduced and still poorly characterized category—and assignment of the primary site in metastatic disease using organ-associated immunohistochemical markers. Site-specific differences in morphology and immunophenotype further complicate biopsy interpretation and require integration of histological, immunohistochemical, clinical, and radiological findings. Although morphology remains the cornerstone of diagnosis, molecular testing is increasingly used in difficult cases to identify predictive biomarkers and potentially actionable genomic alterations. This review focuses on a practical biopsy-oriented diagnostic approach, discusses major diagnostic pitfalls, controversial and emerging concepts, and highlights the clinicopathological features of NENs across the digestive tract.
Although histopathology is a gold standard for the diagnosis of invasive fungal infections, the morphological analysis does not provide an accurate genus and/or species identification. Because this specific identification is required for antifungal therapy prescription, the implementation of molecular techniques to identify fungi on formalin-fixed, paraffin-embedded (FFPE) tissue in practice is crucial, especially when specimen has not been simultaneously sent to the mycology laboratory. However, such approaches/procedures remain heterogenous. The objective of this systematic review (PROSPERO: CRD420261420594) was to gather data from the literature to support future efforts toward the standardisation of diagnostic practices for fungal identification on FFPE tissue. Among the 1,550 records found on MEDLINE-PubMed and Google Scholar, 57 studies were included. Thirty-two, 27, and 10 studies investigated the use on FFPE tissue of taxon-specific fungal PCR (n = 1421 FFPE samples tested), panfungal PCR followed by Sanger sequencing (n = 1647 FFPE samples tested), and targeted next-generation sequencing/massive parallel sequencing (NGS/MPS) or untargeted metagenomics (n = 408 FFPE samples tested; some studies reported several techniques), respectively. The sensitivity and specificity of the techniques, according to pre-analytical, histopathological, and molecular criteria were reported and discussed. Advantages and limitations of each technique are presented. While taxon-specific fungal PCR are widely available and highly sensitive, sequencing-based techniques have a broader spectrum for identification purpose. Finally, because of the contamination of tissue sections and the presence of fungi belonging to microbiota on samples, the molecular identification should always be correlated to the pathogenic fungi’s morphology, to ensure an accurate and reliable integrated histomolecular diagnosis.
