Lorlatinib Therapy for Rapid and Dramatic Control of Brain and Spinal Leptomeningeal Metastases From ALK-Positive Lung Adenocarcinoma

We report a patient with severe neurological deterioration due to leptomeningeal metastases involving brain and spinal cord from anaplastic lymphoma kinase (ALK)-positive lung adenocarcinoma, managed rapidly and successfully with lorlatinib therapy. A 48-year-old male patient presented with acute mental deterioration, severe headache, and weakness of both legs. The patient’s previous medical history included cerebral metastases from ALK-positive lung adenocarcinoma, which had been successfully managed via whole brain radiation therapy and gamma knife radiosurgery one year and three months before, respectively. Physical examination revealed neck stiffness and paraparesis with motor grade I.Gadolinium-enhanced brain MRI showed newly developed leptomeningeal enhancement along cerebellar folia, and whole spine MRI revealed similar leptomeningeal metastasis along the whole spinal axis. Lorlatinib was started orally with a dose of 100 mg/day. The patient showed rapid clinical improvement after one week. The patient was alert and the headache disappeared, while the paraparesis improved to normal ambulatory status. Two months of lorlatinib treatment resulted in almost complete disappearance of previous leptomeningeal enhancement of brain and spinal cord, and absence of newly developed metastatic lesions in the central nervous system, based on MRI results. The patient had been regularly followed with ongoing lorlatinib therapy for 5 months without any systemic complications or neurological abnormality. Conclusively, lorlatinib could be a rapid and effective treatment for patients with central nervous system leptomeningeal metastases arising from ALK-positive lung cancer.

Tobacco Growth Promotion by the Entomopathogenic Fungus, Isaria javanica pf185

Isaria javanica pf185 is an important entomopathogenic fungus with potential for use as an agricultural biocontrol agent. However, the effect of I. javanica pf185 on plant growth is unknown. Enhanced tobacco growth was observed when tobacco roots were exposed to spores, cultures, and fungal cell-free culture supernatants of this fungus. Tobacco seedlings were also exposed to the volatiles of I. javanica pf185 in vitro using I-plates in which the plant and fungus were growing in separate compartments connected only by air space. The length and weight of seedlings, content of leaf chlorophyll, and number of root branches were significantly increased by the fungal volatiles. Heptane, 3-hexanone, 2,4-dimethylhexane, and 2-nonanone were detected, by solid-phase micro-extraction and gas chromatography-mass spectrophotometry, as the key volatile compounds produced by I. javanica pf185. These findings illustrate that I. javanica pf185 can be used to promote plant growth, and also as a biocontrol agent of insect and plant diseases. Further studies are necessary to elucidate the mechanisms by which I. javanica pf185 promotes plant growth.

Dual Biocontrol Potential of the Entomopathogenic Fungus, Isaria javanica, for Both Aphids and Plant Fungal Pathogens

Dual biocontrol of both insects and plant pathogens has been reported for certain fungal entomopathogens, including Beauveria bassiana and Lecanicillum spp. In this study, we demonstrate, for the first time, the dual biocontrol potential of two fungal isolates identified by morphological and phylogenetic analyses as Isaria javanica. Both these isolates caused mortality in the greater wax moth, and hence can be considered entomopathogens. Spores of the isolates were also pathogenic to nymphs of the green peach aphid (Myzus persicae), with an LC₅₀ value of 10⁷ spores/mL 4 days after inoculation and an LT₅₀ of 4.2 days with a dose of 10⁸ spores/mL. In vitro antifungal assays also demonstrated a strong inhibitory effect on the growth of two fungi that are pathogenic to peppers, Colletotrichum gloeosporioides and Phytophthora capsici. These results indicate that I. javanica isolates could be used as novel biocontrol agents for the simultaneous control of aphids and fungal diseases, such as anthracnose and Phytophthora blight, in an integrated pest management framework for red pepper.

Analysis of Sentinel Lymph Node Biopsy in 500 Cases with Breast Cancer

PURPOSE: Sentinel lymph node biopsy has emerged as a new standard method of treatment in small-sized breast cancer and has allowed the elimination of unnecessary axillary lymph node dissection in patients with negative axillary lymph nodes metastasis. In sentinel lymph node biopsy, pathologic analysis can be scrutinized and accurate stage-diagnosis can be made with the methods of serial sectioning and immunohistochemical staining on routine basis. In this study, we tried to evaluate the accuracy of sentinel lymph node biopsy. METHODS: We evaluated 500 cases of sentinel lymph node biopsy operated at Samsung Medical Center between October 1995 and February 2004. Cases were categorized in 2 groups: cases operated during the period of learning curve (October 1995~December 1999) and the period of clinical application (January 2000~February 2004). RESULTS: Overall failure rate and false negative rate of sentinel node biopsy were 9% and 14.7% respectively. The failure rate of the period of learning curve and the period of clinical application were 15.3% and 5.6% respectively (P <0.01). In sentinel lymph node detection, combined blue dye and radioisotope method was superior to blue dye or radioisotope method. About 40% of lymph node metastases were found in patients with tumors more than 2 cm in size. Clinical findings including previous biopsy, multiple tumor, neo- adjuvant chemotherapy, obesity and old age were not absolute contraindications for sentinel node biopsy. CONCLUSION: Sentinel lymph node biopsy can be an accurate and reliable method to examine the status of axillary nodes in a small breast cancer.

Endovascular Treatment of Arteriovenous Fistula with Pseudoaneurysm at Popliteal Fossa Using a PTFE Stent-graft: A Case Report

We report the successful treatment of a postoperative pseudoaneurysm of a popliteal artery, which was associated with an arteriovenous fistula to the popliteal vein using an endovascular placement of a PTFE-covered stent graft. After a one-month follow-up, there was an in-stent stenosis, which was managed by balloon angioplasty. The patient was well with mild leg discomfort after a 3-month follow-up.

Asymptomatic Primary Hematuria in Children

PURPOSE: Present study has been undertaken to determine the distribution of various renal diseases causing asymptomatic hematuria in children and to evaluate the benefit of doing renal biopsy in these children. METHODS: Study population consisted of 146 children with asymptomatic primary hematuria who had been admitted to the pediatric department of Kyungpook National University Hospital for the past 4 years from 1999 to 2002. In 122 out of 146 cases, renal biopsy was performed percutaneously and in 24 out of 146 cases, diagnosed as idiopathic hypercalciuria, oral calcium loading test was performed. RESULTS: The age(mean+/-SD) at onset or discovery of hematuria of the 146 children included in this study was 8.0+/-3.2 years and the proportion of boys and girls was 54.8% and 45.2%, respectively. In 76 out of 146 cases(52%), asymptomatic hematuria was first diagnosed by school urinalysis screening. The proportion of histopathologic findings based on 122 biopsies was as follows : Thin Glomerular Basement Membrane(TGBM) 73 cases(50%); IgA nephropathy 20 cases(14%); Alport syndrome 6 cases(4%); Membranous Glomerulonephropathy(MGN) 4 cases(3%); Membranoproliferative Glomerulonephritis(MPGN) 2 cases(1%); IgA nephropathy with TGBM 3 cases(2%); "normal" glomeruli 14 cases(10%). Twenty four cases (16%) were diagnosed as idiopathic hypercalciuria. During follow-up periods, 15% of 146 cases became hematuria-free and renal function did not deteriorate in any cases. CONCLUSION: Unless hematuric children manifest poor prognostic indicators for renal survival, we would recommend long term regular follow-up prior to a renal biopsy.

The Aging-related Change of Responses to TSH in Thyroid Cells / 대한내분비학회지

BACKGROUND: To understand the mechanism of aging-related changes of the thyroid, the differentiated functions and growth of thyroid cells in response to TSH were investigated using aged or young thyrocytes. METHODS: FRTL-5 cells, with less than 10 or more than 45 passages, were used. After treatment with 1 U/L TSH or 1-100 mM NaI, the cAMP generation, iodide uptake, cellular proliferation or the expression of NIS mRNA or protein were measured. Sprague-Dawley rats were sacrificed at 5 and 16 weeks and 23 months, and their thyroids used for Northern blot analysis or immunohistochemistry of NIS. RESULTS: There were no differences in cAMP generation, iodide uptake, the proportions of G1/M or S phase, or intracellular DNA contents between the young and aged cells at basel levels. After TSH stimulation, these were increased in dose-dependent manners, with larger increments in the young cells. The changes in the NIS mRNA expression were similar in both the young and aged cells, but to a greater extent in the young cells. A similar phenomenon was observed in rat. However, the amount or intracellular distribution of NIS protein was not different. There was also no difference in the function or expression of NIS after treatment with a high dose of iodide. CONCLUSION: The aging-related decrease in the generation of cAMP might be thought of as one of the mechanisms of the decrement of iodide uptake or cellular proliferation with aging. The decreased expression of NIS mRNA seems to be the most important mechanism for the decreased iodide uptake capacity

Comparison of Clinical Characteristics between Primary Closure of Common Bile Duct and T-tube Drainage after Choledochotomy / 한국간담췌외과학회지

BACKGROUND/AIMS: In the management of choledocholithiasis, T-tube drainage was the most common treatment modality after common bile duct (CBD) exploration. However, the T-tube drainage has several problems and risk of complications such as abdominal discomfort, long duration of drainage, or bile leakage. We evaluated the effectiveness of primary closure of CBD after choledochotomy and the possibility of substitution for T-tube drainage. METHODS: Seventy six patients with choledocholithiasis who had undergone CBD exploration were enrolled in this study from January 1999 to March 2001. 20 patients among them had undergone primary closure of CBD with preoperative endoscopic nasobiliary drainage (ENBD) or percutaneous transhepatic biliary drainage (PTBD) in situ after exploration (primary closure group), 56 patients had undergone T-tube drainage (T-tube group). We compared the clinical characteristics and outcome between two groups. RESULTS: There was no difference in postoperative complication (19.6% vs. 20%), the mean amount of biliary drainage (326 ml/day vs. 320 ml/day) and the duration of hospitalization (11.6 day vs. 9.2 days) between the both groups. The duration of biliary drainage was significantly longer in the T-tube group (45.3 days) than in the primary closure group (9.2 days; p<0.01). The rate of remnant stone was higher in the T-tube group (32.1%) than the primary closure group (20%), there was not statistically significant. CONCLUSION: The primary closure of CBD with the preoperative biliary drainage was relatively safe and resulted in no difference of clinical outcome. Furthermore, this method induced going back early to normal life. These result suggest that the primary closure of CBD may be a feasible technique after choledochotomy when the patients are selected by specialized indications.

Effect of Intracavitary Injection of Urokinase in the Experimentally Induced Early Pyogenic Liver Abscess of the Rabbit

This study was carried out to assess the effects of intracavitary injection of urokinase in the early liver abscess (ELA) of the rabbits. ELAs were induced on 25 in 47 New Zealand rabbits, which were divided into two groups, with 15 in group A, and 10 in group B. Urokinase was injected into the ELA of group A, and normal physiologic saline into those of group B. One and a half hours after the injections, the rabbits were sacrificed and evaluated by pathologists for the degree of fibrosis of the ELA wall, and fibrinolysis in the ELA itself. Statistical analyses were performed between the two groups. The following ELA sizes for each group were obtained: Group A, 4.3 X 2.9-10.1 X 7.2 mm (mean 7.1 X 4.1 mm); Group B, 4.6 X 2.7-15.0 X 9.7 mm (mean 8.5 X 4.57 mm). Eleven (73%) in group A showed grade II fibrosis of ELA wall, and 8 (80%) in group B showed grade III fibrosis of ELA wall (p=0.002). On pathological analysis, 5 (46%) in group A showed grade II fibrin, and 8 (80%) in group B showed grade III fibrin, of the ELA (p=0.09). In conclusion, injection of urokinase, into the ELAs, can reduce the degree of fibrosis of abscess walls.

Evaluation of the Pedal Artery: Comparison of Three-dimensional Gadolinium-Enhanced MR Angiography with Digital Subtraction Angiography

PURPOSE: To compare the three-dimensional gadolinium-enhanced MR angiography with digital subtraction angiography (DSA) for evaluation of the pedal artery. MATERIALS AND METHODS: In 12 extremities of 11 patients, both digital subtraction angiography (DSA) and contrast-enhanced MR angiography (CE-MR angiography) were performed during the same week. Among ten of the 11 patients, the following conditions were present: atherosclerosis (n=4), diabetic foot (n=3), Buerger's disease (n=1), calciphylactic arteriopathy (n=1) and arteriovenous malformation of the foot (n=1). The remaining patient underwent angiography prior to flap surgery. For MR angiography, a 1.5T system using an extremity or head coil was used. A three-dimensional FISP (fast imaging with steady state precession) sequence was obtained before enhancement, followed by four sequential acquisitions (scan time, 20 secs; scan interval time, 10 secs) 10 seconds after intravenous bolus injection of normal saline (total 10 cc), following intravenous adminstration of gadolinium (0.02 mmol/kg, 3 ml/sec). Arterial segments of the ankle and foot were classified as the anterior or posterior tibial artery, the distal peroneal artery, the medial or lateral plantar artery, the pedal arch, and the dorsalis pedis artery. Two radiologists independently analysed visualization of each arteraial segment and the mean of visible arterial segments in one extreminty using CE-MR angiography and DSA. RESULTS: Among 84 arterial segments, 16 were invisible at both CE-MR angiography and DSA, while 39 were demonstrated by both modalities. Twenty-six segments were visible only at CE-MR angiography and three only at DSA. CE-MR angiography displayed a higher number of arterial segments than DSA (mean, 5.42 vs. mean 3.50, respectively), a difference which was statistically significant (p<0.000). The difference between each arterial segment was not statistically significant, except for the dorsalis pedis artery (t test, p<0.000). CONCLUSION: In that it provides additional information for the planning of treatment of lower-extremity arterial disease, three-dimensional CE-MR angiography is superior to DSA for evaluation of the pedal artery.

The Usefulness of Three-Dimensional Gadolinium-Enhanced MR Venography for the Evaluation of Varices in Lower Extremities

PURPOSE: To assess the performance of contrast-enhanced three-dimensional(3-D) magnetic resonance venography (MRV) of the pelvis and lower extremities in patients with varicose veins. MATERIALS AND METHODS: Ascending and MR venography were performed in seven legs of seven patients, and duplex Doppler sonography and MR venography in 15 legs of 12 patients, all referred for evaluation of varicose veins. For analysis, the venous system as revealed by ascending and MR venographic images was divided into 13 segments. For detection of reflux to the great saphenous vein, duplex Doppler sonography and MRV were performed. RESULTS: In ascending venography and MRV, 91 venous segments were potentially visible; both modalities depicted 78 of these, but failed to detect four. Ascending venography and MRV detected 17 and 19 varices, respectively. When two tourniquets were placed around the ankle and knee using the Valsalva maneuver, MRV and duplex Doppler sonography detected reflux in 8 of 11 and 13 of 15 legs, respectively. CONCLUSION: Contrast-enhanced 3-D MRV comprehensively displays the venous system of the lower extremities and permits assessment of varicose veins. MRV using the Valsalva maneuver allows assessment of reflux to the great saphenous vein.

A case of cold urticaria showing metachromasia in skin biopsy / 천식및알레르기

The patient was a 24-year-old male who complained of urticaria upon exposure to cold air and after showering in cold water. Allergic skin tests were positive for cockroach. To determine whether he had cold urticaria, we performed an ice cube test. The patient complained of pruritus, erythema, and wheals appeared at 10min. Skin biopsy specimens collected 10 minutes after ice-cube test showed perivascular mononuclear cell infiltration and edema in hematoxylin and eosin stains, and metachromatic cell and degranulation in toluidine blue stain.

A case of metastatic large cell carcinoma of the duodenum from the lung / 대한내과학회지

It is very rare for the primary lung cancer to metastasize to gastrointestinal tract, which has poor prognosis. A 72-year-old man admitted with dyspnea and a mass lesion in the left lower lobe on chest roentgenogram and chest computed tomogram(CT). Large cell carcinoma of the lung was diagnosed by percutaneous needle biopsy. Also gastroduodenoscopy was conducted for evaluation of gastrointestinal symptoms, such as indigestion and epigastric discomfort. Large cell carcinoma of duodenum was diagnosed by biopsy of duodenal polyp, which was considered to be metastasized from the primary lung cancer. Palliative radiation therapy was performed, but he died 2 months after diagnosis. We report a rare case of large cell carcinoma of the lung with metastasis to uodenum.

H rthle Cell Neoplasm of the Thyroid Gland

PURPOSE: H rthle cell neoplasm of the thyroid gland is a rare disease. The reported cases in Korea are not so many; thus, there has been a lack of common therapeutic and prognostic guidance. METHODS: The cases of 15 patients with a H rthle cell neoplasm of the thyroid gland, hospitalized at Seoul National University Hospital from Nov. 1981 to Feb. 1998, were retrospectively reviewed. RESULTS: There were 4 males and 11 females. The ages varied from 23 to 69 years old (mean: 46.3 years old). Among them, 13 had neck masses with a mean size of 3.3 cm (1.2-6.0 cm), and the mean duration of the symptom was 4 years (5 months-8 years). Of the other two, one had laryngeal discomfort for 2 months, and the other one was diagnosed through a fine needle aspiration follow-up. One of the 15 patients had hyperthyroidism whereas the others had euthyroidism. The thyroid scans for 10 of them showed cold nodules. The operations consisted of a unilateral lobectomy in 2 cases, a unilateral lobectomy and isth mectomy in 11 cases, a unilateral lobectomy, isthmectomy and contralateral partial lobectomy in 1 case, and a total thyroidectomy and neck lymph node dissection in the 1 case that was combined with a papillary carcinoma. Thirteen patients (86.7%) had a H rthle cell adenoma, and two of them (13.3%) had a H rthle cell carcinoma. The mean duration of follow-up was 33 months (range 1 month-12 years), and no recurrence or death occurred during the follow-up period. CONCLUSIONS: The incidence of H rthle cell neoplasms is higher in women and the sex ratio is 1:2.8. The incidence of H rthle cell carcinomas among H rthle cell neoplasms is 13.3% (2/15). We found no specific clinical features for differentiating a H rthle cell adenoma from a H rthle cell carcinoma and no factors for adequate operative methods and prognosis due to the rarity of the condition and the short duration of the follow-up. Because of the low incidence of H rthle cell neoplasms and our limited experience, not only co-research of centers but also pathologic research is needed.

The Frequency of Stress Urinary Incontinence in Primiparas and Relationship / 대한비뇨기과학회지

No abstract available.

Donor Leukocyte Infusion as Treatment for Relapsed Leukemia after Allogeneic Bone Marrow Transplantation : Graft-versus-Leukemia Effect / 대한혈액학회지

BACKGROUND: Donor leukocyte infusion (DLI) is an effective therapy for patients who relapse with leukemia after allogeneic bone marrow transplantation (BMT). This is due to the fact that the immune reactivity of infused allogeneic lymphocytes on relapsed leukemia cells plays a major role in the control of leukemia. However, severe graft-versus-host disease (GVHD) and pancytopenia compromise the success of this treatment in a substantial number of patients. METHODS: To evaluate the effect of DLI, we surveyed 6 BMT centers regarding their use of DLI for relapsed leukemia after BMT. Detailed forms were used to gather data regarding the original BMT, relapse, response to DLI, complication and survival. Reports of 11 patients were consequently available for analysis. RESULTS: Five (83.3%) of 6 patients with chronic myeloid leukemia (CML) achieved complete remission (CR) [time-to-CR; 116 (27~180) days after DLI], and currently 4 are alive in CR (49~436 days). Five patients (83.3%) developed GVHD, and 2 developed pancytopenia which was related to DLI. In acute leukemia, all patients received salvage chemotherapy prior to DLI. Only 1 of 3 patients with acute lymphoblastic leukemia (ALL) who had early relapse achieved CR, but durable remission was not yet confirmed (62+ days). Both 2 patients with acute myeloid leukemia (AML) achieved CR, and their CR durations were 242+ and 326 days after DLI, respectively. CONCLUSION: This study demonstrates that DLI can exert considerable effects against myeloid forms of leukemia, especially in CML. Further investigations of separating GVHD from the graft- versus-leukemia effect and finding more effective anti-leukemia approaches on acute leukemiaare necessary to improve the current DLI limitations.

Clinical Analysis of Malignant Pheochromocytoma / 대한암학회지

PURPOSE: There are no specific clinical and histopathologic characteristics of malignant pheochromocytoma and the optimal treatment modality has not been established yet. We analyzed the clinical and histopathologic features of malignant pheochromocytoma and treatment results. MATERIALS AND METHODS: We reviewed the clinical records of 10 patients with malignant pheochromocytoma diagnosed at Seoul National University Hospital from March 1987 to June 1998. RESULTS: Nine of 10 (90%) patients had functional tumors. The biochemical laboratory findings showed elevated 24-hour urine VMA level in nine patients available. The median size of the tumors was 11x11 cm. Six of 10 (60%) patients were initially diagnosed as malignant tumors because of direct invasions to adjacent tissues or distant metastases. On the other hand, remaining 4 patients were initially diagnosed as benign, but the distant metastases developed metachronously after resection of the primary lesion. The median duration between the initial operation and the detection of metastases was 57 months (range: 47~72 months) in these patients. The liver was the most common site of metastases (60%). With regards to the histopathological features, most of the tumors (87.5%) showed capsulation, necrosis and hemorrhage. The findings of lymphatic invasion, angio-invasion, and mitosis were found in 62.5% of the cases. All but 2 patients were initially treated with radical operation for the primary lesions. The disease recurrences or metastases occurred in 7 out of 10 patients. Of these, 4 patients were treated with chemotherapy or interferon- a after recurrences. Overall, the median survival for all patients was 82 months (range: 37~143 months). Two patients is alive and only one patient is alive without recurrence. CONCLUSION: The careful follow-up for at least 5 years and the aggressive multi-disciplinary therapy may be needed for the diagnosis and the management of malignant pheochromocytoma.

Development of Internet-based Medical Educational Program / 한국의학교육

Current medicine is a living science which is developing rapidly. It seems that coming up with the rapid development of medicine by the conventional educational system has some limitation, since the development is too rapid. Development of internet-based medical educational program(IMEP) would be a kind of solution. To overcome the limitation, we developed an IMEP which could be used either on the File Transfer Protocol(FTP) or World Wide Web(WWW), and tested whether it would meet the requirements of our purpose. The IMEP of ours functioned satisfactorily. IMEP for WWW was accessed by far more frequently than IMEP for FTP by the visitors. Frame-typed HTML files were displayed 2 times faster than plain HTML files. HTML files which hid the graphic data behind were displayed more quickly than conventional HTML files. CGI programs were considered to be necessary tools for bidirectional communications between the host and clients on the IMEP. A small PC server worked properly as well as a large server when the access was confined to a small number of visitors. We concluded that IMEP was an excellent adjuvant method of education to make up the gap between the conventional educational system and the rapid development of medicine.

The Diagnostic Accuracies of Fine Needle Aspiration Biopsy, Mammography and Ultrasonography in Palpable Breast Mass

BACKGROUND: Although an increasing number of breast abnormalities are detected by screening mammography, most breast cancers are presented as a palpable mass. Cytologic specimens are frequently diagnostic and may be easier to obtain. This study was done to compare the diagnostic accuracies of clinical breast exam, fine needle aspiration biopsy (FNAB), mammography and ultrasonography, and to establish the algorithm to manage the patients based on the results of FNAB. METHODS: From Jan. 1992 to Dec. 1997, one hundred and twenty-seven women out of 470 patients with a clinically palpable mass underwent concurrent FNAB, mammography, and ultrasonography. All patients ultimately had histologic confirmation by surgical biopsy. RESULTS: The sensitivity and the specificity of the tests were as follows: 79.2% and 74.4%, respectively, for clinical breast exam; 62.2% and 98.6%, for mammography; 55.8% and 93.3% for ultrasonography; and 66.7% and 100% for FNAB. Of note, the accuracy of the FNAB was significantly higher for lesions 2 cm or larger than for lesions smaller than 2 cm (p=0.034). All patients who were positive for malignancy on FNAB (n=20) presented with breast cancer. Among the 16 patients with suspicious results on FNAB and breast cancer on surgical biopsy, 3 had normal findings on mammography and ultrasonography. In the cases of negative findings for malignancy in three tests (n=55), no breast cancer was found on the final surgical specimen. CONCLUSION: It is recommended that FNAB must be performed on all palpable masses and that when the FNAB is postive for cancer, definitive surgery be performed with intraoperative frozen biopsy. Patients in whom mammography, ultrasonography and FNAB were negative for malignancy can be observed without the need for an open biopsy. Additionally, (1) when the results of FNAB are suspicious or (2) when the mammagraphy and ultrasonography results are suspicious even though the FNAB results are negative for malignancy, an open biopsy is required to exclude the possibility of the breast cancer.

Asymptomatic Breast Cancer

BACKGROUND: With no current method of prevention available, early detection of breast cancer by regular self and clinical examination in conjunction with screening mammography is emphasized. The rate of asymptomatic breast cancer detection has been increased due to the ability of mammography. METHODS: To address questions about the biology and clinical manifestation of mammographically detected breast cancer, a retrospective analysis was performed to the 31 cases of asymptomatic breast cancer treated from Jan. 1989 to Dec. 1996 at Department of Surgery, Seoul National University Hospital. RESULTS: The mean age was 50.0 with ranges from 27 to 80. The peak age was 5th decade. The most common mammographic findings of asymptomatic breast cancer was microcalcification (22 cases, 71.1%). Eighteen patients underwent modified radical mastectomy (58.1%): simple mastectomy in 4 cases (12.9%), and breast conserving surgery in 9 cases (29.0%). The histologic types were as follows: infiltrating ductal carcinoma in 17 cases (64.5%), microinvasive carcinoma in 3 cases (9.6%) and ductal carcinoma in situ in 9 cases (29.0%). Twenty one patients showed smaller than 1 cm in tumor size. Only 3 cases of invasive ductal carcinomas had axillary nodal metastasis. All cases except four cases demonstrated stage 0 (29.1%) and stage I (54.8%) according to the AJCC classification: whereas the rate of stage 0 and I in symptomatic patients during same study period was 4.1% and 19.6% respectively. CONCLUSIONS: The result of our study indicate that several benefits of mammographic screening are likely the result of detection of invasive carcinoma at an early stage and detection of noninvasive carcinoma that may later develop into or mark increased risk of invasive carcinoma. A prospective and systematic approach for evaluating efficiency of screening mammography would be necessary in Korea.