Epithelioid osteosarcoma of the maxilla: report of an unusual case

Rosette-forming epithelioid osteosarcoma in the rib: a rare case of location and morphology

The rib is an unusual location for osteosarcoma and is reported in only 2% of all cases. The major histological variants of osteosarcoma are osteoblastic, chondroblastic, and fibroblastic, with a few rare variants including one epithelioid type. This report describes a 44-year-old male with an osteolytic mass in the right seventh rib. Histological examination revealed osteosarcoma with unique features of epithelioid appearance and rosette structures. To the best of our knowledge, this is the first reported case of a rosette-forming osteosarcoma of the rib that showed epithelioid morphology. Despite successful surgery, the patient’s prognosis was poor because this malignancy had an unusual location within the axial skeleton and was a rare histological variant.

Osteosarcoma of the jaw: report of 3 cases (including the rare epithelioid variant) with review of literature

Osteosarcoma of the jaw (OSJ) is a rare malignancy, accounting for less than 1% of head and neck malignancies. OSJ can arise as a primary malignancy or secondary to locoregional radiation treatment. Radiologically, these tumors show large, destructive growth with periosteal reaction, which can suggest the diagnosis of osteosarcoma (OS). However, histology with demonstration of neoplastic, "lacelike" osteoid is the key to determining the diagnosis. Small tissue samples can complicate the diagnosis, especially in cases of high-grade OS with sheetlike growth and scant areas of immature osteoid formation. We report 3 cases of OSJ, including 1 rare case of epithelioid OS of the mandible, diagnosed at our hospital over a 6-month period: case 1: a 48-year-old male with history of Hodgkin lymphoma, who was treated with radiation and developed osteoblastic OS of the mandible 14 years later; case 2: a 79-year-old female with a history of fibrous dysplasia, who presented with a large destructive maxillary mass, which was diagnosed as histologically fibroblastic OSJ of the maxilla; and case 3: a 70-year-old male with radiation-induced high-grade epithelioid OS, which had been incorrectly diagnosed as poorly differentiated squamous cell carcinoma on a small biopsy specimen; this patient experienced recurrence with multiple neck nodules after treatment, underwent repeat resection, and was finally diagnosed with high-grade OS (epithelioid type).

Metachronous extraskeletal (soft tissue) epithelioid osteogenic sarcoma: a case report

Background

Metachronous osteosarcoma is a rare form of osteosarcoma. The occurrence of metachronous tumor in soft tissue is exceedingly rare. The pathogenesis of metachronous osteosarcoma, as to whether it represents multiple true primaries or metastatic disease, is still obscure.

Case presentation

A 49-year-old Indian man presented with progressively increasing swelling in his left hand of 2 months’ duration. An X-ray showed a soft tissue lesion. Contrast-enhanced computed tomography showed a soft tissue mass lesion, with peripheral enhancement and central necrotic areas in radial palmar soft tissue overlying second metacarpophalangeal region with no obvious bony osteolysis. Possibilities of acute abscess, resolving hematoma, or aggressive soft tissue mass lesion were suggested. An incision biopsy showed morphological features of epithelioid osteosarcoma, which was confirmed on immunohistochemistry. A detailed history revealed that our patient was diagnosed as having osteosarcoma of his right leg 3 years previously. Based on history, radiology, morphology, and immunohistochemistry, a final diagnosis of extraskeletal (soft tissue) epithelioid osteogenic sarcoma of the left hand occurring as a metachronous tumor 3 years after diagnosis of primary osteosarcoma in the right leg was given.

Conclusion

This is probably the first reported case of extraskeletal (soft tissue) epithelioid osteosarcoma occurring as a metachronous tumor 3 years after diagnosis of primary osteosarcoma in the right leg. The prognosis of metachronous skeletal osteosarcoma is poor as compared to that of relapse limited to lungs. In late metachronous osteosarcoma, combined-modality therapy comprising surgery and aggressive chemotherapy may affect long-term survival. Lifelong follow-up of surviving patients with osteosarcoma is necessary and if metachronous osteosarcoma is discovered, it should be treated with curative intent.

Electronic supplementary material

The online version of this article (10.1186/s13256-019-2070-3) contains supplementary material, which is available to authorized users.

Epithelioid Osteosarcoma of the Maxilla

Epithelioid osteosarcoma is an uncommon variant; only 4 cases have been reported in the jaw area, 2 of which were in the maxilla. A 22-year-old woman, in the eighth month of pregnancy, presented to the oral surgery clinic with a mass in the right maxilla that had rapidly expanded over the past 3 months. Computed tomography scans showed an ill-defined sclerotic destructive lesion that formed bone matrix in its soft tissue extension. Microscopic examination of the lesion revealed malignant epithelioid cells with osteoid deposits. The tumor cells were shown to have pale cytoplasm, vesicular nuclei, and prominent nucleoli and to undergo frequent mitosis. In addition, the tumor was positive for epithelial membrane antigen and vimentin and negative for AE1/AE3, Melan-A, CD30, synaptophysin, NSE, CD45, CD99, desmin, and myogenin. The final diagnosis was epithelioid osteosarcoma, which is a rare aggressive variant of osteosarcoma. Few cases of epithelioid osteosarcoma have been reported in the literature, and more studies are required to determine the clinical behavior of this tumor.

Diversity of Histologic Patterns and Expression of Cytoskeletal Proteins in Canine Skeletal Osteosarcoma

Osteosarcoma (OS), the most common bone tumor, includes OS of the head (OSH) and appendicular OS (OSA). In dogs, it is classified into 6 histologic subtypes: osteoblastic, chondroblastic, fibroblastic, telangiectatic, giant cell, and poorly differentiated. This study investigated the significance of the histologic classification relevant to clinical outcome and the histologic and immunohistochemical relationships between pleomorphism and expression of cytoskeletal proteins in 60 cases each of OSH and OSA. Most neoplasms exhibited histologic diversity, and 64% of OS contained multiple subtypes. In addition to the above 6 subtypes, myxoid, round cell, and epithelioid subtypes were observed. Although the epithelioid subtypes were observed in only OSH, no significant difference in the frequency of other subtypes was observed. Also, no significant relevance was observed between the clinical outcome and histologic subtypes. Cytokeratin (CK) was expressed in both epithelioid and sarcomatoid tumor cells in various subtypes, and all CK-positive tumor cells also expressed vimentin. Vimentin and α-smooth muscle actin (SMA) were expressed in all subtypes. A few SMA-positive spindle-shaped tumor cells exhibited desmin expression. Glial fibrillary acidic protein-positive tumor cells were observed in many subtypes, and some of these cells showed neurofilament expression. Although OSH exhibited significantly stronger immunoreactivity for SMA than OSA, no significant difference in other cytoskeletal proteins was observed. Some tumor cells had cytoskeletal protein expression compatible with the corresponding histologic subtypes, such as CK in the epithelioid subtype and SMA in the fibroblastic subtype. Thus, canine skeletal OS is composed of pleomorphic and heterogenous tumor cells as is reflected in the diversity of histologic patterns and expression of cytoskeletal proteins.

Osteosarcoma of the maxilla: a rare case with unusual clinical presentation

Osteosarcoma (OS) is a malignant mesenchymal tumor, which rarely occurs in the maxilla. Although variable histologic and radiographic features of OS have been reported previously, in the majority of the cases painful swelling of the jaw is mentioned as the first clinical presentation. Furthermore, early diagnosis and wide surgical resection of the tumor are the most important determinant factors of prognosis. Therefore, the unusual clinical presentations of OS should be considered meticulously to expedite the diagnosis process. We describe a case of OS of the maxilla with extremely unusual presenta-tion in a 42-year-old female, that was initially designated as “epulis fissuratum”. Here, we highlight the importance of com-bining the clinical, radiographic and histopathologic examination to obtain a definitive diagnosis and also the significance ofearly effective surgical intervention in evaluation of pathologic lesions.

Osteosarcoma of the femur mimicking Ewing sarcoma/primitive neuroectodermal tumour on biopsy and metastatic carcinoma on resection

Osteosarcoma (OS) is known to have several morphological appearances, small cell osteosarcoma and epithelioid osteosarcoma being two well recognized patterns. The former can be mistaken for a Ewing sarcoma/primitive neuroectodermal tumour (ES/PNET), whereas the latter mimics metastatic carcinoma. Herein we present an osteosarcoma in a 17-year-old girl that was diagnosed as an ES/PNET on biopsy; however, the resected specimen revealed a very unusual morphology mimicking a metastatic carcinoma with a sex cord stromal tumour-like pattern.