Pleomorphic adenoma with extensive squamous metaplasia and keratin cyst formations in minor salivary gland: a case report

Pleomorphic adenoma (PA), the most common salivary gland tumor, accounts for 54 to 65% of all salivary gland neoplasias and 80% of the benign salivary gland tumors. It most frequently affects the parotid gland, followed by the submandibular and the minor salivary glands. Microscopically, mucous, sebaceous, oncocytic and squamous metaplasia, sometimes with the formation of keratin pearls, may be present, but the latter rarely results in the formation of extensive keratin-flled cysts lined by squamous epithelium. Extensive squamous metaplasia can be mistaken for malignancy, including mucoepidermoid carcinoma and squamous cell carcinoma. Here, we present an unusual case of PA with extensive squamous metaplasia and keratin cyst formations in a minor salivary gland, and discuss its microscopic features, including the immunohistochemical characteristics, and differential diagnosis of this uncommon presentation

Neohygrocybe Herink

Key to all species of <i>Neohygrocybe</i> worldwide <p> <b> including ones named in <i>Hygrocybe</i></b> </p> <p>1. Lamellae changing colour when bruised (pink, red, brown or black)................................................................................................2</p> <p>1’. Lamellae not changing colour with bruising......................................................................................................................................7</p> <p>2. Lamellae at least initially bruising pink, red or reddish brown..........................................................................................................3</p> <p>2’. No pink or red bruising reactions, but may bruise directly to brown or black...................................................................................6</p> <p>3. Pileus and stipe dark greyish brown; odour not distinctive................................................................................................................4</p> <p>3’. Pileus and stipe usually paler, pale drab grey or pale reddish brown; odour often distinct...............................................................5</p> <p> 4. Basidiomes large, 30–35 mm; basidiospores 7–9 µm long, subtropical China............................................................ <i>N. griseonigra</i></p> <p> 4’. Basidiomes smaller, 20–25 mm; basidiospores 6–7.5 µm long; in Australia............................................................... <i>N. lawsonensis</i></p> <p> 5. Odor fruity or fragrant; basidiospores subglobose, 5–7 × 5–6 µm, E. North America and Puerto Rico, Caribbean........ <i>N. subovina</i></p> <p> 5’. Odour alkaline; basidiospores larger and ellipsoid, 7–8.5 × 4.5–5 µm, New Zealand......................................................... <i>N. innata</i></p> <p> 6. Pileus large, 20–90 mm, margin dark; basidospores 7–9.5 µm long; pseudocystidia absent; odour unpleasant or nitrous; Europe and E. North America.................................................................................................................................................................... <i>N. ovina</i></p> <p> 6’. Pileus smaller, with a pale grey margin; basidiospores shorter, 5.5–8 µm long; large pseudocystidia present; odour absent; Puerto Rico, Caribbean............................................................................................................................................................... <i>N. ovinoides</i></p> <p>7. Odour none.........................................................................................................................................................................................8</p> <p>7’. Odour unpleasant, nitrous or farinaceous.........................................................................................................................................11</p> <p> 8. Large pseudocystidia absent in hymenium; pileipellis terminal hyphal elements swollen, subclavate to subglobose; in Australia......................................................................................................................................................................... <i>Hygrocybe badioclavata</i></p> <p>8’. Characters different, large pseudocystidia present; pileipellis hyphal ends not swollen...................................................................9</p> <p> 9. Pileus vinaceous brown, pale margin, small (2–8 mm); Caribbean........................................................... <i>Hygrocybe albomarginata</i></p> <p>9’. Pileus grey-brown to black, lacking a pale band on margin large (20-45 mm); South Pacific........................................................10</p> <p> 10. Spores small, 6.5–7.5 × 4.5–5.5 µm; in New Zealand.................................................................................................... <i>N. squarrosa</i> 10’. Spores larger, 7–9.5 × 5.5–7 µm; in Hawaii......................................................................................................... <i>Hygrocybe waolipo</i></p> <p>11. Large pseudocystidia present in hymenium.....................................................................................................................................12</p> <p>11’. Pseudocystidia absent in hymenium.................................................................................................................................................13</p> <p> 12. Stipe slender, 5–7 mm wide; pileipellis hyphae encrusted; Brazil...................................................................................... <i>N. fumosa</i></p> <p> 12’. Stipe swollen, 8–32 mm wide; pileipellis hyphae not encrusted; Europe................................................................ <i>N. pseudoingrata</i></p> <p> 13. Pileus sooty brown; odour farinaceous; in Australia........................................................................... <i>Hygrocybe fuligineosquamosa</i></p> <p>13’. Pileus warmer colour, grey- orange- or golden-brown; odour nitrous.............................................................................................14</p> <p> 14. Pileus perforated in centre; in Sri Lanka, India.............................................................................................. <i>Hygrocybe cinerascens</i></p> <p> 14’. Pileus not perforated in centre; in Europe, Iceland.............................................................................................................. <i>N. nitrata</i></p>Published as part of <i>Cardoso, Juli Simon, Moncalvo, Jean-Marc, Lodge, D. Jean, Margaritescu, Simona, Neves, Maria Alice & Oliveira, Jadson J. S., 2023, Studies in Hygrocybe s. l. (Hygrocyboideae, Hygrophoraceae) in Brazil: New species of Humidicutis and Neohygrocybe, pp. 57-71 in Phytotaxa 607 (1)</i> on pages 68-69, DOI: 10.11646/phytotaxa.607.1.5, <a href="http://zenodo.org/record/8212211">http://zenodo.org/record/8212211</a&gt

Podoplanin expression in tumor-free resection margins of oral squamous cell carcinomas: an immunohistochemical and fractal analysis study

Podoplanin is involved in tumorigenesis and cancer progression in head and neck malignancies and its expression is not restricted to lymphatic vessel endothelium. The aim of this study was to establish podoplanin expression in the tumor-free resection margins of oral squamous cell carcinomas (OSCCs) and to evaluate the geometric complexity of the lymphatic vessels in oral mucosa by utilizing fractal analysis. As concerns the podoplanin expression in noncancerous tissue, forty tumor-free resection margins from OSCCs were investigated utilizing immunohistochemistry for D2-40 antibody and image densitometry analysis. Podoplanin expression was extremely low in basal cells, especially in resection margins of OSCCs developed in the lower lip regions. However, a highly variable D2-40 expression in tumor-free resection margins associated with hyperplastic or dysplastic lesions was identified. Moreover, podoplanin expression also extended to the basal layer of the lower lip skin appendages, the myoepithelial cells of acini and ducts of minor salivary glands, and other structures from the oral cavity. As concerns the study of the density and complexity of oral lymphatic vessels architecture by means of immunohistochemistry (D2-40, CD31 and Ki-67 antibodies) and fractal analysis, we demonstrated that in normal oral mucosa the geometry of the lymphatic vessels was less complex at the level of the lower lip compared to the anterior part of the oral floor mucosa or the tongue. A comparative analysis between the normal and pathological aspects revealed statistically significant differences between the fractal dimension (FD) of the vessels’ outline, especially in the tongue. Fractal analysis proved an increasing lymphatic network complexity from normal to premalignant oral mucosal lesions, providing additional prognostic information in oral malignant tumor