Sialadenoma papilliferum with potentially malignant features.

Sialadenoma papilliferum (SP) is a benign non-invasive lesion with slow and limited growth. This report describes an unusual SP that enlarged rapidly and presented as an extensive intraoral tumour highly suspicious for verrucous carcinoma. Radiographic resorption of the underlying bone was evident in the mandible. This type of destructive growth does not conform to any previously reported SP. Histological features were also atypical: surface verrucous hyperplasia and deeper florid cystic-duct adenoma. Overall, the SP is likely to be considered a borderline lesion with malignant potential. Four published cases of malignancy associated with SP showed completely different clinical and pathological settings, further obfuscating the concept of malignant SP.

Oral administration of cilnidipine to patients with hypertensive intracerebral hemorrhage in the acute stage: significance and role of an N-type calcium channel blocker.

BACKGROUND: Elevated blood pressure (BP) causes rebleeding or enlargement of intracerebral hematomas. AIMS: How a long-acting oral calcium channel blocker, cilnidipine, could control BP in the acute stage of cerebral hemorrhage was evaluated. METHODS AND RESULTS: Cilnidipine given within 3 days of hospitalization has more benefit than cilnidipine given after 4 days of hospitalization; it can reduce the amount of intravenous nicardipine, and it can help to maintain the BP below 80% of the initial BP. Surgical removal of the hematoma has no benefit in reducing the amount of intravenous nicardipine and maintaining the BP below 80% of the initial BP. CONCLUSION: In order to reduce the total amount of intravenous nicardipine and to maintain the BP below 80% of the initial BP, oral administration of a long-acting N-type calcium channel blocker, cilnidipine, is useful and important, independent of whether the hematomas are surgically removed.

Cellular basis of verruciform xanthoma: immunohistochemical and ultrastructural characterization.

BACKGROUND: Verruciform xanthoma (VX) holds two basic pathogenic interests: (1) Why and how do macrophage foam cells accumulate exclusively in the sub-basal papillae? and (2) What underlies the disease chronicity? Moreover, an unsolved question is which came first - epithelial hyperplasia or foam cell collection? MATERIALS AND METHODS: We analyzed 36 oral mucosal lesions to dissect a series of linked cellular changes in VX using immunohistochemical and ultrastructural techniques. RESULTS: Macrophage scavenger receptor-1 (MSR-1), monocyte chemoattractant protein-1 (MCP-1), CCR2, and oxidized low-density lipoprotein (ox-LDL) were all expressed by foam cells. VX epithelium showed reactivity for MCP-1, HLA-DR and IL8 in varying degrees, and showed a nearly 40% reduction in Langerhans cell density. In sub-epithelial inflammatory infiltrates, CD8+ T cells preponderated (>70%), but only a minority were positive for granzyme B (<1%). Keratinocyte/basal lamina complex exhibited disruption of basal lamina, squamatization and cytolysis of basal cells, fragmentation of desmosomes, and intraepithelial migration of macrophages. In severely inflamed papillae, necrotic foam cells were scavenged by adjacent macrophages. CONCLUSIONS: Under synergistic regulation of T cells, MCP-1/CCR2-mediated macrophage recruitment in the sub-basal papillae and the lysosomal engulfment of epithelial lipids by MSR-1-bearing macrophages may be central in VX formation. Once developed, ox-LDL-induced foam cell necrosis and macrophage-dependent debris disposal may cyclically perpetuate VX.

Unsuspected small ameloblastoma in the alveolar bone: a collaborative study of 14 cases with discussion of their cellular sources.

BACKGROUND: Intraosseous ameloblastoma (IA) is the quintessence of epithelial odontogenic tumor and histologically and behaviorally defined as an undoubted neoplastic process. Current information must lead to the consensus that IA arises from the embryologic inclusions of odontogenic epithelium within the jawbone. Nevertheless, clinically oriented evidence is limited to this day. METHODS: The clinical and radiographic features, behavior, and pathology of 14 cases of small IA confined to the alveolar region were systematically examined. RESULTS: Six cases were a chance finding. There was no gender predilection and half of the lesions clustered in middle age (>40 years). The posterior region of the mandible (n = 7) and the anterior segment of the maxilla (n = 4) were favored. Five radiographic characteristics were recognized: interradicular (n = 5) and periradicular (n = 3), and periapical, residual and pericoronal (n = 2 each). They showed solid (n = 12) or unicystic (n = 2) growth pattern and 12 lesions were divided into seven follicular, three desmoplastic, and two plexiform subtypes. The main location of tumor was microscopically traceable in six cases; three interradicular type outside the periodontal ligament space and two periradicular and one periapical variants inside. CONCLUSION: By in-depth evaluation of the spatial relationship between tumor and its surrounding structure, the alveolar process, periodontal ligament space, and pericoronal area are all the likely starting points of IA. This report re-awakens the oral pathologist to the histogenetic significance of incipient IA as the only available human specimen for reappraisal of their origin.

Two unusual vascular lesions: epithelioid angiomatous nodule and spindle cell hemangiomatosis.

This report outlines the pathologic findings of epithelioid angiomatous nodule and spindle cell hemangiomatosis and briefly discusses the list of differential diagnoses. Although prevalent in the skin, both the above acquired vascular lesions are rarely described in the oral cavity. It should be realized that their microscopic features often raise concern for malignancy.

Perivascular myoid tumors of the oral region: a clinicopathologic re-evaluation of 35 cases.

BACKGROUND: Myopericytoma (MPC) is a generic denomination to describe tumors showing differentiation toward perivascular myoid cells /myopericytes. It has been suggested that MPC forms a morphologic continuum with glomus tumor (GT), solitary myofibroma (SMF), and angioleiomyoma (ALM). This proposed relationship has not yet been assessed in the oral region. METHODS: We reviewed our 28-year experience with 35 oral tumors, originally diagnosed as ALM (n = 28), SMF (n = 4), GT (n = 2), and MPC (n = 1) to analyze their overlapping microscopic features, with the assistance of immunohistochemistry. RESULTS: Myopericytoma showed a wide range of growth patterns; concentric perivascular whorls, hemangiopericytomatous areas, glomangiopericytoma (GPC)-type vessels and leiomyomatous foci. Intravascular growth was also seen. Among 28 cases studied, three ALM were reclassified as MPC (n = 2) and SMF (n = 1), based on the present diagnostic criteria. Additional MPC-type components, at varying degrees, were similarly found in four ALM and three SMF, at least focally. One GT featured intravascular whorls of spindle cells. These four interrelated groups of tumors had in common GPC-type vasculature and intraluminal cellular proliferation was nearly ubiquitously present. Diffuse immunoreactivity for alpha-smooth muscle actin and less staining intensity of muscle-specific actin were observed in all tumors. Only ALM displayed desmin positivity of variable extent. Neither case tested expressed CD34. CONCLUSIONS: Our data matches with the recent results in extraoral sites that MPC, GT, SMF, and ALM exhibit histologic and immunohistochemical overlap with each other. A common perivascular myoid differentiation between these tumor types is further reinforced by the present oral series.

Neurotized nevi of the oral mucosa: an immunohistochemical and ultrastructural analysis of nevic corpuscles.

BACKGROUND: Nevic corpuscle (NC), a stacked lamellar structure reminiscent of Meissner corpuscle, is frequently observed in dermal melanocytic nevi. Although the heading 'neurotized' is classically used for these nevi, the exact neural nature of NC has been a topic of considerable debate. Neurotized nevi have received little attention in the dental literature, and there was no information on NC in oral melanocytic nevi. METHODS: Six cases of oral intramucosal nevi with a significant number of NC (two completely and four partially neurotized nevi) were examined immunohistochemically and ultrastructurally. RESULTS: NC was composed of closely piled laminar cells devoid of visible melanin. NC and associated spindle nevus cells were immunopositive for S-100 protein but negative for HMB-45, myelin basic protein and epithelial membrane antigen. Within NC, no reactivity for neurofilament protein, protein gene product 9.5 or peripherin was evident. Numerous CD34-positive dendritic cells were located between nevus cells and often encircled NC. Ultrastructurally, NC consisted of concentrically layered elongated cells with a slender lamellated cytoplasm rich in thin filaments and pinocytotic vesicles. Their cytoplasmic processes were focally covered by external basal lamina and continuous to spindle nevus cells. Occasional NC cells contained a few melanosomes. There was no interposed axon in NC. CONCLUSIONS: Despite the close resemblance to Meissner corpuscle, NC showed no axonal supply. NC cells lacked terminal Schwannian differentiation and appeared to be modified melanocytes with some perineurial ultrastructural characteristics. The presence of CD34-positive cells, presumably corresponding to endoneurial fibroblasts, further supports an organizational relationship of NC and peripheral nerve sheath elements.

Hamartomatous proliferations of odontogenic epithelium within the jaws: a potential histogenetic source of intraosseous epithelial odontogenic tumors.

BACKGROUND: The jawbone is replete with a vestige of odontogenesis. The overall consensus is that intraosseous remnants of the enamel organ and dental lamina are the only histogenetic option for central epithelial odontogenic tumors. Curiously, incipient tumors or possible precursor conditions of residual odontogenic epithelium have rarely been reported in the literature. METHODS: We microscopically evaluated 39,660 biopsy samples to determine the presence of a tumor-like odontogenic epithelial nodule in the maxilla and mandible. RESULTS: Seven intraosseous specimens that associated with a focal proliferation of odontogenic epithelium were retrieved. Six hamartomatous processes showed four different morphologic patterns comparable with the tumor nests comprising ameloblastoma (n = 1), squamous odontogenic tumor (n=1), calcifying epithelial odontogenic tumor (n=2) and calcifying cystic odontogenic tumor (n=2). Among six lesions, four were the intrafollicular development. The remaining case of interest was multiple hyperplastic clear rests of Malassez in association with an impacted tooth. CONCLUSION: Although it is impossible to predict the fate of these microscopic structures of hamartomatous character, the present case series indicates that any of the dormant embryonic residues of odontogenic epithelium can return to an active state, capable of non-reactive, probably neoplastic proliferation of pathological significance.

Further evidence for adipocytic differentiation by the neoplastic myoepithelium.

Lipomatous pleomorphic adenoma (PA)/myoepithelioma is rare. Nevertheless, adipocytic differentiation in salivary gland tumors is a well-known phenomenon. As extensive lipometaplasia occurs primarily in adenomas with myoepithelial participation, circumstantial evidence implicates neoplastic myoepithelium (NME), especially the spindle type, as a key partaker. We report here a unique PA that represents an equivocal transition from the epithelioid NME to adipocytes in recurrent lesions but not in a primary tumor.

Pacinian neuroma in adipose herniation of the buccal mucosa.

An interesting case of a trauma-induced tender mass of the buccal mucosa in a 45-year-old man was presented. Following surgery, the patient was relieved from pain. Microscopically, the mature adipose tissue is unique in that it contained a single enlarged Pacinian corpuscle near the deep margin. This is the hitherto undescribed intraoral lesion of Pacinian neuroma in the herniated buccal fat pad.

Intraparotid pseudoglandular schwannoma.

A unique intraparotid location of a rare pseudoglandular schwannoma is described. Although the diagnosis of schwannoma could readily be substantiated, accurate subtyping was initially mislabeled. The pitfall was in failing to acknowledge the presence of multiple well-formed gland-like structures, which is instantly thought to be cystically dilated salivary ducts. Immunohistochemically, epithelial-appearing cells lining the duct-like spaces proved to be schwannian in nature. Interpretation of an immediately recognizable gland-like architecture is more problematic when a pseudoglandular variant originates from a nerve coursing through the gland, as here.

Peripheral odontogenic tumor: a clinicopathologic study of 30 cases. General features and hamartomatous lesions.

BACKGROUND: Peripheral odontogenic tumors (POT), either neoplastic or hamartomatous, are rare. This study briefly summarizes the general features of POT and selectively reviews the histomorphologic spectrum of under-recognized hamartomatous lesions that we have designated peripheral odontogenic hamartomas (POH) in order to shed more light into the pathogenesis of POT. METHODS: Archival material accessioned at our institutions between 1970 and 2004 was systematically searched to identify examples of POT/POH. RESULTS: Among 39 660 biopsies, we retrieved 25 cases of 'classical' POT and five cases of 'unique' POH. Odontogenic fibroma and ameloblastoma were by far the most common. Of POH, two purely epithelial lesions showed multiple strands of basaloid rests [odontogenic gingival epithelial hamartoma (OGEH)] and a conglomerate of polyhedral epithelium, ghost cells and concentric calcifications (calcifying epithelial odontogenic tumor-like hamartoma), respectively. OGEH and peripheral squamous odontogenic tumor (PSOT) deserve to be a related entity. In two types of mixed POH, ectomesenchymal elements appeared juxtaposed to the squamous lining (gingival cyst-like organoid hamartoma) and ghost cells aggregated in the enamel organ of a microdont (peripheral odontoma). None of POH exhibited continuity with the surface epithelium. CONCLUSION: On the basis of this relatively limited series of cases, POH, to conceptualize a unified histogenetic source, are speculated to arise from the soft-tissue remnants of dental lamina. Gingival rests of Serres seem to retain the ability to pursue epithelial-ectomesenchymal interactions that are necessary leading to odontoma formation.

Ameloblastoma ex calcifying odontogenic cyst (dentinogenic ghost cell tumor).

Calcifying odontogenic cyst (COC) has shown to be of extensive diversity in its clinical and histopathological features, as well as in its biological behavior. In this report, a rare case is described of ameloblastoma ex COC (dentinogenic ghost cell tumor) and the relevant literature is briefly reviewed.

Collagenous fibroma (desmoplastic fibroblastoma): a new case originating in the palate.

A 49-year-old woman presented with a painless slowly growing but huge polypoid palatal mass. On magnetic resonance imaging (MRI), areas of low signal intensity were consistent with a fibrous tumour. T(1) and T(2) weighted MRI after Gd-DTPA administration highlighted a well-circumscribed, purely soft tissue process. Histological analysis of the operative specimen detected collagenous fibroma (desmoplastic fibroblastoma). The patient remains disease-free 4 years after excision.