Recurrent pneumothorax in a patient with liposarcoma as either a complication of lung micrometastasis or a potential adverse event from antibiotic therapy: A case report.

Spontaneous pneumothorax (PNX) is an infrequent manifestation of primary lung cancer, soft tissue sarcoma and metastasis. There are no easily accessible data in the literature regarding the correlation between PNX and antibiotics, whereas cases of PNX following chemotherapy have been observed. Only 1-10% of treatment-related adverse events are estimated to be reported to the Food and Drug Administration. The present study described a case of PNX of the left lung in a 70-year-old treatment-naive patient with retroperitoneal liposarcoma. The PNX developed after 8 days of treatment with levofloxacin and after 6 days of piperacillin/tazobactam treatment for a suspicious inflammatory area in the right lung detected by an FDG-PET scan before the patient started chemotherapy. A chest CT scan confirmed the presence of metastasis in the right lung, but neither FDG-PET/CT nor CT showed metastatic disease in the left lung. A total of 14 days after the end of the third cycle of doxorubicin (2 months after the initial diagnosis of PNX), the patient manifested a massive PNX of the right lung. In conclusion, these findings indicated that spontaneous PNX could be linked to the use of some antibiotics.

Role of DCE-MR in predicting breast cancer subtypes.

OBJECTIVE: The purpose of this retrospective study is to find a correlation between dynamic contrast-enhanced MR features with histological, immunohistochemical and loco-regional characteristics of breast cancer. MATERIALS AND METHODS: A total of 149 patients with histopathologically confirmed invasive breast carcinoma underwent MR imaging. Histological analysis included: histological features (histological type, necrosis, vascular invasion and Mib-1), immunohistochemical characterization (immunophenotype, receptor status, HER2-neu and grading) and loco-regional characteristics (T and N). The kinetic MR features analyzed were: curve type, maximum enhancement, time to peak, wash-in and wash-out rate, brevity of enhancement and area under curve. RESULTS: MRI kinetic parameters and immunohistological features were compared using chi square test, two-tailed student t test and Anova test, with p = 0.05 level of significance. Vascular invasion was shown to be significantly related to time to peak (p = 0.02). The immunohistotype was shown to be significantly related with maximum enhancement (p = 0.05), time to peak (p = 0.04) and wash-in rate (p = 0.01). ER status correlates with maximum and relative enhancement (p = 0.004 and p = 0.028), wash-in rate (p = 0.0018) and area under curve (p = 0.006). PR status was significantly related to time to peak (p = 0.048) and wash-in rate (p = 0.05). CONCLUSION: Maximum enhancement absolute and relative, time to peak, wash-in rate and area under the curve significantly correlate with several prognostic factors, like ER status, immune profile and tumoral vascular invasion, and may predict the aggressiveness of the tumor.

Impact of low-energy CT imaging on selection of positive oral contrast media concentration.

OBJECTIVES: To determine to what extent low-energy CT imaging affects attenuation of gastrointestinal tract (GIT) opacified with positive oral contrast media (OCM). Second, to establish optimal OCM concentrations for low-energy diagnostic CT exams. METHODS: One hundred patients (38 men and 62 women; age 62 ± 11 years; BMI 26 ± 5) with positive OCM-enhanced 120-kVp single-energy CT (SECT), and follow-up 100-kVp acquisitions (group A; n = 50), or 40-70-keV reconstructions from rapid kV switching-single-source dual-energy CT (ssDECT) (group B; n = 50) were included. Luminal attenuation from different GIT segments was compared between exams. Standard dose of three OCM and diluted solutions (75%, 50%, and 25% concentrations) were introduced serially in a gastrointestinal phantom and scanned using SECT (120, 100, and 80 kVp) and DECT (80/140 kVp) acquisitions on a ssDECT scanner. Luminal attenuation was obtained on SECT and DECT images (40-70 keV), and compared to 120-kVp scans with standard OCM concentrations. RESULTS: Luminal attenuation was higher on 100-kVp (328 HU) and on 40-60-keV images (410-924 HU) in comparison to 120-kVp scans (298 HU) in groups A and B (p < 0.05). Phantom: There was an inverse correlation between luminal attenuation and X-ray energy, increasing up to 527 HU on low-kVp and 999 HU on low-keV images (p < 0.05). 25% and 50% diluted OCM solutions provided similar or higher attenuation than 120 kVp, at low kVp and keV, respectively. CONCLUSIONS: Low-energy CT imaging increases the attenuation of GIT opacified with positive OCM, permitting reduction of 25%-75% OCM concentration.