Extraskeletal osteosarcoma arising in an ectopic hamartomatous thymus. Report of a case and review of the literature

Fibrosarcoma of the Thymic Region. A Case Report

Fibrosarcoma of the mediastinum is an unusual tumor and only few cases have been reported. We describe the clinical and pathologic findings of a case of mediastinal mass in a 34 year old woman. The histologic, histochemical, immunocytochemical and ultrastructural features of the tumor were consistent with a diagnosis of fibrosarcoma. Furthermore, the tumor displayed evidence of close relations with the thymus capsule; the possibility that it may arise from the thymic stroma is considered. The differential diagnosis of spindle cell tumors of the mediastinum is also discussed.

Extraskeletal osteosarcoma arising in myositis ossificans: a case report and review of the literature

We report a case of a 23-year-old female with pain and fullness in the right popliteal fossa. An MRI scan demonstrated an ossified enhancing soft tissue mass. Evaluation of the resected specimen showed a high-grade extraskeletal osteosarcoma juxtaposed to the three zones of myositis ossificans. At 1-year follow-up the patient is alive and disease free. A review of the literature purporting to document such an association failed to demonstrate a single case in which an osteosarcoma and MO with its zonal architecture co-existed.

Cutaneous metastasis of extraskeletal osteosarcoma arising in the mediastinum

Cutaneous metastases have been reported in 5%-10% of patients with internal malignancy. The most common clinical features are the sudden appearance of discrete, firm, and nontender nodules in a particular area of the body. The most frequent metastatic site of extraskeletal osteosarcoma (ESOS) is the lungs. Cutaneous metastasis of ESOS is rare. To our knowledge, only one case of ESOS has been reported with skin metastasis, histopathologically classified as the osteoblastic subtype. Here, we describe a case of chondroblastic ESOS arising in the mediastinum with metastasis to the skin. Our patient presented with a scalp nodule after diagnosis of primary ESOS at the mediastinum.

A chemosensitive pediatric extraosseous osteosarcoma: case report and review of the literature

Osteosarcoma arising in soft tissues is exceedingly rare in children. The tumor most often affects older adults, involves the lower extremity, responds poorly to chemotherapy, and carries a grave prognosis. The authors describe a 12-year-old girl with an extraosseous osteosarcoma of the left sternocleidomastoid muscle with pulmonary metastases. The patient responded well to neoadjuvant chemotherapy and remains disease-free nearly 3 years after her initial diagnosis. The authors review available information about this disease in children and adults. Children with extraosseous osteosarcoma may have a more favorable response to treatment than adults; thus, a curative approach using combined modality therapy appears warranted.

Primary osteosarcoma arising in the colon: report of a case

A 53-year-old female presented with abdominal pain, and computed tomography scan revealed a small, calcified lesion in the wall of the transverse colon. The symptoms later disappeared spontaneously, and she remained in good health. However, four years later, she developed lancinating abdominal pain and was admitted to our hospital. A large tumor with calcification was found in the left upper abdominal cavity. Curative resection of the tumor was performed, and the histology was compatible with extraskeletal osteosarcoma. We speculated that the tumor originated from the colonic wall, because a small calcification was observed in the wall of the transverse colon four years before surgery. To the best of our knowledge, this is the first report of primary colonic osteosarcoma.

Extraosseous osteogenic sarcoma--a rare pediatric malignancy: case report and review of the literature

BACKGROUND

Osteogenic sarcoma rarely occurs in soft tissues and generally affects individuals beyond the second decade of life.

METHODS

The authors report a rare case of an extra osseous osteogenic sarcoma arising in the retroperitoneum of an adolescent, review the literature, and outline the diagnostic and therapeutic dilemmas. The role of adjuvant chemotherapy, using drugs used in managing bony osteosarcomas, is discussed.

CONCLUSIONS

Retroperitoneal sarcomas may simulate ovarian teratomas. Careful consideration of the differential diagnosis of large cystic abdominal masses in adolescent females when size precludes adequate assessment of tumor mobility and imaging fails to demonstrate the ovaries is essential if these rare tumors are to be managed effectively.

Ectopic cervical hamartomatous thymoma showing extensive myoid differentiation

Ectopic 'hamartomatous' thymoma is a rare benign neoplasm. These tumours are found in the neck and are thought to be part of a spectrum of ectopic cervical thymic neoplasia. The clinical and histological features are discussed and the literature is reviewed. An attempt is made to explain in embryological terms why such lesions appear to occur more commonly on the left side.

Primary osteogenic sarcoma of the posterior mediastinum. Case report

Extraosseous osteogenic sarcoma of the mediastinum is an extremely rare tumour, usually arising in the anterosuperior compartment. Clinical findings in the first reported case of high-grade osteogenic sarcoma arising in the posterior mediastinum are described.

Extraskeletal osteosarcoma with unusual ultrastructural features

A case of extraskeletal osteosarcoma was observed in the thigh of a 33-year-old male patient. Ultrastructurally the tumor was characterized by the presence of a particular dense type of cell, the nucleus of which showed a characteristic combination of features: large amounts of condensed marginated chromatin, prominent perichromatin granules, vermicellar bodies, and undulating microtubules. The tumor also contained intermediate-type cells with a more typical osteoblastic appearance, and more blastic cells. All three cell types contained varying amounts of dilated rough endoplasmic reticulum with prominent inclusions of crystalline material showing a hexagonal or banded pattern, indicating that the cells represent different stages of maturation rather than genuinely different types of cells. Dense cells showing the same characteristic combination of nuclear features have been described once before in a case of parosteal osteosarcoma. Our results indicate that these cells are a particular form of osteogenic cell. The presence of undulating microtubules and vermicellar bodies suggest a possible association with the presence of virus and/or increased levels of interferon.

Extraskeletal osteosarcoma. A clinicopathologic review of 26 cases

The clinical records and histopathologic features in 26 cases of extraskeletal osteosarcoma (ESOS) diagnosed at M.D. Anderson Cancer Center (Houston) between 1950 and 1987 were reviewed. Presentation was usually that of an enlarging soft tissue mass. The thigh (11 cases), upper extremity/shoulder girdle (three cases), and retroperitoneum (three cases) were the most common anatomic sites. Tumor size ranged from 2.5 to 30 cm. The predominant histologic pattern was osteoblastic in four cases, chondroblastic in two, fibroblastic or pleomorphic malignant fibrous histiocytoma (MFH)-like in four, giant cell type MFH-like in one, and small cell in one. Various mixtures of these patterns were seen in the remaining 14 tumors. The telangiectatic pattern was not seen as the predominant component in any primary tumor but was observed as a minor component. Thirteen tumors recurred locally and 16 metastasized; five patients had distant metastases at presentation. The lungs, bone, and soft tissue were the most frequent metastatic sites. Sixteen patients died of disease at 2 to 54 months, one patient died of unrelated causes at 61 months, seven patients were alive with no evidence of disease (NED) at 30 to 122 months, and two patients were alive with disease at 28 and 54 months, respectively. Tumor size (less than 5 cm versus greater than or equal to 5 cm) was the main prognostic factor; all patients alive with NED for whom accurate tumor measurements were available (six of seven) had neoplasms measuring less than 5 cm that were amenable to complete surgical excision. Histologic pattern and other clinicopathologic features did not significantly affect outcome.

Canine extraskeletal osteosarcoma and chondrosarcoma: a clinicopathologic study of 14 cases

Canine extraskeletal osteosarcomas are extremely rare tumors. Over a period of 25 years at the Animal Medical Center, approximately 1,000 cases of skeletal osteosarcomas have been diagnosed. During the same period 11 cases of extraskeletal osteosarcomas and three extraskeletal chondrosarcomas were diagnosed. Tumors of the mammary gland were excluded. Extraskeletal osteosarcomas were found in the adrenal gland, eye, gastric ligament, ileum, kidney, liver, spleen, testicle, and vagina. The chondrosarcomas were found in the mitral valves, lungs, and omentum. The mean age of the dogs with extraskeletal osteosarcoma was 11 years, and the mean age of the dogs with extraskeletal chondrosarcoma was 14 years. The The sizes of the tumors ranged from 3 cubic centimeters to 8,315 cubic centimeters. Osteoblastic osteosarcomas were the most common histologic type (7/11, 63.6%); there was a single case of each of the following: fibroblastic, fibrous histiocytic, chondroblastic, and mixed osteo-chondroblastic osteosarcoma. Two of the dogs with chondrosarcomas had mesenchymal chondrosarcomas involving the lungs and omentum. The remaining dog had a regular chondrosarcoma involving the mitral valve. Distant metastases were present in seven of 11 dogs with extraskeletal osteosarcoma and in none of the dogs with chondrosarcoma. In contrast to human beings, in which most extraskeletal osteosarcomas occur in the soft tissues and the extremities, most canine extraskeletal osteosarcomas develop in the visceral organs.

Osteosarcoma

Osteosarcoma is the most common bone tumor of children and adolescents. The peak incidence of the disease is in the 15 to 19 year age group. The disease is more commonly seen in males than females. While several factors, including exposure to radiation, genetic disorders such as retinoblastoma, and high rate of bone growth, have been associated with osteosarcoma, in most cases no definite etiology can be established. Osteosarcoma usually originates in the metaphyseal region of long bones and extends through the cortex, causing varying degrees of bone destruction and expansion of periosteum. The radiographic appearance caused by this process is often referred to as "sun burst" sign. Positive diagnosis of osteosarcoma is made by histopathology. The histopathological classification of osteosarcoma can also predict the degree of aggressive behavior of this tumor and thus has prognostic significance. Surgery, including amputation or limb-salvage procedure, is the mainstay of treatment of osteosarcoma. It is now unequivocally established that adjuvant chemotherapy will prolong the survival of patients with this disease. Chemotherapy agents often used include platinum derivates, methotrexate, vincristine, cyclophosphamide, adriamycin, actinomycin D, bleomycin and DTIC. Depending on surgical decision, these agents can be used prior to or after the operation. Immediate fitting with prosthesis and provision of appropriate medical and psychological support in the care of these patients is essential.

Association of inflammatory bowel disease (IBD) with indolent soft-tissue sarcomas: report of two cases and review of literature

Two patients with inflammatory bowel disease (IBD) and indolent forms of soft-tissue sarcomas (extraosseous osteogenic sarcoma and desmoid tumor) are presented. The literature is reviewed regarding these tumors, which have not previously been recognized in association with IBD. Despite the well-established relationship between IBD and neoplasms of epithelial and lymphoreticular origin, there have been limited data in this context pertaining to mesenchymal tumors. Two preceding reports have described the coexistence of IBD with another form of soft tissue sarcoma (Kaposi's sarcoma). Given that this relationship has now been observed in four cases, the possibility that soft-tissue sarcoma and IBD do not coexist fortuitously must be considered. This suggestion is raised in light of the rare incidence of these disorders, the limited understanding of factors governing their expression, and the known association of IBD with other forms of neoplasia.

Extraosseous osteogenic sarcoma arising from the retroperitoneum: a case report

A 44-year-old housewife with a mass in the left upper quadrant of the abdomen was admitted. The tentative diagnosis was cystadenocarcinoma arising from the pancreatic tail, as determined by CT and selective angiography. Excision of the mass with removal of the spleen, pancreatic tail, left renal capsule and surrounding lymphnodes was performed. Photomicroscopic sections revealed proliferation of malignant cells and malignant osteoids. The final diagnosis was osteogenic sarcoma arising from the retroperitoneum. Among the extraosseous osteogenic sarcoma arising from the somatic soft tissue, involvement of the retroperitoneum is rare. Only 12 cases including our own case have been reported as being of retroperitoneal origin. No patient survived for five years and in our patient, there are signs of recurrence one year after the surgery.