Pleomorphic adenoma histology, parotid salivary gland, examined by bright-field microscopy on Hematoxylin and Eosin stained sections. Imaging modality: Light microscopy; technique: Hematoxylin and Eosin staining. The sample reveals a classic biphasic neoplasm comprising epithelial ductal structures and myoepithelial cells embedded in an abundant stromal backdrop. Epithelial components form cords, ducts, and small island formations lined by cuboidal to columnar cells with eosinophilic cytoplasm and hyperchromatic nuclei. Intermixed myoepithelial cells display plasmacytoid or spindle morphologies, often surrounding epithelial elements. The stroma is a prominent feature, ranging from basophilic, myxoid to more eosinophilic, hyalinized areas. The myxoid matrix is rich in glycosaminoglycans and imparts a loose, gelatinous appearance, while hyalinized zones contribute dense eosinophilic bands. Overall architecture is often well circumscribed with minimal pleomorphism and low mitotic activity, consistent with benign behavior. Clinical significance includes differentiation from malignant salivary tumors; prognosis is favorable with complete surgical excision. Differential considerations include mucoepidermoid carcinoma, adenoid cystic carcinoma, basal cell adenoma, and Warthin tumor. This image is useful for educational purposes in pathology, otolaryngology, and head-and-neck surgery, illustrating quintessential pleomorphic adenoma features: epithelial and myoepithelial proliferation in a chondromyxoid stroma, with duct-like structures and a variable stromal composition. This histologic pattern aids diagnosis and education.

Pleomorphic adenoma of a major salivary gland (parotid) is depicted on hematoxylin and eosin stained histology. The lesion is a well circumscribed, encapsulated neoplasm: a thick fibrous capsule delineates tumor from adjacent normal parotid tissue seen in the upper right, with the mass projecting toward the lower left. The tumor shows biphasic histology with epithelial elements forming duct-like structures and nests, embedded in a variably myxoid to chondromyxoid stroma. Epithelial cells range from cuboidal to columnar, often arranged in sheets and tubules, while myoepithelial cells display plasmacytoid to spindle morphologies, contributing to a heterogeneous, hyalinized background. The stroma may contain cartilaginous or osseous-like foci in places; overall architecture remains orderly rather than infiltrative. Capsule integrity is a key diagnostic cue; the capsule here is thick and typically prevents invasion, although small capsular breaches may explain rare recurrences if not completely excised. No significant necrosis or high mitotic activity is observed. Clinically, this benign mixed tumor presents as a slow-growing, painless parotid mass with preserved facial nerve function. Differential diagnoses include basal cell adenoma and Warthin tumor; mucoepidermoid carcinoma must be considered when ductal differentiation or invasion is suspected. The image highlights the classic pleomorphic adenoma biology: myxoid/chondroid stroma with epithelial/myoepithelial components within a robust capsule.

Histology of a pleomorphic adenoma involving the parotid gland. This light-microscopy image derives from a hematoxylin and eosin–stained paraffin section. It demonstrates a biphasic neoplasm with epithelial ductal–acinar elements embedded in a myxoid to chondromyxoid stroma. Epithelial components arrange as trabeculae, tubules, and duct-like acini, often lined by a two-layered cast: inner cuboidal to columnar luminal cells and outer basal/myoepithelial cells with plasmacytoid or spindle morphology. The surrounding stroma is variably myxoid, sometimes chondroid, producing a lobulated architecture with intimately interwoven cellular and stromal zones. Clefts and interspersed myxoid pools may be evident; ossification or calcifications are occasional. The lesion is typically well circumscribed within the parotid, showing no frank invasion of adjacent parenchyma on histology. Mitotic activity is rare. The overall appearance—myxoid/chondromyxoid matrix with epithelial tubules and ducts—supports pleomorphic adenoma; however, histologic overlap with other salivary gland neoplasms necessitates clinical correlation and, when indicated, ancillary immunohistochemistry (e.g., cytokeratin, S-100, GFAP) or molecular testing. Clinically, pleomorphic adenoma presents as a slow-growing, painless parotid mass in adults, with a favorable prognosis after complete surgical excision, though recurrence and potential for malignant transformation exist if spillage or capsular rupture occurs.

Low-power brightfield histology of a salivary gland tumor stained with hematoxylin and eosin reveals the classical pleomorphic adenoma pattern. The lesion is encapsulated within the parotid region, presenting as a benign, slow-growing mass. The epithelial component forms duct-like and acinar structures lined by a single layer of cuboidal to columnar cells, while an outer layer of neoplastic myoepithelial cells displays plasmacytoid, spindled, or stellate morphologies. The stroma is variably myxoid to chondroid, producing a heterogeneous, often cartilaginous appearance and imparting the 'pleomorphic' descriptor. Cellular atypia and mitotic activity are absent or minimal, consistent with benign behavior. The lesion demonstrates biphasic architecture with a mosaic of epithelial nests, cords, and tubules embedded in an abundant extracellular matrix rich in mucopolysaccharides and chondroid material; occasional hyalinization may be seen. Clinically, this histology corresponds to a pleomorphic adenoma, the most common benign salivary gland neoplasm, characteristically presenting in adults with a painless, mobile mass. Differential diagnoses include mucoepidermoid carcinoma, adenoid cystic carcinoma, and basal cell adenoma; however, the combination of ductal epithelial cells with myoepithelial myxochondroid stroma supports benign pleomorphic adenoma. The diagnostic significance lies in confirming a benign, surgically curable process requiring complete excision to minimize recurrence. Correlation with clinical exam advised today.

A clinical intraoperative photograph showing the anatomical arrangement of the facial nerve branches in a surgical dissection, following parotidectomy. The image provides a lateral view of the cervicofacial region where the parotid gland has been removed to expose the extratemporal facial nerve plexus. Labeled branches include the temporal branch extending superiorly, the zygomatic and buccal branches traveling toward the mid-face, and the marginal mandibular and cervical branches descending inferiorly. The cervical branch is depicted in close proximity to the jugular vein, which is visible in the lower surgical field. Surgical instruments (retractors) are positioned to maintain exposure of the deep tissues. A 5mm grid scale is included for anatomical measurement. This visual serves as an educational guide for surgical anatomy, identifying key landmarks for nerve preservation during parotid gland surgery or facial nerve decompression.

This clinical photograph displays a high-magnification surgical dissection of the facial nerve (Cranial Nerve VII) and its extratemporal branches. The image highlights the anatomical arrangement after the parotid gland has been removed. Blue surgical background material is placed beneath the nerves to enhance visual contrast. Visible and labeled branches radiating from the main trunk include the temporal, zygomatic, buccal, marginal mandibular, and cervical branches. Additionally, the posterior auricular branch is visible posteriorly, while the posterior digastric and stylohyoid branches are shown inferiorly. The branches appear as glistening, whitish-cord structures overlying surrounding muscle and connective tissue. This educational visual demonstrates the typical branching patterns and spatial relationships essential for parotidectomy procedures, maxillofacial surgery, and head and neck anatomy education. The labels indicate the specific distribution of motor innervation to the muscles of facial expression.

This clinical intra-operative photograph displays a large-scale dissection of the parotid and facial region during a total parotidectomy. The surgical field reveals an anatomical display of the facial nerve (Cranial Nerve VII) and its distal branching network preserved and traversing the surgical void created by the resection of the parotid gland. Key structures visible include the masseter muscle superiorly, the sternocleidomastoid muscle at the inferior margin, and the external ear at the lower right, where a surgical retractor is positioned for tissue displacement. Multiple fine nerve branches are seen branching across the exposed muscle bed and subcutaneous fat. The image demonstrates a 'Type 0 defect,' characterized by an intact facial nerve following tumor resection. This visual serves to educate on the intricate neurovascular anatomy of the head and neck, specifically highlighting surgical landmarks necessary for nerve preservation during oncological resections in otorhinolaryngology and maxillofacial surgery.

This intraoperative clinical photograph displays an anatomical dissection of the facial nerve (Cranial Nerve VII) within the parotid region. The image illustrates a 'Type II' branching pattern characterized by a single facial nerve trunk (FNT) that divides directly into multiple terminal branches. Notably, this variant lacks the typical primary bifurcation into temporofacial and cervicofacial divisions. The nerve branches appear as thin, pale, string-like structures radiating through the reddish, fleshy tissue of the surgical field. The surrounding area shows exposed glandular and soft tissue relevant to a parotidectomy procedure. This visual serves as an educational reference for surgical anatomy, highlighting normal anatomical variations of the extracranial facial nerve that are critical for surgeons to identify during parotid gland surgery to avoid nerve injury and post-operative facial paralysis.