Application of 3D Mass Spectrometry Imaging to TKIs.

Mass spectrometry imaging (MSI) allows visualization of endogenous and exogenous compound in tissue sections based on its molecular mass. The 3D reconstruction by MSI provides a more informative description of the tumor drug distribution compared to the high-performance liquid chromatography method, highlighting the heterogeneity of intratumor drug concentration. This additional information can be important in understanding chemoresistance to target agents. Here, we present the 3D visualization of the tyrosine kinase inhibitor (TKI), imatinib, in a xenograft model of resistant malignant pleural mesothelioma.

Mediastinoscopy in the treatment of mediastinal cysts.

OBJECTIVE: Primary cysts constitute 25% of all masses in the mediastinum. Because radiological investigations are often inconclusive, many adults require mediastinoscopy, thoracotomy, video-assisted thoracic surgery, or computed tomography-guided transbronchial, transesophageal, or transcutaneous aspiration to confirm the cystic nature of these lesions. Minimally invasive procedures fail when the cyst contents are gelatinous and mucoid (failure to aspirate) or when the cyst wall continues to secrete fluid. Though Pursel reported mediastinoscopic extirpation of benign cysts 35 years ago, it remains a "therapeutic curiosity" with sporadic reports of its usage. We report 2 successful mediastinal cyst extirpations performed as outpatient procedures and review the literature with regards to its management. METHODS: A rigid, 8-mm mediastinoscope was inserted into the anterior mediastinum following the creation of a 2-cm suprasternal incision and dissection along the anterior surface of the trachea. After aspiration, cytology of the contents revealed their benign nature. Right paratracheal cysts in 2 adult males were successfully removed mediastinoscopically by blunt and sharp dissection. RESULTS: Histopathology revealed benign mesothelial cysts in both instances. Both patients had an uncomplicated procedure and were discharged within 23 hours. No other pathology was detected on mediastinoscopy, and follow-up at 3 months and 6 months has revealed no recurrence. CONCLUSION: Mediastinoscopic cyst removal is a minimally invasive procedure with a very low morbidity and mortality rate. Morbidity, recovery, and discharge times are much less than those of more invasive procedures (video-assisted thoracic surgery / thoracotomy). We suggest that it should be the first-choice procedure for the excision of appropriately located benign mediastinal cysts.

Peritoneal carcinomatosis: role of (18)F-FDG PET.

UNLABELLED: Peritoneal carcinomatosis can be difficult to diagnose, as CT is insensitive, with peritoneal biopsy and lavage often subject to problems of sampling error. The aim of our study was to evaluate the role of (18)F-FDG PET in detecting peritoneal carcinomatosis in patients with stomach, ovarian, and adrenal cancer and mesothelioma and to compare the results with CT scans in the same patient group. Our secondary aim was to identify characteristic patterns of abdominal (18)F-FDG uptake in biopsy-proven peritoneal disease and to correlate these patterns with available histologic and anatomic findings after surgery and structural imaging. METHODS: The medical records of 88 patients with stomach (n = 48), ovarian (n = 13), and adrenal cancer (n = 6) and mesothelioma (n = 21) were reviewed for the presence of peritoneal tumor on (18)F-FDG PET and CT scans. The results were correlated with either contemporaneous peritoneal biopsy or ascitic aspirate or with radiographic or clinical follow-up if histology was negative or unavailable. Of 24 patients with suspected peritoneal tumor, 17 had biopsy-proven findings of peritoneal disease. RESULTS: Of the 24 patients with suspected peritoneal tumor, (18)F-FDG PET was positive in 14 patients, with 1 of these scans being false-positive, CT was positive in 10 patients, and either PET or CT was positive in 18 patients. This yielded sensitivities of 57% (13/23), 42% (10/23), and 78% (18/23), with uniformly high positive predictive values of 93% (13/14), 100% (10/10), and 95% (18/19), respectively. We identified 2 distinctly abnormal scintigraphic patterns of focal and uniform (18)F-FDG uptake corresponding to nodular and diffuse peritoneal disease on pathologic examination. CONCLUSION: (18)F-FDG PET adds to conventional imaging in the staging of peritoneal carcinomatosis. It is also a useful diagnostic tool when peritoneal biopsy is either unavailable or inappropriate. We have identified 2 distinct scintigraphic patterns that appear to predict the presence of either nodular or diffuse peritoneal pathology.

Peritoneal inclusion cysts in adolescent females: a clinicopathological characterization of four cases.

STUDY OBJECTIVE: To identify adolescent females with peritoneal inclusion cysts and characterize the clinicopathologic features. DESIGN: Observational and chart review along with immunohistochemical studies. SETTING: University pediatric and adolescent clinic. RESULTS: Medical records of all subjects, ages 10-18 years, diagnosed with peritoneal inclusion cysts over a 4-year period were retrospectively reviewed. Four patients, ages 11-16 years (mean, 13.8 yrs) were identified. Pelvic pain was the most common presenting symptom. No palpable abdominal or pelvic masses were detected. However, pelvic lesions were identified by radiographic studies in three of the four patients. Half experienced tenderness on examination. With one exception, all had a prior history of abdominal surgery. Twelve peritoneal inclusion cysts were identified, ranging from 1 cm to 7 cm in greatest diameter. Most were uninvolved in coexisting adhesions and non-adherent to pelvic or abdominal structures. Each had a well-defined pedicle connection to the peritoneum. No associated complications were identified. Their appearance conformed to established morphologic and immunohistochemical criteria, although accompanying mesothelial-associated changes occasionally reported in other populations were not detected. No recurrences were recorded. CONCLUSION: Young female adolescents with peritoneal inclusion cysts share presenting symptoms and histories of previous abdominal surgery similar to those reported in older female adolescents and adults. A palpable mass may not be detected on examination, but can often be identified using radiographic studies. Our cases differ from previous reports by smaller cyst size, presence of a pedicle, and uncomplicated gross and microscopic appearances. Additionally, local recurrences and associated complications occurred less than reported in adults.