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.

Primary Extraskeletal Osteosarcoma of Sigmoid Mesocolon: A Case Report and a Review of the Literature

Background: Extraskeletal osteosarcoma (ESOS) is a very rare mesenchymal malignancy, characterized by the production of osteoid, bone or chondroid material and typically 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 with a more than 4-months history of pain in the left lower abdomen. Abdominal computerized tomography and magnetic resonance imaging revealed a large, irregular and solid-cystic mass, which largest diameter was 11.5cm. The tumor was radically removed during open operation. The tumor 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. The patient was followed up 5 months after surgery and found no signs of systemic metastasis Conclusion: 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 was generally accepted. Negative surgical margin may be an important factor affecting the prognosis.

Intraperitoneal liposarcoma: a rare presentation

Liposarcoma are frequently seen in the retroperitoneum. It is of four types pathologically: Well-differentiated, dedifferentiated, myxoid and pleomorphic. Well-differentiated is the most common type. Dedifferentiated has the worst prognosis. Reports of Liposarcoma arising from the intraperitoneal sites such as stomach, omentum, mesentery and sigmoid mesocolon are rare. A 47 year old gentleman presented with pain in abdomen and abdominal distention, had a provisional diagnosis of GIST, intra-peritoneal liposarcoma. Imaging revealed a well-defined encapsulated abdominal mass indicative of liposarcoma with fibrous differentiation/fibro-lipoma. On surgery a well encapsulated mass was excised completely arising from the greater curvature of stomach. The mass on histopathological examination indicated features suggestive of liposarcoma (well-differentiated) with IHC markers positive for S100, CDK4 and MDM2. A diagnosis of intraperitoneal liposarcoma form greater curvature of stomach was made. This was an exceedingly rare presentation of liposarcoma arising from the greater curvature of stomach with differential diagnosis of GIST which was ruled out with histopathological features and negative CD117 and CD34. Thus to conclude liposarcoma being quite common retroperitoneal tumor, has an exceedingly rare occurrence from intraperitoneal sites and should be taken as an exceedingly rare differential diagnosis for mass per abdomen.

MUCINOUS MESENTERIC CYST OF SIGMOID MESOCOLON : A RARE ENTITY

Mesenteric cysts are rare and occur in patients of any age. They are asymptomatic and found incidentally or during the management of their complications. They commonly originate from the small bowel mesentery, although a proportion of them have been found to originate from the mesocolon (24%) and the retroperitoneum [1] [2,3,4,5] (14.5%). A mesenteric cyst originating in the sigmoid mesocolon is a very rare nding. They are a rare cause of abdominal pain and are discovered incidentally. If symptomatic, patients with these cysts present with abdominal pain, vomiting and low backache. Performing a thorough physical examination and conducting radiological investigations like ultrasonography (USG), computed tomography (CT) are keys in diagnosing the mesenteric cysts.

Laparoscopy-Assisted Repair for Intersigmoid Hernia

Intersigmoid hernia is a rare clinical entity. Only 6 cases of laparoscopic repair for intersigmoid hernia have been reported since 1977. We herein report such a case, which was successfully diagnosed preoperatively and treated with laparoscopic repair. A 50-year-old man with a chief complaint of abdominal pain and vomiting was admitted for the treatment of small bowel obstruction. The patient had no history of abdominal surgery. Computed tomography showed a dilated small bowel and a closed loop of small bowel dorsal to the sigmoid colon and the sigmoid mesocolon. With a diagnosis of an incarcerated internal hernia, the patient underwent emergency laparoscopy-assisted surgery. Laparoscopy showed that the ileum had herniated into the intersigmoid fossa, and therefore the patient was diagnosed with an intersigmoid hernia. Because bowel ischemia was not observed, we reduced the incarcerated small bowel, and the hernial defect was widely opened. After operation, the patient developed ileus and was treated with transnasal ileus tube. Thereafter, the patient made a satisfactory recovery and was discharged on postoperative day 21. The patient is in good general condition without ileus 42 months postoperatively.

The “Omega sign”: a new radiological sign for a rare type of internal hernia involving the sigmoid mesocolon

The transmesosigmoid hernia is a rare type of sigmoid mesocolon hernia. Its presentation is non-specific and thus hardly ever preoperatively diagnosed. Its diagnosis often requires surgical corroboration. This case report aims to improve on the preoperative diagnosis with a proposed observed sign on CT. All literature reviewed described radiological findings related to the small bowel; thus, features of small bowel obstruction was the “hallmark” of internal hernias. This paper intends to describe the features of the sigmoid mesocolon internal hernias, illustrate and propose a never reported configuration of the sigmoid colon. This sigmoid colon configuration has a resemblance to the omega sign. We intend to present a new hallmark sign, which may serve as a clue in the identification of internal hernias involving the sigmoid mesocolon.