Complete spontaneous remission of small cell lung cancer in the absence of specific treatment: A case report.

Small cell lung cancer (SCLC) is a unique tumor that has a distinct clinical behavior and dismal prognosis. If untreated, it can become aggressively malignant, and life expectancy could be limited to weeks. Spontaneous regression of lung cancer has rarely been reported, and among them SCLC is even rarer. The underlying mechanisms of spontaneous regression are poorly understood. Here, we report a case of complete spontaneous SCLC remission in an elderly patient.

Community-acquired Achromobacter xylosoxidans infection presenting as a cavitary lung disease in an immunocompetent patient.

Achromobacter xylosoxidans is a gram-negative bacterium that can oxidize xylose. It is commonly found in contaminated soil and water but does not normally infect immunocompetent humans. We report a case of a cavitary lung lesion associated with community-acquired A. xylosoxidans infection, which mimicked pulmonary tuberculosis or lung cancer in an immunocompetent man. The patient was hospitalized due to hemoptysis, and chest computed tomography (CT) revealed a cavitary lesion in the superior segment of the left lower lobe. We performed bronchoscopy and bronchial washing, and subsequent bacterial cultures excluded pulmonary tuberculosis and identified A. xylosoxidans. We performed antibiotic sensitivity testing and treated the patient with a 6-week course of amoxicillin/clavulanate. After 2 months, follow-up chest CT revealed complete resolution of the cavitary lesion.

Squamous cell carcinoma of the lung with simultaneous metastases to peritoneum and skeletal muscle.

Skeletal muscle and peritoneum are rare sites of metastases from lung cancer. We report a case of squamous cell lung cancer with concurrent metastases to skeletal muscle and peritoneum. A 71-year-old man was diagnosed with squamous cell carcinoma of the right lower lobe with metastasis to the right hilar lymph node at clinical stage T3N1M0. Because of poor performance status and comorbidity, he only received radiation therapy. Positron emission tomography-computed tomography for mid-assessment of response showed two abnormal hypermetabolic lesions in the peritoneum of the left upper quadrant area and the left thigh muscle. We performed a needle-approach biopsy in each lesion and found both of the lesions were metastases from lung cancer. The patient died after two months.

A case of fulminant community-acquired Acinetobacter baumannii pneumonia in Korea.

Acinetobacter baumannii (AB) is a common pathogen found in patients with hospital-acquired pneumonia all over the world. Community-acquired AB pneumonia, however, is very rare and has seldom been reported in Asia-Pacific countries. Community-acquired AB pneumonia has a fulminant course and is associated with a higher mortality than hospital-acquired AB pneumonia. In Korea, no case of fatal community-acquired AB pneumonia has been reported to date. Here, we describe the first fatal case of fulminant community-acquired AB pneumonia in Korea.

Bronchomediastinal fistula detected accidently during palliative radiation therapy.

Bronchomediastinal fistula is an extremely rare complication resulting from diseases such as mediastinitis or mediastinal malignancies. In patients with lung cancer, bronchomediastinal fistula formation has rarely been reported, except during post-chemotherapy or post-radiation therapy complications. An 84-year-old visited our hospital to receive palliative radiation therapy for squamous cell carcinoma of the right main bronchus T4N2M1a. During an early course of radiation therapy, chest computed tomography (CT) scans revealed bronchomediastinal fistula between the right main bronchus and the enlarged sub-carinal lymph nodes. Radiation therapy was, therefore, discontinued and the patient received only supportive care.

A Case of Streptococcus suis Infection Causing Pneumonia with Empyema in Korea.

Streptococcus suis causes meningitis and sepsis in pigs, but human infection has increased over the past few years in those who are exposed to pigs or raw pork. Most cases have occurred in Southeast Asia, but only two cases have been reported in South Korea, presenting with arthritis and meningitis. Here, we report a rare case of S. suis infection, a 60-year-old sailor, who visited the emergency room presenting septicemia, pneumonia with empyema and meningitis, showed full recovery; however, neurologic sequale of severe cognitive dysfunction was present after the usage of antibiotics and percutaneous drainage. S. suis was isolated from blood and pleural fluid and the strain was susceptible to penicillin and vancomycin. Increased awareness of S. suis infection and prevention are warranted.

Measurement of nasal nitric oxide is useful for the diagnosis of sinusitis-induced prolonged cough.

Upper airway cough syndrome (UACS), the most common cause of prolonged cough, is diagnosed based on clinical findings without specific diagnostic test. The concentration of nitric oxide in nasal cavity air (nNO) is influenced by allergic rhinitis and/or sinusitis, both of which are common causes of UACS. We measured nNO levels in patients with UACS and those with other causes. We also examined the usefulness of measuring nNO for differentiating patients with sinusitis from those without sinusitis. The study included 93 adult patients with prolonged cough lasting more than threeweeks. Etiologies of cough were identified and nNO was measured at the initial investigation. UACS was diagnosed in 58 patients (62.4%), and sinusitis was identified in 11 (19.0%) of the 58 patients with UACS. Levels of nNO in UACS did not differ from non-UACS etiologies (316.2±129.2 vs. 334.9±88.2 ppb; p=0.452), suggesting that the measurement of nNO could not discriminate UACS from other etiologies of prolonged cough. However, patients with sinusitis showed significantly decreased nNO levels (190.1±114.8ppb) compared with patients with UACS without sinusitis (345.7±114.6ppb; p<0.001) and non-UACS patients (334.9±88.2 ppb; p<0.001). In a receiver operating characteristic curve analysis for the diagnosis of sinusitis in prolonged cough, the best sensitivity (73.2%) and specificity (81.8%) were obtained with a nNO cutoff value of 279.0 ppb. These findings imply that the measurement of nNO could be useful for diagnosis of prolonged cough associated with sinusitis.

Molecular mechanisms of cellular proliferation in acute myelogenous leukemia by leptin.

Leptin acts as a growth factor in normal cells as well as in various types of cancer cells. We investigated the effects of leptin on human acute myelogenous leukemia (AML) cells. Leptin stimulated the proliferation of HEL cells through the phosphorylation of STAT3 and ERK1/2. The blocking of STAT3 phosphorylation with the specific inhibitor, AG490, significantly reduced leptin-induced ERK1/2 phosphorylation and cellular proliferation, whereas the blocking of ERK1/2 activation by the specific ERK1/2 inhibitor, PD98059, did not affect the STAT3 phosphorylation or leptin-induced proliferation in HEL cells. Furthermore, knockdown of leptin receptor (OB-R) expression with stealth RNA interference (RNAi) reduced the leptin-induced proliferation of HEL cells and also significantly attenuated leptin-induced STAT3 and ERK1/2 activation. These results suggest that leptin promotes AML cell growth by activating STAT3 and MAPK, although not directly dependent on ERK.