Ductal carcinoma in situ (DCIS) of the breast has been considered a relative rare form of breast cancer because its diagnosis was difficult but the widespread use of screening mammography has made it easy to detect breast disease and there has been a marked increase in the incidence of DCIS. But the exact diagnosis and treatment are controversial.

We reviewed the clinical record of 55 patients with DCIS treated at the Department of Surgery, Samsung Medical Center, between September 1994 and December 1997. If there was microinvasion noted, it was excluded from this study.

The incidence of DCIS was 11.5% of all breast cancer (55 out of 477) with increasing tendency from 1995 to 1997. DClS was most prevalent in woman who were in their fifth decades and the mean age was 47 years old. Chief complaints were palpable breast masses in 22 (40%), mammographic abnormalities in 21 (38%), abnormal nipple discharge in 7 (13%), and others in 5 cases (9%). The most common mammographic finding was microcalcifications in 41(84%), but the mass density and architectural distortion were also noted in small percentage. Diagnostic methods for preoperative pathology were fine needle aspiration (FNA) cytoloty in 15 (27%), localization and excisional biopsy in 16 (29.1%), excisional biopsy in 11 (20%), incisional biopsy in 5 (9%), stereotactic core biopsy in 3 (5.5%), US guided biopsy in 2 (3.6%) and ABBI (advanced breast biopsy instrumentation) biopsy in 3 (5.5%). If the chief complant was palpable masses, FNA was a diagnostic choice. On the other hand, if the problem was mammographic abnormalities, localization and excisional biopsy was preferred. The surgical procedures were modified radical mastectomy in 17 (31%), total mastectomy in 21 (38%) lumpectomy with axillary lymph node dissection in 7 (13%) and lumpectomy only in 10 (18%). If preoperative histology revealed the tumor of comedo type, mastectomy was preferred but in case of non-comedo type, conservative surgery was preferred, Conservative surgery was followed by radiation therapy. Cancers were subclassified according to their histologic subtypes in 51 cases and comedo was the most common type (42%). Prevalent size of the masses were less than 2 cm arid the biggest one was 9 cm. There were one case (2%) of lymph node metastasis. It was comedo type and the size of. cancer was 9 cm.

The widespread use of screening mammography and variable diagnostic method will increase the chance to detect the incidence of DCIS and conservative surgery will be performed more frequently in selected group of patients.