HMGA2 Immunoexpression is frequent in salivary gland pleomorphic adenoma: immunohistochemical and molecular analyses of PLAG1 and HMGA2 in 25 cases.

The main oncologic events in pleomorphic adenoma (PA) are the translocations of Pleomorphic adenoma gene 1 (PLAG1) on chromosome 8q12 and High-mobility group AT-hook 2 (HMGA2) on chromosome 12q14.3 with various fusion partners. These translocations result in the transcriptional up-regulation of PLAG1 and HMGA2 proteins. We carried out a preliminary evaluation of PLAG1 translocation by fluorescence in-situ hybridization (FISH), immunohistochemistry (IHC) and HMGA2 IHC on twenty-five archived formalin-fixed paraffin-embedded tissues of PAs and its clinicopathologic features. Only eight cases were successfully hybridized and 50% of the interpretable cases were considered positive for PLAG1 translocation. PLAG1 IHC was only positive in 2 (8%) of the 25 cases stained, including one of the positive PLAG1 translocation cases. HMGA2 IHC was positive in 12 (48%) of the 25 cases stained including 2 (50%) of the 4 cases identified with PLAG1 translocation by FISH, 3 (75%) of the 4 cases negative for PLAG1 translocation by FISH and 7 (41%) of the 17 cases with failed hybridization. Overall, 15 (60%) of the 25 PA cases demonstrated PLAG1 and/or HMGA2 alterations confirmed either by FISH or IHC. In conclusion, PLAG1 and HMGA2 alterations were confirmed either by FISH or IHC in this cohort and HMGA2 alteration is a common event in PAs of salivary gland.

SATB2 and MDM2 Immunoexpression and Diagnostic Role in Primary Osteosarcomas of the Jaw.

Primary osteosarcomas of the jaw (OSJ) are rare, accounting for 6% of all osteosarcomas. This study aims to determine the value of SATB2 and MDM2 immunohistochemistry (IHC) in differentiating OSJ from other jawbone mimickers, such as benign fibro-osseous lesions (BFOLs) of the jaw or Ewing sarcoma of the jaw. Certain subsets of osteosarcoma harbor a supernumerary ring and/or giant marker chromosomes with amplification of the 12q13-15 region, including the murine double-minute type 2 (MDM2) and cyclin-dependent kinase 4 (CDK4) genes. Special AT-rich sequence-binding protein 2 (SATB2) is an immunophenotypic marker for osteoblastic differentiation. Cases of OSJ, BFOLs (ossifying fibroma and fibrous dysplasia) of the jaw, and Ewing sarcoma of the jaw were retrieved from the Departments of Oral Pathology and Oral Medicine, Faculty of Dentistry, Obafemi Awolowo University and Lagos State University College of Medicine, Nigeria. All OSJ retrieved showed histologic features of high-grade osteosarcoma. IHC for SATB2 (clone EP281) and MDM2 (clone IF2), as well as fluorescence in situ hybridization (FISH) for MDM2 amplification, were performed on all cases. SATB2 was expressed in a strong intensity and diffuse staining pattern in all cases (11 OSJ, including a small-cell variant, 7 ossifying fibromas, and 5 fibrous dysplasias) except in Ewing sarcoma, where it was negative in neoplastic cells. MDM2 was expressed in a weak to moderate intensity and scattered focal to limited diffuse staining pattern in 27% (3/11) of cases of OSJ and negative in all BFOLs and the Ewing sarcoma. MDM2 amplification was negative by FISH in interpretable cases. In conclusion, the three cases of high-grade OSJs that expressed MDM2 may have undergone transformation from a low-grade osteosarcoma (LGOS). SATB2 is not a dependable diagnostic marker to differentiate OSJ from BFOLs of the jaw; however, it could serve as a valuable diagnostic marker in differentiating the small-cell variant of OSJ from Ewing sarcoma of the jaw, while MDM2 may be a useful diagnostic marker in differentiating OSJ from BFOLs of the jaw, especially in the case of an LGOS or high-grade transformed osteosarcoma.

MYB-NFIB Translocation by FISH in Adenoid Cystic Carcinoma of the Head and Neck in Nigerian Patients: A Preliminary Report.

Adenoid cystic carcinoma (AdCC) is a relatively rare malignancy of head and neck sites such as the salivary glands, lacrimal gland, sinonasal region, and pharynx and may arise in other exocrine glands. The oncologic event in AdCC is the translocation between MYB proto-oncogene transcription factor (MYB) and nuclear factor I/B (NFIB) resulting in t(6;9)(q22-23;p23-24). We carried out a preliminary evaluation of MYB-NFIB translocation by fluorescence in-situ hybridization on seven archived formalin-fixed paraffin-embedded tissues of AdCC of Nigerian patients and its clinicopathologic features. Only 3 of the 7 cases were successfully hybridized, all featuring MYB-NFIB translocations with a range of 14.7-83.3% of translocated cells in 60 cells examined. The 3 translocation positive cases were located in the maxillary sinus, buccal mucosa and parotid. Their morphologic appearances were cribriform-solid (1) & cribriform (2) and classified as grades III (1) & I (2), respectively. These patients may potentially benefit from MYB-targeted anti-neoplastic therapy.

Pattern of distribution of reactive localised hyperplasia of the oral cavity in patients at a tertiary health institution in Nigeria.

BACKGROUND: Reactive localized hyperplastic lesions of the oral cavity (RHLs) are relatively common peripheral lesions which present as a range of clinically similar lesions at dental centers. Diagnosis can be challenging if dentists are unfamiliar with their clinicopathological across various populations. OBJECTIVE: This study reviews the pattern of distribution of RHLs of the oral mucosa in a hospital- the Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Ile-Ife. MATERIALS AND METHODS: We reviewed 10 years data from the archives of the Department of Oral Maxillofacial Surgery and Oral Pathology, Obafemi Awolowo University, Nigeria. Information on RHLs were extracted and recorded on standardized data forms and analyzed using STATA. RESULTS: The most common lesions were pyogenic granuloma (43.7%) and focal fibrous hyperplasia (39.7%), respectively. RHLs were found to be more frequent in women (66.7%) than men (33.3%). The most common locations of involvement was the gingivae (84.6%), and lesions were more common in the 9-29 year age group and the mean age was 37.7 (±21.1) years. The relationship between age group and reactive lesions was however not statistically significant. CONCLUSION: The major benefit of this study is an improved knowledge of the frequency and distribution of oral reactive lesions in sub-Saharan Africa which may be highly beneficial when establishing a diagnosis and treatment plan in clinical practice.

Salivary Flow Rates of Nigerian Patients with Chronic Kidney Disease: A Case-control Study.

AIMS AND OBJECTIVES: The study determined the relationship between chronic kidney disease (CKD) and changes in salivary flow and the complications of reduced salivary flow among African subjects with CKD compared with the controls. MATERIALS AND METHODS: One hundred and eighty patients, 90 C KD and 90 controls were recruited, interviewed and examined. Stimulated and unstimulated saliva collection was done with standardized spitting method. Urinalysis and blood creatinine levels were determined and glomerular filtration rate (GFR) of each patient was calculated from the blood creatinine using Cockcroft and Gault formula. Statistical analysis was done using STATA 11 software. RESULTS: The mean stimulated and unstimulated whole salivary flow rate among CKD subjects were 4.07 ± 1.91 and 2.34 ± 0.99 ml/5 min respectively and is significantly lower than that of the controls which were 8.05 ± 3.95 ml/5 min and 3.82 ± 2.27 ml/5 min for stimulated and unstimulated flow rates. Oral signs of reduced salivary flow were found in 80% of CKD patients. The commonest oral finding was taste abnormalities others are burning sensation, halitosis and difficulty in mastication. CONCLUSION: Patients with CKD had reduced stimulated and unstimulated salivary flow rate. Reduced salivary flow was associated with oral lesions in majority (80%) of CKD patients, the commonest finding being taste abnormalities.