SATB2 is not a reliable diagnostic marker for distinguishing between oral osteosarcoma and fibro-osseous lesions of the jaws

Osteoblastoma of the Mandible: A Case Report

Osteoblastoma is a rare, benign bone tumor primarily affecting the spine but can occasionally involve the jaws, particularly the mandible. This report discusses the case of a 38-year-old female patient presenting with mild pain and swelling in the left mandibular region for the past few months. Clinical, radiographic, and histopathological evaluation confirmed the diagnosis of osteoblastoma. A conservative surgical excision was performed. No recurrence was observed on follow-up. Differential diagnoses included low-grade osteosarcoma, osteoid osteoma, and other bone-forming lesions. This case report emphasizes the importance of distinguishing osteoblastoma from similar lesions to ensure appropriate treatment and favorable prognosis.

Cemento-ossifying fibroma transforming to osteosarcoma

Ossifying fibroma is a type of fibro-osseous lesion categorised into cemento-ossifying fibroma and juvenile ossifying fibroma. Malignant transformation of fibro-osseous lesions is documented especially for fibrous dysplasia, but scarcity is seen when we search for malignant transformation of ossifying fibroma. Thus, we are presenting an extremely rare case of cemento-ossifying fibroma transforming into osteosarcoma with long sequential radiographic details.

Special AT-rich sequence-binding protein 2 (SATB2) in the differential diagnosis of osteogenic and non-osteogenic bone and soft tissue tumors

Background

The diagnosis of osteosarcoma (OSA) depends on clinicopathological and radiological correlation. A biopsy is considered the gold standard for OSA diagnosis. However, since OSA is a great histological mimicker, diagnostic challenges exist. Immunohistochemistry (IHC) can serve as an adjunct for the histological diagnosis of OSA. Special AT-rich sequence-binding protein 2 (SATB2) was recently described as a reliable adjunct immunohistochemical marker for the diagnosis of OSA.

Methods

We investigated the IHC expression of SATB2 in 95 OSA and 100 non-osteogenic bone and soft tissue tumors using a monoclonal antibody (clone EPNCIR30A). The diagnostic utility of SATB2 and correlation with clinicopathological parameters were analyzed.

Results

SATB2 IHC was positive in 88 out of 95 cases (92.6%) of OSA and 50 out of 100 cases (50.0%) of primary non-osteogenic bone and soft tissue tumors. Of the 59 bone tumors, 37 cases (62.7%) were positive for SATB2, and of the 41 soft tissue tumors, 13 cases (31.7%) were positive for SATB2. The sensitivity of SATB2 as a diagnostic test was 92.6%, specificity 50%, positive predictive value 63.8%, and negative predictive value 87.7%.

Conclusions

Although SATB2 is a useful diagnostic marker for OSA, other clinical, histological and immunohistochemical features should be considered for the interpretation of SATB2.

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.

Ossifying Fibromas of the Head and Neck Region: A Clinicopathological Study of 45 Cases

Ossifying fibromas of the head and neck region are classified as cemento-ossifying fibroma (COF) (odontogenic origin), and two types of juvenile ossifying fibromas: juvenile trabecular ossifying fibroma (JTOF), and juvenile psammomatous ossifying fibroma (JPOF). The potential for recurrence in JTOF and JPOF and the discovery of newer molecular signatures necessitates accurate histological classification. Over 12 years (2005-2017), a total of 45 patients with 51 tumours were retrieved and reviewed for clinic-pathological features from the archives of a tertiary care oncology centre. Of 45 cases, COF, JTOF and JPOF comprised 13 (28.9%), 11 (24.4%) and 18 (40%) cases respectively. Three cases were unclassifiable. M: F ratio was 1:3.3, 1.1:1, 2:1 for COF, JTOF and JPOF respectively with an age range of 6-66 years (mean: 24.6, median; 18.1 years). The most common site for COF was mandible, for JTOF was maxilla, and for JPOF was ethmoid sinus. One case of mixed JTOF and JPOF histology was seen. Aneurysmal bone cyst-like areas were seen in 26.6% of cases, most commonly in JPOF. Follow up was available in 23 cases, and ranged from 4 to 207 months. Three cases of JPOF had a recurrence and one patient with JTOF had residual disease after surgery. One case of COF demonstrated increased parathyroid hormone levels. COF, JTOF, and JPOF are clinically, radiologically and histologically distinct entities. Surgical resection is the mainstay of treatment. JPOF has a higher incidence of recurrence as compared to JTOF and COF and hence needs a more aggressive follow-up.