Tracheal regeneration: evidence of bone marrow mesenchymal stem cell involvement.

OBJECTIVES: Recent advances in airway transplantation have shown the ability of ex vivo or in vivo tracheal regeneration with bioengineered conduits or biological substitutes, respectively. Previously, we established a process of in vivo-guided tracheal regeneration using vascular allografts as a biological scaffold. We theorized that tracheal healing was the consequence of a mixed phenomenon associating tracheal contraction and regeneration. The aim of the present study was to determine the role that bone marrow stem cells play in that regenerative process. METHODS: Three groups of 12 rabbits underwent a gender-mismatched aortic graft transplantation after tracheal resection. The first group received no cells (control group), the second group had previously received autologous green fluorescent protein-labeled mesenchymal stem cell transplantation, and the third group received 3 labeled mesenchymal stem cell injections on postoperative days 0, 10, and 21. RESULTS: The clinical results were impaired by stent complications (obstruction or migration), but no anastomotic leakage, dehiscence, or stenosis was observed. The rabbits were killed, and the trachea was excised for analysis at 1 to 18 months after tracheal replacement. In all 3 groups, microscopic examination showed an integrated aortic graft lined by metaplastic epithelium. By 12 months, immature cartilage was detected among disorganized elastic fibers. Positive SRY gene detection served as evidence for engraftment of cells derived from the male recipient. EF-green fluorescent protein detection showed bone marrow-derived mesenchymal stem cell involvement. CONCLUSIONS: The results of the present study imply a role for bone marrow stem cells in tracheal regeneration after aortic allografting. Studies are necessary to identify the local and systemic factors stimulating that regenerative process.

Inflammatory myofibroblastic tumor of the lung: a benign lesion with aggressive behavior.

Inflammatory myofibroblastic tumor is a rare solid tumor that most often affects children and young adults. They present as myofibroblastic cell proliferations accompanied by inflammatory cells made up mostly of plasma cells. Although benign, the tumor may be very aggressive locally. In this report we describe a 22-year-old woman with primary invasive myofibroblastic tumor of the left lower lobe leading to a left pneumonectomy.

A wandering spleen presenting as a hypogastric mass: case report.

Wandering spleen is a rare condition characterized by the absence or underdevelopment of one or all of the ligaments that hold the spleen in its normal position in the left upper quadrant of the abdomen. It is an uncommon clinical entity that mainly affects children. Among adults it most frequently affects women of reproductive age, in whom acquired laxity of the splenic ligaments is usually the cause. Patients with a wandering spleen may be asymptomatic, present with a movable mass in the abdomen, or have chronic or intermittent abdominal pain because of partial torsion and spontaneous detorsion of the spleen. A 26-year-old woman was admitted to our hospital with vomiting and abdominal pain. Abdominal examination revealed a large ovoid hypogastric mass. A CT scan showed a wandering spleen in the hypogastric region. Exploratory laparotomy revealed an ischemic spleen. A total splenectomy was performed.

Exceptional cause of bowel obstruction: rectal endometriosis mimicking carcinoma of rectum--a case report.

Endometriosis with intestinal serosal involvement is not uncommon in women of childbearing age. However, endometriosis presenting as colon obstruction is rare and occurs in less than 1% of cases. The Lack of pathognomonic signs makes the diagnosis difficult, mostly because the main differential diagnosis is with neoplasm, even during the intervention. Reported here is a case of a 35-year -old woman presenting with bowel obstruction due to rectal endometriosis. The patient presented signs and symptoms of bowel obstruction. Colonoscopy and radiological findings were suggestive of rectal carcinoma. Surgeons performed an anterior resection with right salpingectomy. Histopathology diagnosed bowel endometriosis. This case demonstrates the difficulty of establishing an accurate pre- and intra- operative diagnosis and the ability of intestinal endometriosis to mimic colon cancer.

Hemothorax as the clinical presentation of a pancreaticopleural fistula: report of a case.

Pancreaticopleural fistula is a rare complication of acute pancreatitis with pancreatic pseudocyst. We report the case of a 39-year-old man admitted for respiratory distress. Chest X-ray showed a pleural effusion, and thoracentesis yielded bloody fluid. Computed tomography (CT) scan showed a multiloculated pleural effusion and sagittal reconstruction revealed a fistulous tract between the pleura and a pancreatic pseudocyst. We treated the acute hemothorax complicating the pancreaticopleural fistula by performing urgent thoracotomy with the evacuation of blood and clots and lung decortication. We also gave the patient somatostatin and performed endoscopic retrograde cholangiopancreatography with sphincterotomy, and placed a pancreatic stent. The patient recovered well.