This is from a 76-year-old male with a fungating maxillary antral mass that extends into the nasal cavity. (Author)
CARCINOSARCOMA

A 23-year-old woman underwent left thyroid lobectomy and isthmusectomy for a 2 cm diameter firm mass on the left side of the neck that was also visualized on ultrasonography. The specimen consisted of a 22-gram thyroid gland composed of the left lobe, isthmus and a pyramidal lobe. Cut section of the left lobe showed a 3.5 cm diameter solitary, discrete and encapsulated mass with a tan lobulated and solid cut surface. The rest of the thyroid tissues had red-brown meaty cut surfaces. Microscopic section shows a follicular-patterned proliferation enclosed by a thin fibrous capsule with frequent Sanderson polster-like papillary excrescences. (Figures 1 and 2) Both the follicular and the papillary structures are lined by cuboidal to columnar follicular epithelial cells that had ample eosinophilic to pale cytoplasm and uniformly sized, minimally enlarged, generally round, and monolayered nuclei without nuclear grooving, folds, pseudoinclusions, and chromatin clearing. There are no mitotic figures seen. Some of the papillary structures have delicate vascular cores. (Figure 3) There are no psammoma bodies noted. The follicles contain variable amounts of pale eosinophilic colloid ranging from colloid-poor crowded follicles to those with ample colloid that have frequent peripheral scalloping. (Figure 4) Exhaustive sections failed to disclose capsular or vascular invasion. Based on the microscopic features, a diagnosis of follicular adenoma with papillary architecture was rendered.
Follicular thyroid carcinoma ; papillary thyroid carcinoma

MAXILLA

A 65-year-old male with a two-month history of cough and hoarseness underwent direct laryngoscopy which showed a 1.5 cm diameter polypoid glottic mass. A polypectomy was performed revealing spindle cell carcinoma. The World Health Organization (2005) defines a spindle cell carcinoma as “a biphasic tumor composed of a squamous cell carcinoma, either in-situ and/or invasive, and a malignant spindle cell component with a mesenchymal appearance, but of epithelial origin.”1 Spindle cell carcinomas go by a variety of synonyms such as sarcomatoid carcinoma, spindle cell squamous carcinoma and carcinosarcoma. The larynx is a preferred site of involvement where they often present as polypoid masses.1,3 Microscopic examination often shows predominance of the sarcomatoid, spindle-cell component, which can range from fairly bland, reactive-looking fibroblastic-proliferation-like processes, to cytologically malignant and mitotically active proliferations that mimic other spindle-cell sarcomas such as leiomyosarcoma, fibrosarcoma or malignant fibrous histiocytoma.1,2,3 (Figure 1, double arrows) The squamous cell carcinoma component may be in the form of an overlying carcinoma-in-situ, or of a focal keratinizing invasive squamous cell carcinoma that requires multiple sections to disclose.1,2 (Figure 1, single arrow) Cytokeratin-reactivity in the spindle cells, which may be quite focal as in this case, points to their epithelial derivation.1,2,4 (Figure 2) Favorable prognostic findings include polypoid morphology and, like conventional laryngeal squamous cell carcinomas, a low-stage and a glottic site of origin. Reported 5-year survival rates range from 65 – 95%.
Human ; Male ; Aged ; Carcinoma ; Head and Neck Neoplasms

This is the case of a 44-year-old woman with a one-year history of a left pre-auricular mass. The surgical specimen is a 5 centimeter diameter tan-brown irregularly-shaped tissue whose cut surfaces are brown with cystic spaces. Microscopic sections show cystic and dilated ductal spaces lined by cells forming irregular, variably-sized secondary spaces. These spaces are arranged in a cribriform pattern that is reminiscent of breast ductal hyperplasia. (Figure 1) The ductal cells lining the spaces are small, multilayered, and generally bland. The superficial cells show apocrine-type cytoplasmic snouting. There is no significant nuclear atypia or mitotic activity noted. Necrosis is also absent. (Figure 2) Based on these features, we signed the case as a low-grade cribriform cyastadenocarcinoma (LGCCC).
Human ; Male ; Adult ; Hyperplasia ; Cysts ; Parotid Gland ; Cystadenocarcinoma ; Necrosis

A 37-year-old woman consulted for a slow-growing mass of one-year duration on the left side of the mandible with associated tooth mobility. Clinical examination showed buccal expansion along the left hemi-mandible from the mid-body to the molar-ramus region with associated mobility and displacement of the pre-molar and molar teeth. Radiographs showed a well-defined unilocular radiolucency with root resorption of the overlying teeth. Decompression and unroofing of the cystic lesion was performed. Received in the surgical pathology laboratory were several gray-white rubbery to focally gritty tissue fragments with an aggregate diameter of 1 cm. Histopathologic examination shows a fibrocollagenous cyst wall lined by a fairly thin and flat stratified squamous epithelium without rete ridges. (Figure 1) The epithelium is parakeratinized with a wavy, corrugated surface while the basal layer is cuboidal and quite distinct with hyperchromatic nuclei. (Figure 2) Based on these features, we signed the case out as odontogenic keratocyst (OKC). Odontogenic keratocysts are the third most common cysts of the gnathic bones, comprising up to 11% of all odontogenic cysts, and most frequently occurring in the second to third decades of life.1,2 The vast majority of cases occur in the mandible particularly in the posterior segments of the body and the ramus. They typically present as fairly large unilocular radiolucencies with displacement of adjacent or overlying teeth.1 If associated with an impacted tooth the radiograph may mimic that of a dentigerous cyst.2 Microscopically, the parakeratinized epithelium without rete ridges, and with a corrugated luminal surface and a prominent cuboidal basal layer are distinctive features that enable recognition and diagnosis.1,2,3 Occasionally, smaller “satellite” or “daughter” cysts may be seen within the underlying supporting stroma, sometimes budding off from the basal layer. Most are unilocular although multilocular examples are encountered occasionally.1 Secondary inflammation may render these diagnostic features unrecognizable and non-specific.2 Morphologic differential diagnoses include other odontogenic cysts and unicystic ameloblastoma. The corrugated and parakeratinized epithelial surface is sufficiently consistent to allow recognition of an OKC over other odontogenic cysts, while the absence of a stellate reticulum and reverse nuclear polarization will not favor the latter diagnosis.2,3 Odontogenic keratocysts are developmental in origin arising from remnants of the dental lamina. Mutations in the PTCH1 gene have been identified in cases associated with the naevoid basal cell carcinoma syndrome as well as in non-syndromic or sporadic cases.1,3 These genetic alterations were once the basis for proposing a neoplastic nature for OKCs and thus the nomenclature “keratocystic odontogenic tumor” was for a time adopted as the preferred name for the lesion.3,4 Presently, it is felt there is not yet enough evidence to support a neoplastic origin and hence the latest WHO classification reverts back to OKC as the appropriate term.1 Sekhar et al. gives a good review of the evolution of the nomenclature for this lesion.3 Treatments range from conservative enucleation to surgical resection via peripheral osteotomy.5 Reported recurrences vary in the literature ranging from less than 2% of resected cases up to 28% for conservatively managed cases.1,5 These are either ascribed to incomplete removal or to the previously mentioned satellite cysts - the latter being a feature associated with OKCs that are in the setting of the naevoid basal cell carcinoma syndrome.1,2,3 Thus, long term follow-up is recommended.5 Malignant transformation, though reported, is distinctly rare.
odontogenic cyst ; odontogenic tumors ; Basal Cell Nevus Syndrome

A 70-year-old man consulted for a mass of unspecified duration in the anterior area of the mandible. Radiologic information was not provided. An incision biopsy was performed by the dentistry service. The specimen received at the laboratory was labeled “cystic lining” and consisted of two light-gray to dark brown, irregularly shaped tissue fragments measuring 0.3 cm and 0.4 cm in diameters.
Odontogenic Cysts

This is a case consult of slides stated to be from an excision of a buccal mucosa mass in a 58-year-old-man. The specimen was described as a 3 cm diameter roughly oval tan-gray tissue with a 2 x 1.5 cm mucosal ellipse on the surface that has a central ulcerated punctum. Cut section showed an underlying 1.7 cm diameter roughly oval well-circumscribed mass with a granular tan surface. Histological sections show a papillary lesion with an orifice on the mucosal surface and with epithelial nests invaginating into the underlying lamina propria in a non-infiltrative pattern. (Figure 1) The lesion is composed of papillary epithelial fronds with cleft-like spaces between the fronds. (Figure 2) The papillary fronds are lined by non-keratinizing basaloid stratified squamous cells with a superficial layer of columnar glandular cells along with mucous goblet cells interspersed among the squamous cells. (Figure 3) All the cellular components are devoid of cytologic atypia and mitoses. Based on these microscopic features we signed the case out as inverted ductal papilloma (IDP).
Papilloma, Intraductal ; Salivary Glands

The World Health Organization (2005) defines an epithelial-myoepithelial carcinoma (EMC) as a malignancy composed of two cell types that typically form duct-like structures.1 We present herein an archival case from the parotid gland. EMC occurs primarily in the major salivary glands particularly in the parotid where it presents as a painless, slow-growing mass.1 Microscopic examination shows bi-layered tubular duct-like structures with pale to clear areas (Figure 1). The inner luminal layer is composed of cuboidal cells that are of epithelial derivation while the outer layer is composed of polygonal cells that are of myoepithelial derivation (Figures 2 and 3). The latter typically have abundant clear cytoplasm.1,2 The epithelial-myoepithelial dualism is confirmed using immunohistochemical stains; the epithelial cells being immunoreactive for low molecular weight keratin and the myoepithelial cells for S-100 protein, muscle specific actin, vimentin and p63.1, 3 EMC is primarily a tumor of adulthood with peak incidence in the sixth and seventh decades. First described by Donath et al. in 1972,3 they are rare salivary gland neoplasms with an incidence of less than 1% arising mainly in the parotid gland4 although they have been documented in the lungs.5 Perineural and vascular invasion are frequent and recurrence occurs in around 40% of cases and metastasis in 14%.1 Although thought to be of low-grade malignancy, fatal courses have been described4 and “analysis of the various series have demonstrated that tumors with a solid growing pattern, nuclear atypia, DNA aneuploidy and high proliferative activity, generally have a more aggressive behavior and a higher frequency of local recurrences and metastases.”3
Human ; Carcinoma

A case of melanotic neuroectodermal tumor of infancy (MNETI) is presented. The salient histopathologic features of this unusual neoplasm are discussed including post-chemotherapy morphologic changes.
Neoplasms