Chronic kidney disease-mineral bone disorder: an update on the pathology and cranial manifestations.

Chronic kidney disease-mineral bone disorder (CKD-MBD) is a syndrome encompassing skeletal and extra skeletal changes associated with chronic kidney disease. It progresses silently until an advanced clinical stage when complications impact on the quality of life and survival rates of patients. The maxillofacial manifestations are unique and may play an important role in the early identification of changes which could influence the management of these patients. The goal of this review is to highlight the maxillofacial features, pathology, and principles of management of CKD-MBD.

Stable isotope series from elephant ivory reveal lifetime histories of a true dietary generalist.

Longitudinal studies have revealed how variation in resource use within consumer populations can impact their dynamics and functional significance in communities. Here, we investigate multi-decadal diet variations within individuals of a keystone megaherbivore species, the African elephant (Loxodonta africana), using serial stable isotope analysis of tusks from the Kruger National Park, South Africa. These records, representing the longest continuous diet histories documented for any extant species, reveal extensive seasonal and annual variations in isotopic--and hence dietary--niches of individuals, but little variation between them. Lack of niche distinction across individuals contrasts several recent studies, which found relatively high levels of individual niche specialization in various taxa. Our result is consistent with theory that individual mammal herbivores are nutritionally constrained to maintain broad diet niches. Individual diet specialization would also be a costly strategy for large-bodied taxa foraging over wide areas in spatio-temporally heterogeneous environments. High levels of within-individual diet variability occurred within and across seasons, and persisted despite an overall increase in inferred C(4) grass consumption through the twentieth century. We suggest that switching between C(3) browsing and C(4) grazing over extended time scales facilitates elephant survival through environmental change, and could even allow recovery of overused resources.

Plasmablastic lymphomas with light chain restriction - plasmablastic extramedullary plasmacytomas?

BACKGROUND: It is diagnostically difficult to differentiate plasmablastic lymphomas (PBLs) from plasma cell neoplasms with plasmablastic differentiation. Plasmablastic lymphomas are currently classified as 'PBL of the oral mucosa' and 'PBL with plasmacytic differentiation'. METHODS: Forty-five cases of PBL were retrieved from the Departments of Oral Pathology of the Universities of Pretoria and Limpopo, South Africa. Clinical features and HIV status were recorded and each case was classified as 'PBL of the oral mucosa type' or as 'PBL with plasmacytic differentiation'. Immunohistochemistry included: CD45, CD3, CD20, CD79a, CD38, CD138, MUM1, Ki-67 and kappa and lambda light chains. Positivity was recorded based on the percentage of positive staining cells as focal (5-20%); intermediate (20-70%) or diffuse (>70%). In situ hybridization was performed for Epstein-Barr virus (EBV) and HHV-8. Results were recorded as positive or negative. RESULTS: All cases showed some degree of plasmacytic differentiation. All were negative for CD20 with reactive T cells detected with CD3. Diffuse and strong positive staining was found with Ki-67 and MUM1, but variable immunoreactivity was found with CD79a, CD45, CD38 and CD138. Twenty cases (47%) showed light chain restriction. Epstein-Barr virus was detected in 44/45 cases and HHV-8 in none. CONCLUSIONS: The morphological classification of PBLs is not valid as all cases showed some degree of plasmacytic differentiation. We propose that PBLs with light chain restriction be reclassified as 'plasmablastic extramedullary plasmacytomas' and managed accordingly. The rest represents true PBLs. The true nature of these neoplasms as an entity should be further investigated with molecular and genetic studies.

Calretinin expression in the differential diagnosis of human ameloblastoma and keratocystic odontogenic tumor.

Ameloblastoma is a benign, locally aggressive epithelial odontogenic tumor that has the potential to become malignant and produce metastasis to distant sites such as lungs and kidneys. The histologic presentation can be, in some instances, mistaken for keratocystic odontogenic tumor (KCOT) (formerly known as odontogenic keratocyst). The expression of calretinin [calbindin2 (CALB2)] was investigated on both ameloblastoma and KCOT. Nineteen cases of ameloblastoma and 17 cases of KCOT were stained with calretinin antiserum 18-0211 (Zymed, San Francisco, CA). All cases (100%) of ameloblastoma showed positive calretinin staining, restricted to the neoplastic epithelial component and none (0%) of the 17 KCOTs showed positive calretinin staining. Gene expression profiling of ameloblastomas showed CALB2 expressed in the basal cell layer of columnar cells resembling preameloblasts, in all 5 of the ameloblastomas evaluated. Taken together, the results of this study strongly support calretinin as a useful immunohistochemical marker for ameloblastoma and malignant ameloblastoma and it can also be used in the differential diagnosis of KCOT.

Human immunodeficiency virus-associated Kaposi sarcoma as an immune reconstitution inflammatory syndrome: a literature review and case report.

BACKGROUND: Kaposi sarcoma (KS) is the most common human immunodeficiency virus (HIV)-associated neoplasm (HIV-KS). Highly active antiretroviral therapy (HAART) results in a decrease in the incidence and prevalence of HIV-KS as well as in clinical improvement. However, in a subset of subjects who are HIV seropositive, KS may recrudesce early following the introduction of HAART as an immune reconstitution inflammatory syndrome (IRIS). METHODS: The management of a patient who is HIV seropositive with rapid clinical worsening of oral KS lesions shortly after the initiation of HAART was documented. Repeated serologic testing for CD4(+) T-cell count and microscopic examination of two biopsy specimens of the oral lesion, one taken before and the other taken after cytotoxic chemotherapy, followed by surgical excision was the treatment modality used. RESULTS: Microscopic examination of the incisional biopsy specimen taken from the oral lesion at the time of the initial consultation confirmed the clinical diagnosis of KS. The sequential serological tests showed a progressive increase in CD4(+) T-cell counts that paralleled the rapid clinical worsening of the KS disease. This was consistent with the diagnosis of IRIS-associated HIV-KS. Subsequent cytotoxic chemotherapy brought about resolution of the IRIS and regression of the HIV-KS lesions. Microscopic examination of a biopsy specimen obtained after cytotoxic chemotherapy did not show any of the original KS. The residual palatal exophytic mass was excised. CONCLUSIONS: IRIS-associated HIV-KS is not a disease, but rather a temporary paradoxical immunoinflammatory reaction brought about by improvement in immune status following HAART. IRIS-associated HIV-KS can be controlled effectively by limited systemic cytotoxic chemotherapy in the setting of HAART.

Human immunodeficiency virus (HIV)-associated extranodal T cell non-Hodgkin lymphoma of the oral cavity.

T cell non-Hodgkin lymphoma is characterized by uncontrolled cellular proliferation of immature malignant clones. HIV-associated T cell non-Hodgkin lymphoma comprises a heterogeneous group of lymphoproliferative neoplastic entities classified according to morphological, immunological, genetic and clinical features. Extranodal T cell non-Hodgkin lymphoma of the oral cavity is uncommon. A case is presented with extranodal T cell non-Hodgkin lymphoma as an initial sign of HIV-infection. The characteristics of HIV-associated non-Hodgkin lymphoma are discussed.

Mixed adenoneuroendocrine carcinoma of the tongue arising within a congenital enteric cyst.

BACKGROUND: Primary intestinal-type adenocarcinoma of the tongue is rare. This represents the first reported case of a primary mixed adenoneuroendocrine carcinoma (MANEC) of the tongue arising within a congenital enteric cyst. METHODS: A 52-year-old man presented with a midline tongue mass that was connected to the mucosal surface with an epithelial-lined sinus tract. Morphological examination and immunohistochemical profiling of the neoplasm were performed. RESULTS: Histopathological evaluation showed a primary MANEC arising within a preexisting congenital enteric cyst, comprising both adenocarcinoma and neuroendocrine components. The adenocarcinoma had a colonic-type morphology and coexpressed CK7, CK20, and CDX2. Imaging and colonoscopy excluded a distant primary colorectal neoplasm. CONCLUSION: The association of primary MANEC of the tongue with a gastrointestinal heterotopic cyst supports an origin from entrapped endodermal elements as opposed to salivary duct origin. This case raises the awareness of a rare yet prognostically important complication of a gastrointestinal heterotopic cyst.

HIV-associated oral Kaposi sarcoma and HHV-8: a review.

Kaposi sarcoma is the most common malignant tumour associated with HIV infection. In the majority of cases oral tissues are involved and in 22% the initial presentation is in the oral cavity. The oral lesions are either single or multifocal, and the palate, gingiva and tongue are the sites most frequently involved. The pathogenesis of Kaposi sarcoma in HIV-seropositive subjects is complex. It involves interaction between human herpesvirus-8 (HHV-8) and HIV, altered cellular signal transduction pathways, and increased production of cytokines and growth factors. The multifactorial nature and clinical stages in the growth of oral Kaposi sarcoma are discussed.

Primary malignant melanoma of the vermilion of the lip.

Malignant melanoma of the vermilion of the lip is a rare entity, and because of the common occurrence of other benign pigmented lesions, it is easily overlooked. Early diagnosis is of the utmost importance, in the first instance to minimise the risk of haematogenous, lymphatic, perineural and trans- (salivary) ductal spread. The second reason for early diagnosis is that surgery is the only effective form of treatment. A number of important clinical lessons were learned from this cohort study of malignant melanoma of the vermilion of the lip. Two observations are of note--first, the absence of palpable regional lymph nodes does not exclude the presence of a malignant melanoma, yet all patients presenting with palpable nodes were suffering from a preterminal disease. Secondly, apart from 1 case (our case 2), melanoma of the lip seems to occur on the lower lip only. There are no clear guidelines regarding the necessary extent of extirpation for malignant melanoma of the vermilion of the lip, but we propose that clear margins of less than 10 mm are probably inadequate and margins of more than 20 mm are unnecessary. Concern about a resection resulting in a 20 mm clear margin all round is seldom justified as excellent methods of reconstruction achieving acceptable mobile, adequately sensate lips are available.

Proliferative verrucous leukoplakia and field cancerization: report of a case.

Proliferative verrucous leukoplakia (PVL) is a multi-focal oral pre-malignant lesion, proliferative in nature, with a tendency to recur despite adequate therapy, and a high rate of malignant transformation. The field cancerization phenomenon may explain the characteristic behaviour of PVL. A case of PVL is presented and the field cancerization concept is discussed.

Complex oral manifestations of an HIV-seropositive patient.

A complex manifestation of characteristic oral lesions occurring simultaneously in an HIV-seropositive patient is presented. Necrotizing ulcerative gingivitis (NUG), necrotizing ulcerative periodontitis (NUP), oral-facial herpes infection, pseudomembranous candidiasis and atypical oral ulceration are discussed. In spite of extremely low CD4+ T-cell counts of 3 x 10(6)/L and lack of anti-retroviral therapy, an AIDS patient responded favourably to standard periodontal therapy. In the follow-up period of 3 months, no recurrence of any of the oral lesions initially present occurred and no special prophylactic regimes were needed to maintain oral health. This case illustrates that appropriate management of the oral manifestations contributes significantly to improvement of the quality of life of patients in the terminal stage of HIV-AIDS.

Ivory Harvesting Pressure on the Genome of the African Elephant: A Phenotypic Shift to Tusklessness.

The unique chequered pattern of elephant ivory has made it a desired commodity for the production of various works of art. The demand however outstrips the supply and with soaring prices, illegal tusk harvesting is thriving on the African continent. Formal restrictions placed on trade in elephant products have been ineffective in reversing the rapid decline in elephant numbers. We are presently facing the reality of extinction of free roaming elephant on the African continent. This paper describes the histogenesis of the chequered pattern, the genomic impact of ivory harvesting on the phenotype of breeding herds, and the contribution of science to tracing the origin of illegal ivory.

Osseous Dysplasia with Gross Jaw Expansion: A Review of 18 Lesions.

Fourteen cases with 18 grossly expansive lesions diagnosed over a period of 15 years as either "familial gigantiform cementoma" or "osseous dysplasia with jaw expansion" in an African population sample were reviewed. Eight lesions occurred in the anterior mandible, the maxilla was affected by four, three patients presented with more than one lesion and the most common associated pathologies were tooth displacement, conventional non expanding florid osseous dysplasia and simple bone cyst. No history of similar lesions in relatives of the diseased were recorded. The radiolucent fibrous component contained globular bone deposits and cellular osteoid with trabecular differentiation which matured into radiodense mineralized masses. Resorption of the cellular bone created cavities which are proposed to represent the early stage of simple bone cyst formation. It is recommended that "expansive osseous dysplasia" replace the out-dated term "familial gigantiform cementoma". The differential diagnoses of expansive osseous dysplasias are discussed.

HIV/TB co-infection: literature review and report of multiple tuberculosis oral ulcers.

Human immunodeficiency virus/tuberculosis (HIV/TB) co-infected subjects demonstrate enhanced HIV replication and plasma viremia; CD4+ T-cell depletion; morbidity and mortality; and susceptibility to secondary bacterial and fungal infections compared to subjects solely infected with HIV. As the incidence of HIV/TB infection has been increasing, one would have expected to encounter oral lesions of tuberculosis more frequently. However, such oral lesions are uncommon. The lesions usually occur as ulcerations of the tongue. We report an additional case in an HIV/TB co-infected 39 year-old black male, who presented with chronic, painless, multiple oral ulcers, occurring simultaneously on the tongue, bilaterally on the palate and mucosa of the alveolar ridge. Microscopic examination confirmed the presence of chronic necrotizing granulomatous inflammation, with the identification of acid fast bacilli in the affected oral mucosal tissue. Anti-retroviral and anti-tuberculous treatment resulted in the resolution of the oral lesions. Confirmatory histopathological diagnosis following a biopsy is essential to determine the exact nature of chronic oral ulceration in an HIV individual and especially to distinguish between oral squamous cell carcimoma, lymphoma, infection (bacterial or fungal) and non-specific or aphthous type ulceration.

Expansive jaw lesions in chronic kidney disease: review of the literature and a report of two cases.

Chronic kidney disease is an increasing public health problem, with a worldwide prevalence estimated to be between 8% and 16%. The metabolic alterations induce bone and soft tissue changes, and the encompassing term chronic kidney disease-mineral and bone disorder syndrome (CKD-MBD) is used to describe them. The cardinal manifestations of the syndrome are bone catabolism and soft tissue calcifications, which ultimately compromise the cardiovascular and skeletal systems. In rare cases, tumorous enlargement of the craniofacial bones occurs. This article provides a brief review of the pathogenesis and imaging of craniofacial changes in CKD-MBD and reports on two cases of expansive jaw lesions. The term expansive renal osteitis fibrosa is recommended to describe these lesions.

Central odontogenic fibroma-like tumors, hypodontia, and enamel dysplasia: review of the literature and report of a case.

A patient with multiple odontogenic fibroma-like tumors in the mandible and enamel dysplasia is presented, bringing the total number of cases reported in the literature to 3. In addition to these manifestations, this case had hypodontia. The absence of associated teeth, the size of the lesions, the lingual expansion, and the green-yellow polarization of collagen with Picrosirius stains supported the neoplastic nature of the central odontogenic fibroma-like tumors in the case presented. Laminated psammomatous deposits distinguished the tumors from the World Health Organization-type central odontogenic fibroma.

Cemento-ossifying fibroma: case report and review of the literature.

Although the neoplastic nature of intrabony cemento-ossifying fibromas is beyond dispute, controversy exists regarding the soft tissue counterpart. Peripheral cemento-ossifying fibroma has been referred to by a variety of terms depending on whether it is accepted as being a true odontogenic tumor or a reactive gingival overgrowth. The management of a patient with peripheral cemento-ossifying fibroma in the masticatory mucosa of the anterior region of the maxilla is presented. The differential diagnosis of reactive gingival overgrowths with and without calcification is discussed.

Second malignancies in Hodgkin's disease: A review of the literature and report of a case with a secondary Lennert's lymphoma.

A small percentage of patients treated for Hodgkin's disease are at risk of developing a second malignancy. The appearance of secondary malignancies such as leukemia, carcinoma or non-Hodgkin's lymphomas may be attributed to the mutagenic effects of chemotherapy and/or radiotherapy. Most secondary non-Hodgkin's lymphomas are of the B-cell type, but isolated cases were reportedly of a T-cell lineage. A review of the literature pertaining to the development of secondary peripheral T-cell lymphomas is presented along with the description of an additional case. The latter developed in the tonsil and was diagnosed as a Lennert's lymphoma (lymphoepithelioid T cell lymphoma)on histological and immunological grounds. This report also reviews the development of a of peripheral T-cell lymphoma described in patients following chemotherapy and/or radiotherapy for Hodgkin's disease.

Recent developments in metabolic bone diseases: a gnathic perspective.

Metabolic bone diseases often are asymptomatic and progress sub clinically. Many patients present at a late stage with catastrophic skeletal and extra skeletal complications. In this article, we provide an overview of normal bone remodeling and a synopsis of recent developments in the following conditions: osteoporosis, rickets/osteomalacia, endocrine-induced bone disease, chronic kidney disease-mineral bone disorder and Paget's disease of bone. Our discussion will emphasize the clinical and microscopic manifestations of these diseases in the jaws.