Consistency of color-deconvolution for analysis of image intensity of alpha smooth muscle actin-positive myofibroblasts in solid multicystic ameloblastomas.

Ameloblastoma is an odontogenic tumor with a slow, locally aggressive growth pattern and multiple clinico-histologic types. The number of stromal myofibroblasts within ameloblastoma often is correlated with growth and aggressiveness. Color-deconvolution to separate different colors of immunostained tissues is a promising approach to quantifying myofibroblasts in tumors such as ameloblastoma. We investigated the reliability of the color-deconvolution method using cross-sectional design to evaluate alpha-smooth muscle actin (α-SMA)-positive myofibroblasts in solid multicystic ameloblastoma. Formalin fixed tissues of eight cases of solid multicystic ameloblastoma were immunostained for α-SMA using the horseradish peroxidase-diaminobenzidine (HRP-DAB) method. Color-deconvolution using ImageJ software was used to quantify the staining intensity of brown DAB α-SMA stained myofibroblasts. Color-deconvoluted images of brown DAB stained tissues exhibited distinct morphological features of solid multicystic ameloblastoma with α-SMA stained myofibroblasts distributed abundantly adjacent to the ameloblastoma epithelial islands. The computed image intensity of α-SMA stained myofibroblasts was quantitatively similar among the different ameloblastoma samples. A combination of color-deconvolution and α-SMA staining of myofibroblasts is a useful diagnostic tool for evaluating histologic differentiation and growth pattern of ameloblastoma.

Enhanced basal autophagy supports ameloblastoma-derived cell survival and reactivation.

OBJECTIVES: Ameloblastoma is an aggressive odontogenic jaw neoplasm. Its unlimited growth confers high potential for malignant transformation and recurrence. It is unclear why ameloblastoma is highly recurrent despite surgical resection with a wide margin of normal tissue. While canonical autophagy can be used to degrade and eliminate damaged cellular components, it is also a protective mechanism that provides energy and vital metabolites for cell survival. We used ameloblastoma-derived cells to test the hypothesis that autophagic processes play a role in survival and reactivation of ameloblastoma. METHODS: Primary epithelial (EP-AMCs) and mesenchymal (MS-AMCs) ameloblastoma-derived cells were established from tissue samples of solid multicystic ameloblastoma. Clonogenic capacity and basal autophagic capacity were assessed in ameloblastoma-derived cells relative to human odontoma-derived cells (HODCs) and maxilla-mesenchymal stem cells (MX-MSCs). Ability of ameloblastoma-derived cells to survive and form new ameloblastoma was assessed in mouse tumor xenografts. RESULTS: EP-AMCs were highly clonogenic (p < 0.0001) and demonstrated enhanced basal levels of autophagic proteins microtubule-associated protein 1-light chain 3 (LC3) (p < 0.01), p62 (Sequestosome 1, SQSTM1) (p < 0.01), and the LC3-adapter, melanoregulin (MREG) (p < 0.05) relative to controls. EP-AMCs xenografts regenerated solid ameloblastoma-like tumor with histological features of columnar ameloblast-like cells, loose stellate reticulum-like cells and regions of cystic degeneration characteristic of follicular variant of solid multicystic ameloblastoma. The xenografts also displayed stromal epithelial invaginations strongly reactive to LC3 and p62 suggestive of epithelial-mesenchymal transition and neoplastic odontogenic epithelium. CONCLUSIONS: EP-AMCs exhibit altered autophagic processes that can support survival and recurrence of post-surgical ameloblastoma cells.

Choriostoma of the gingivae following trauma: an unusual case in a Nigerian with review of relevant literature

Objective: Chondromas are benign intraosseous cartilaginous tumors composed of mature hyaline cartilage; they may however arise from the soft tissue in rare cases without bone or joint involvement and are called extra skeletal or soft tissue chondromas. Extra skeletal chondromas (ESC) are commonly seen in the hands and feet but rarely in the oral cavity. We report a rare case of extra skeletal chondroma of the gingiva in a 31-year-old male patient following trauma to the anterior maxillary soft and hard tissues.Case Description: This is a case of a 31year old hypertensive patient with 3weeks history of gingival swelling in relation to the upper incisors which were fractured following an injury sustained from a motorbike fall. Clinical examination revealed a firm, non-tender localized gingival enlargement adjacent to the palatal surfaces of the maxillary incisors which had a lobulated appearance, with areas of inflammation that bled on gentle probing. The palatal gingival swelling was excised under local anesthesia, while gingivoplasty was performed on the labial gingiva of the same teeth. A periodontal dressing was placed on the surgical sites and removed at one-week review. Histopathologic examination of the palatal swelling revealed connective tissue that was densely infiltrated by mixed inflammatory cells. In some areas, there was focal chondroid tissue with chondrocytes of varying sizes in a chondromyxoid matrix.Conclusion: A rare case of extra skeletal chondroma is reported, we encourage report of more cases with long term follow-up in multicenter study among Nigerians, to ascertain the prevalence, gender, site of ESC in this population

Pattern of distribution of odontogenic tumours in sub-Saharan Africa.

OBJECTIVE: To analyse documented reports on odontogenic tumours (OTs) in sub-Saharan Black Africa and to create awareness of the need for more reports on this topic. METHODS: There were 2,186 African cases of OTs presented at the International Association of Oral and Maxillofacial Pathologists (IAOP) Congress (Cape Town, South Africa) in 1998 that were added to 2,198 cases derived from reports published in the scientific literature from 1998 to date. The analysis undertaken included frequency distribution of available data on OTs that was listed in the 2005 World Health Organization (WHO) classification. The chi-square test was applied as appropriate. RESULTS: A total of 4,384 cases of OTs from only 14 of 47 sub-Saharan Black African countries were analysed. Ameloblastoma was the OT most commonly reported, accounting for 74.2% of OTs (and 86.9% of category A OTs), followed by keratocystic odontogenic tumour (KCOT) (6.9%) and odontogenic myxoma (ODM) (4.9%). Malignant OTs were reported at a low frequency, of 1.4%. Nigeria contributed 38.7% of the cases of OT in this series. CONCLUSIONS: Ameloblastoma is the commonest OT in sub-Saharan Africa and has a higher occurrence in male than in female subjects. With data on OTs not available from 33 of 47 sub-Saharan African countries, additional reports are needed.

Desmoplastic ameloblastoma: analysis of 17 Nigerian cases.

OBJECTIVE: This study aimed to add to existing knowledge on 90 cases of desmoplastic ameloblastoma (DA) previously reported in the scientific literature and analyze data that could help speculate on its biologic profile. STUDY DESIGN: From 330 cases of ameloblastoma (pooled from 573 histologically diagnosed odontogenic tumours) 17 cases of DA were retrieved and analyzed for estimated mean growth rate (EMGR) and histologic variants. EMGR for DA was compared with EMGR for conventional ameloblastoma (CA), as recorded over the same period of 38 years. RESULTS: Desmoplastic ameloblastoma had predilection for mandible (81.2%), posterior mandible being the most commonly affected, contrary to scientific literature reports of anterior maxillary predilection. Simple DA (88.0%) and DA with osteoplasia (12.0%) were the histologic variants observed. EMGR for DA (0.36 ± 0.44 cm/mo) was significantly less than EMGR (0.71 ± 1.16 cm/mo) for CA (P = .000480). CONCLUSION: This study speculates that DA tends to be less biologically aggressive than CA and has predilection for posterior mandible in Nigerians.

A clinicopathologic correlation in the diagnosis of periradicular lesions of extracted teeth.

PURPOSE: We aimed to determine the contributory percentage of histopathologic diagnoses of routine biopsies and to ascertain the possible indicators for histopathologic examination to confirm the clinical diagnosis of periradicular lesions of extracted teeth. PATIENTS AND METHODS: This was a prospective study carried out over a period of 8 months on patients who had single tooth extraction and routine histopathologic examination of recoverable periradicular tissues from extracted teeth. RESULTS: A total of 136 patients participated in this study. There was a male/female incidence ratio of 3:2 and most of the patients with histopathologically diagnosed lesions were within the first, second, and third decades of life (n = 49, 36.0%). Seventy-five (55.2%) cases had histopathologically diagnosed periradicular lesions, which were mostly periapical abscess (n = 30, 22.8%) and inflammatory (periapical) granuloma (n = 23, 16.9%). Some clinical and radiologic features were associated significantly with histopathologic diagnosis of some periradicular lesions (P < .05). There also was a significant correlation of clinical diagnosis with histopathologic diagnosis of inflammatory (periapical) granuloma, periapical abscess, chronic osteomyelitis, and Burkitt's lymphoma (P < .05). CONCLUSIONS: This study shows a higher contributory percentage of histopathologic diagnoses after routine biopsies, compared to previous reports from selected biopsies of periradicular lesions. We identified clinical indicators for predicting possible histopathologic diagnosis of some periradicular lesions, in particular, those that predict possible histologic diagnosis of neoplastic periradicular lesions.