Primary extraskeletal osteosarcoma of small bowel mesentery presenting with acute bowel obstruction

Extraskeletal osteosarcoma of the small bowel mesentery is an exceedingly rare condition. It is an aggressive malignant neoplasm of mesenchymal origin characterized by osteoid formation. Final diagnosis is often made by histopathological analysis. However, we believe that prospective radiological diagnosis may be possible through careful analysis of densities (ossification) within the mesenteric mass. To the best of our knowledge, there is no current literature describing the radiological approach to making a prospective diagnosis of this condition. We present the 12th case of extraskeletal osteosarcoma worldwide and describe a radiological approach that is potentially useful in making a prospective diagnosis.

Subcutaneous extraskeletal osteosarcoma of the foot: A case report

Extraskeletal osteosarcoma (ESOS) is a rare variant of osteosarcoma which occurs exclusively in the soft tissue without any bone involvement. Subcutaneous ESOS, in particular, is very rare and is seen in <10% of cases. Here, we report a case of a subcutaneous tumor in the fourth web space of the left foot in a 73-year-old man. The diagnosis of ESOS was made on histology and by immunohistochemical reactivity to special AT-rich sequence-binding protein 2 (SATB2), which is a sensitive, nuclear marker of osteoblastic differentiation. We present this case because of its rarity and the use of SATB2 immunohistochemistry to confirm the diagnosis.

Immunophenotyping of an Unusual Mixed-Type Extraskeletal Osteosarcoma in a Dog

A 6-year-old female Maltese dog presented with a cervical mass without pain. The tumor was surrounded by a thick fibrous tissue and consisted of an osteoid matrix with osteoblasts and two distinct areas: a mesenchymal cell-rich lesion with numerous multinucleated giant cells and a chondroid matrix-rich lesion. The tumor cells exhibited heterogeneous protein expression, including a positive expression of vimentin, cytokeratin, RANKL, CRLR, SOX9, and collagen 2, and was diagnosed as extraskeletal osteosarcoma. Despite its malignancy, the dog showed no sign of recurrence or metastasis three months after the resection. Further analysis of the tumor cells revealed a high expression of proliferation- and metastasis-related biomarkers in the absence of angiogenesis-related biomarkers, suggesting that the lack of angiogenesis and the elevated tumor-associated fibrosis resulted in a hypoxic tumor microenvironment and prevented metastasis.

Primary Extraskeletal Osteosarcoma of Liver: Case of Report

BackgroundExtraskeletal osteosarcoma (ESOS) is a highly malignant osteosarcoma that occurs in extraskeletal tissues. It often affects the soft tissues of the limbs. ESOS is classified as primary or secondary ESOS. Case presentationwe report a case of primary hepatic osteosarcoma in a 76-year-old male patient. The patient had a giant cystic-solid mass in the right liver that was evident on ultrasound and computed tomography. Postoperative pathology and immunohistochemistry of the mass, which was surgically removed, suggested fibroblastic osteosarcoma. No other abnormal lesions were found. Therefore, the patient was diagnosed with primary hepatic osteosarcoma. The hepatic osteosarcoma reoccurred 48 days after surgery, resulting in significant compression and narrowing of the hepatic segment of the inferior vena cava. Consequently, the patient underwent stent implantation in the inferior vena cava and transcatheter arterial chemoembolization. Unfortunately, the patient died of postoperative multiple organ failure.ConclusionsHepatic osteosarcoma is a rare mesenchymal tumor with a short course and a high likelihood of metastasis and recurrence. If a biopsy were to return osteoid in a large liver tumor, ESOS would be suspected. However, there is no evidence-based treatment plan to date. Surgical resection combined with adjuvant chemoradiotherapy seems to be the best treatment option.

Primary osteosarcoma of the uterus: a report of two cases

Primary extraskeletal osteosarcoma is an uncommon disease and has been reported to affect the uterus only rarely. Less than 20 cases have so far been reported in the English literature. The common clinical presentation is heavy bleeding per vaginam, and in virtually all cases, the diagnosis has been made at an advanced stage of the disease. Various authors have recommended adjuvant chemotherapy, but outcomes have so far been uniformly poor, with survival extended by months rather than years. We present two cases of this rare condition, which were diagnosed four months apart within our histopathology laboratory andconfirmed the very late presentation of the disease in one and the poor survival of both patients.

Primary extraskeletal osteosarcoma of sigmoid mesocolon: a case report and a review of the literature

Background Extraskeletal osteosarcoma (ESOS) is a rare mesenchymal malignancy, which produces osteoid, bone, or chondroid material and is located in the soft tissue without attachment to skeletal bones and periosteum. One of the things that ESOS originated from mesentery is much rarer. Case presentation A 75-year female had a history of pain in the left lower abdomen for more than 4 months. Abdominal computerized tomography (CT) and magnetic resonance imaging revealed a large, irregular, and solid-cystic mass (largest diameter was 11.5 cm). The tumor was radically removed during an open operation. It was composed of abundant osteoid and polyhedral-shaped tumor cells with high atypia and high mitotic activity microscopically. The final pathological diagnosis was osteoblastic osteosarcoma, arising from the sigmoid mesocolon with negative margins. A 9-month follow-up by CT exhibited signs of peritoneal metastasis. Conclusions Given the rarity of cases of mesenteric ESOS, diagnosis mainly depended on pathology findings or should be taken into consideration when the mesenteric mass was found. Its most effective treatment had not been determined, with surgical excision being generally accepted. Ensuring negative surgical margins may be an important factor affecting prognosis.

Juvenile dermatomyositis in Thai children: Retrospective review of 30 cases from a tertiary care center

Background: Juvenile dermatomyositis is a rare condition, but it is the most common idiopathic inflammatory myopathy in pediatric patients. Aim: To study the clinical manifestations, investigations, treatment, clinical course, and outcomes of juvenile dermatomyositis in Thai children. Method: This retrospective study included juvenile dermatomyositis patients treated at Siriraj Hospital, a 2,300-bed national tertiary referral center in Bangkok, Thailand, from 1994 to 2019. Results: Thirty patients (22 females and 8 males) were included with a female to male ratio of 2.7:1. Median age at diagnosis was 5.1 years (range, 2.6-14.8 years). Median duration of illness before diagnosis was 6.5 months (range, 0.3-84.0 months). Acute and subacute onset occurred in the majority of patients. Presenting symptoms included muscle weakness in 27/30 (90%), skin rash in 26/30 (86.7%), muscle pain in 17/26 (65.4%), and arthralgia in 4/18 (22.2%) of patients. Dermatologic examination revealed Gottron’s rash, heliotrope rash, and periungual telangiectasia in 25/30 (83.3%), 21/30 (70.0%), and 15/24 (62.5%) of patients, respectively. Interestingly, scalp dermatitis was found in 8/21 (38.1%) of patients. The most commonly used treatment regimen in this series was a combination of prednisolone and methotrexate. During the median follow-up of 3.1 years (range, 0.0-18.5 years), only one-third of patients were seen to have monocyclic disease. Extraskeletal osteosarcoma at a previous lesion of calcinosis cutis was observed in one patient at 12 years after juvenile dermatomyositis onset. Limitations: This was a retrospective single-center study, and our results may not be generalizable to other healthcare settings. Prospective multicenter studies are needed to confirm the findings of this study. Conclusion: juvenile dermatomyositis usually poses a diagnostic and therapeutic challenge, which can be compounded by the ethnic variations in the clinical presentation, as observed in this study. Asian patients tend to present with acute or subacute onset of disease, and arthralgia and/or arthritis are less common than in Caucasian patients. Scalp dermatitis is not uncommon in pediatric juvenile dermatomyositis patients. An association between juvenile dermatomyositis and malignancy, though rare, can occur.

Case Report: Primary Extraskeletal Osteosarcoma in the Lung and Pulmonary Artery

Extraskeletal osteosarcoma is an uncommon and high-grade soft tissue malignancy. The incidence is even lower when the lung and pulmonary artery are the primary site. The purpose of this report is to present the radiological features of this neoplasm in a 52-year-old man. In our case, contrast-enhanced CT and 3D-CT reconstruction clearly showed the primary lesion and its invasion into surrounding tissues. Although wide local excision of the primary tumor is the treatment of choice, local recurrence and metastasis rates remain high, and this progression can be clearly shown on CT and SPECT/CT examinations.