Histiocytic sarcoma affecting the oral cavity (CD163/Lysozyme)! Discover more in our @SpringerNature book Lymphoproliferative and granulomatous disorders of the oral cavity link.springer.com/book/97830… #Pathology #OralPathology #OralMedicine #lymphoma #PathTwitter #hemepath

Oropharynx exophytic lesion: SCC? Tonsillar crypts are lined by a unique reticulated epithelium. The basement membrane is disrupted and non-contiguous, allowing the epithelium easy access to lymphatics. - There is no crypt dysplasia or in situ carcinoma in oropharyngeal HPV SCC. - All HPV-related neoplasia of the tonsils should be regarded as malignant even in the absence of "classic" histologic features of invasion. Dr. Cipriani #USCAP2026 #pathology #PathX #PathTwitter

Photos from Biopticka multihead seminars of ectomesenchymal chondromyxoid tumor of the tongue Benign tumor with predilection for the anterior dorsal tongue Well demarcated , Stroma may be hyalinized , myxoid or chondromyxoid sheets of oval, round, bland cells

Just out in AJSP – a paper from our group describing a MAJOR new oddity. Tumors that normally arise in the jaw from tooth🦷precursors (ameloblastoma) – but as lung primaries 🫁! This was a neat collaboration b/w MSKCC, Mayo and UTSW where these cases were encountered independently, and we put our heads together with the help of original contributors and fellows to tackle this puzzle. Time will tell if these are truly exceptional or have been underrecognized. journals.lww.com/ajsp/fullte… @JLHornick @ENTpathology @MSKPathology @PulmPathSoc @yro854 @thoracicpath @Path_Matt @SansanoValero @AndreMo77438628

The structures you’re seeing are aberrant products of odontogenesis, I see it often in the wall of many developmental odontogenic cysts or dental follicles, there are not specific. Also, the respiratory lining can be seen in many odontogenic cysts especially if they are in close proximity to the maxillary sinus. My guess is Dentigerous cyst, but I have to correlate radiographically

🦷 Granular Cell Ameloblastoma (GCA) 📖 Definition Granular Cell Ameloblastoma (GCA) is a rare histological variant of conventional ameloblastoma, a benign but locally aggressive odontogenic epithelial tumor, characterized by peripheral ameloblast-like cells and a central stellate-reticulum–like component. In the granular variant, the central cells acquire abundant eosinophilic granular cytoplasm, due to the accumulation of lysosomes【WHO 2022】. 📊 Epidemiology Ameloblastoma accounts for about 1% of all head and neck neoplasms. The granular cell subtype represents approximately 3–5% of cases【PathologyOutlines】. Most common in the mandible (87%), especially the posterior region. Age range: adults in the 3rd to 5th decade, though it may occur across a broad age spectrum. No significant sex predilection. 🧬 Etiology / Pathophysiology Exact etiology remains unknown. Molecular pathogenesis: Alterations in the MAPK/ERK pathway are the most common. BRAF p.V600E mutation is the most frequent, especially in mandibular tumors. Less common mutations: RAS and FGFR2. In the granular subtype, cytoplasmic granularity results from lysosomal accumulation in central cells, interpreted as a degenerative/metabolic process rather than an independent prognostic marker. 🤒 Clinical Manifestations Slow-growing, painless swelling in the mandible or maxilla. May cause: Cortical bone expansion and perforation. Tooth mobility or loss. Local paresthesia in larger tumors. If untreated, it may become large, leading to facial deformity and involvement of adjacent structures. 🧪 Laboratory Diagnosis No specific serum biomarkers. Histopathological evaluation is mandatory for diagnosis. Molecular testing (e.g., BRAF status) may aid in prognostic stratification and targeted therapy selection. 🖼️ Imaging and Pathology Findings Radiology Multilocular radiolucency with “soap bubble” or “honeycomb” appearance, well-corticated margins. CT (preferably contrast-enhanced): better defines size, content, cortical expansion, and perforation. Associated with impacted teeth in up to 18% of cases. Histopathology Epithelial islands in fibrous stroma. Peripheral cells: columnar/cuboidal, hyperchromatic nuclei, reverse polarity, subnuclear vacuolization. Central cells: stellate-reticulum–like, but with abundant eosinophilic granular cytoplasm filled with lysosomes. No significant atypia or mitotic activity. May coexist with other histological patterns (follicular, plexiform, etc.). 🔍 Differential Diagnosis Granular cell tumor (Abrikossoff’s tumor): soft tissue lesion, S100 , lacks ameloblastomatous architecture. Oncocytic odontogenic tumor: granular cytoplasm, different growth pattern. Other ameloblastoma subtypes (acanthomatous, follicular, plexiform, etc.). Odontogenic carcinoma (rare, in atypical or aggressive cases). 📉 Prognosis / Complications Locally aggressive behavior, similar to conventional ameloblastoma. Recurrence risk is high with conservative treatment (simple curettage → up to 60–80%). No evidence that the granular morphology alone alters prognosis compared with other variants. Potential for significant local destruction and functional impairment. Malignant transformation (malignant ameloblastoma / ameloblastic carcinoma) is exceedingly rare. 💊 Treatment Radical surgical resection with negative margins (>1 cm beyond radiographic limits). Options: segmental mandibulectomy or maxillectomy, depending on size and location. Conservative approaches carry high recurrence rates. Long-term follow-up (10–20 years) is essential due to late recurrences. Emerging therapies: BRAF inhibitors (± MEK inhibitors) in unresectable or metastatic cases, with early promising results. 📝 Summary Granular Cell Ameloblastoma (GCA) is a rare variant of ameloblastoma, histologically defined by eosinophilic granular cytoplasm in central tumor cells. Despite its peculiar morphology, its biological behavior is comparable to conventional ameloblastoma: benign but infiltrative, slow-growing, locally destructive, and prone to recurrence after conservative surgery. Management requires radical resection with long-term surveillance. #️⃣ #MedicalEducation #NotasDePatologia ⚠️ Disclaimer: This text is intended for educational purposes only and does not replace individualized medical or pathological evaluation. 📚 References: WHO Classification of Tumours Editorial Board. Head and Neck Tumours. 5th ed. Lyon: IARC; 2022. PathologyOutlines.com. Ameloblastoma. Available at: pathologyoutlines.com 🖋️ Case and slide coloration courtesy of Dr. Alexandre Carneiro (@AmcarneiroMD), as part of an academic partnership project.

🦷 Clear Cell Odontogenic Carcinoma 📌 Definition Clear cell odontogenic carcinoma (CCOdC) is a rare malignant odontogenic tumor characterized by sheets, nests, or cords of clear cells within a fibrocellular or hyalinized stroma. It is considered a locally aggressive carcinoma with potential for recurrence and metastasis. 🌍 Epidemiology Fewer than 150 cases reported. Mean age: ~53 years. Female predominance (~63%). Mandible is the most frequent site (≈75%), especially posterior body and ascending ramus. 🧬 Etiology & Pathogenesis Etiology remains unknown. Molecular hallmark: EWSR1 rearrangements (>80% of cases). Most common partner: ATF1. Less frequent partners: CREB1 and CREM. Morphological and immunophenotypic overlap with salivary gland hyalinizing clear cell carcinoma, suggesting a shared pathogenetic mechanism. 🧑‍⚕️ Clinical Features Slowly progressive jaw swelling. May present with: Pain or tenderness. Tooth mobility. Paraesthesia. Mucosal ulceration (advanced cases). Less frequent: lymphadenopathy and distant metastases. 🩻 Imaging Findings Expansile, poorly defined radiolucencies. Frequent tooth root resorption. 🔬 Pathology Macroscopic Intraosseous, tan-white mass. Ill-defined borders. May extend into adjacent soft tissues. Histopathology Lobular sheets, nests, or trabeculae of polygonal cells with clear to eosinophilic cytoplasm. Hyalinized or fibrocellular stroma. Peripheral palisading may be seen. Clear cells: PAS-positive, diastase-sensitive (glycogen-rich). Low mitotic index, but perineural invasion can occur. Necrosis and angiolymphatic invasion uncommon. Immunohistochemistry Positive: AE1/AE3, CK5/6, CK19, p63, EMA. Negative: SMA, calponin, S100. 🧾 Differential Diagnosis Odontogenic tumors: Clear cell calcifying epithelial odontogenic tumor. Odontogenic fibroma (amyloid subtype). Salivary tumors (intraosseous or metastatic): Mucoepidermoid carcinoma. Epithelial-myoepithelial carcinoma. Metastatic neoplasms: Renal cell carcinoma. Melanoma. Other odontogenic carcinomas: Odontogenic carcinoma with dentinoid (may show clear cells, but produces dentinoid). 🧪 Diagnostic Molecular Pathology Detection of EWSR1 rearrangement supports diagnosis. Interpretation may be challenging in decalcified samples. 📊 Staging No specific AJCC/UICC TNM system. ICCR (International Collaboration on Cancer Reporting) datasets recommended for structured reporting. 📉 Prognosis & Complications High recurrence risk (~40%). Metastases: cervical lymph nodes most common; lungs and bones less frequent. Mortality: ~11%. Late recurrences/metastases may occur, underscoring need for long-term follow-up. 💊 Treatment First-line therapy: complete surgical resection with wide margins. Role of adjuvant radiotherapy/chemotherapy: not well defined, may be considered in recurrent/metastatic cases. 📝 Summary Clear cell odontogenic carcinoma is a rare and aggressive odontogenic malignancy. It primarily affects the mandible, often presents with swelling and pain, and shows distinctive clear cell morphology with EWSR1 rearrangements. Despite its rarity, it requires aggressive surgical management due to high recurrence rates and potential for metastasis. 📚 Reference WHO Classification of Head and Neck Tumours, 5th Edition, 2022. ⚠️ Disclaimer: Educational content only. Not a substitute for clinical diagnosis or patient management. 🖋️ Case and slide coloration courtesy of Dr. Alexandre Carneiro (@AmcarneiroMD), as part of an academic partnership project. #MedicalEducation #NotasDePatologia