Outcomes of sonography-based management of breast cysts

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1 The American Journal of Surgery 188 (2004) Scientific paper Outcomes of sonography-based management of breast cysts Hernan I. Vargas, M.D.*, M. Perla Vargas, M.D., Katherine D. Gonzalez, R.N., Kamal Eldrageely, M.D., Iraj Khalkhali, M.D. Harbor University of California Los Angeles Medical Center, 1000 W. Carson St., Box 25, Torrance, CA 90509, USA Manuscript received May 19, 2004; revised manuscript June 6, 2004 Presented at the Fifth Annual Meeting of the American Society of Breast Surgeons, March 31 April 4, 2004, Las Vegas, Nevada Abstract Background: Ultrasound is commonly used during diagnosis of breast lesions. Our purpose was to study the role of sonography for risk stratification of malignancy in the diagnosis and management of palpable breast cysts. Methods: This was a cohort study of 176 patients with palpable breast cysts. Sonographic findings were correlated with clinical and pathologic outcomes. Results: Mean cyst size was cm. Cysts were simple, complex and probably benign, and complex and suspicious for neoplasm in 82.25%, 10.25% and 7.5% of patients, respectively. Thick cyst wall (P ), mural tumor (P ), eccentric mass (P 0.034), and internal septae (P 0.031) were predictive of neoplasm. Of cysts 3 cm, 33% were cancerous (P ). After 378 days of follow-up, 26 % of cysts had recurred. Recurrence was more frequent in patients with bilateral or multiple cysts (P 0.004). Conclusions: Sonography is useful in risk stratification of malignancy in breast cysts. There is a high risk of recurrence after cyst aspiration Excerpta Medica, Inc. All rights reserved. Keywords: Breast cancer; Breast cyst; Breast sonography; Diagnosis; Outcomes Breast cysts are presumed lobular lesions in which individual acini or terminal ducts dilate, twist, and fold to produce a loculation that enlarges as a cyst [1]. Haagensen estimated that 7% of women develop palpable breast cysts in the Western world [2,3]. Although cysts are generally regarded as benign, the incidence of cancer ranges from 0.1% to 1.2% [4 6], thus careful analysis of each individual case is indicated. Breast sonography was initially introduced as a means of differentiating cysts from solid lesions. Hilton et al [7] reported that the presence of simple cysts eliminates the need for further diagnostic measures such as aspiration biopsy or follow-up. Simple cysts are anechoic, well circumscribed, and have an imperceptible wall and posterior acoustic enhancement [8]. However, some breast cysts do not fulfill all criteria for simple cysts and are often referred to as complex cysts. Recommendations for the management of complex cysts * Corresponding author. Tel.: ; fax: address: hvargas@ucla.edu range from close follow-up to aspiration cytology or biopsy. The purpose of this study was to evaluate the use of breast sonography as a tool for risk stratification and biopsy guidance in the diagnosis and management of palpable cystic lesions of the breast. Patients and Methods This was a cohort study of patients presenting with palpable breast masses between June 2001 and July 2003 at Harbor University of California Medical Center in Torrance, California. Cases were selected from a prospective database of 1,931 individuals who underwent breast sonography. The criteria for inclusion were palpable breast lump and sonographic characteristics of a cyst (anechoic or low echo levels and posterior enhancement). Patients with solid lesions and/or previous biopsy were excluded. Sonographic examination of the breast (high-resolution 7.5- to 13-MHz transducer; Sonoline; Siemens, Issaquah, Washington) was limited to the area of palpable or mammographic abnormality. Sonographic information regarding the presence of internal echoes, characteristics of the cyst /04/$ see front matter 2004 Excerpta Medica, Inc. All rights reserved. doi: /j.amjsurg

2 444 H.I. Vargas et al. / The American Journal of Surgery 188 (2004) Fig. 1. (A) Simple cyst. (B) Complex and probably benign cyst: low level internal echoes and thin septae (white arrowhead). (C) Complex and suspicious cyst: thick cyst wall (white arrowhead). (D) Complex and suspicious cyst: mural tumor (white arrowhead). wall, internal septae or presence of mural or eccentric mass, and an overall clinicoradiologic impression were recorded. Lesions were classified as simple cysts (anechoic, imperceptible wall, posterior acoustic enhancement, completely aspirated [Fig. 1A]); complex and probably benign cysts (hypoechoic, thin internal septae, completely aspirated [Fig. 1B]); or complex cysts suspicious for neoplasm (thick wall [Fig. 1C]), mural tumor [Fig. 1D], eccentric mass, bloody fluid aspirate. Our clinical practice is to aspirate all palpable cysts because they are all regarded as symptomatic. Tissue diagnosis was obtained (1) in cysts with thick walls or septae, mural tumor, or associated mass; (2) in cysts with a residual solid component after sonography-guided aspiration; and (3) in cysts with bloody fluid. Patients in whom cyst aspiration lead to complete resolution of the palpable and sonographically visible abnormality were examined 6 weeks after aspiration. Long-term follow-up was obtained by review of the patient s medical record, correspondence, and telephone follow-up. Sonographic characteristics of the lesions were correlated with clinical and pathologic outcomes. Chi-square or Fisher s Exact test were used to compare categorical differences between groups. Mann- Whitney U test was used for analysis of continuous variables. P 0.05 was regarded as significant. Results A total of 176 patients met inclusion and exclusion criteria during the study period. Patient s demographic and historic information is listed in Table 1. Mean cyst size was cm. Diagnostic mammography was performed in 153 patients, 12 of whom had category 4 or 5 lesions. Sonographic characteristics are listed in Table 2. Palpable lumps were sonographically simple cysts in 145 (82.25%), complex and probably benign in 18 (10.25%), and complex and suspicious for neoplasm in 13 (7.5%) patients. Clinical outcomes, pathologic diagnosis, and recurrence rates are listed in Table 3.

3 H.I. Vargas et al. / The American Journal of Surgery 188 (2004) Table 1 Demographic, historical and exam characteristics Demographic characteristics n 176 Age (years) Mean SD Range Menopausal status No. premenopausal (%) No. postmenopausal (%) Previous history Hormone replacement therapy No. population (%) No. postmenopausal patients (%) History of cysts No. yes (%) No. no (%) Symptoms/Examination Palpable lump No. yes (%) No. 1 breast (%) No. Both breasts (%) No. single lump (%) No. multiple lumps (%) Breast pain No. yes (%) No. no (%) Six patients had cyst-associated neoplasm; 2 had intracystic papilloma; 1 had an intracystic papillary carcinoma; and 3 had infiltrating ductal carcinoma. Sonographic criteria such as thick cyst wall (P ) and mural tumor (P ) were highly predictive of cyst-associated neoplasm. The presence of an eccentric mass (P 0.034) and internal septae (P 0.031) were moderately predictive of neoplasm, but hypoechoic cysts were not associated with a higher risk (P 0.216). Neoplasm occurred more commonly in larger cysts (P 0.003). The incidence of cancer was zero in cysts 3 cm and 33% in cysts 3cm(P ). No additional cases of cyst-associated neoplasm have occurred during follow-up. All complex cysts 5 cm were cancer. Table 2 Sonographic characteristics Echogenicity (%) Anechoic 86.4 Hypoechoic 13.6 Echogenic 0 Wall thickness (%) Imperceptible 93.7 Thick 6.3 Internal septae (%) No 94.9 Yes 5.1 Mural tumor (%) No 96.6 Yes 3.4 Eccentric mass (%) No 99.5 Yes 0.5 Follow-up was available in 74 % of cases. Median follow-up was 378 days. Cyst recurrence occurred in 26.7% of all cases. Recurrence was more frequent in patients with a previous history of cysts (P 0.001) and in patients with bilateral (56%) or multiple cysts (33%) relative to single cysts (20%) (P 0.004). Patient s age, menopause status, or hormone replacement treatment (P 0.39) did not influence the incidence of cyst recurrence. Sonographic criteria were not predictive of recurrence (P 0.71). Comments Contemporary diagnosis of patients presenting with a palpable breast mass is based on the complimentary aspects of triple assessment. Triple assessment combines the results of clinical examination, breast imaging, and needle biopsy. Gross or palpable breast cysts are thought to be aberrations of the normal process of involution and not a disease [9]. The reported presence of malignancy in cystic lesions of the breast is low and ranges from 0.2% to 1.3% [4 6]. In our series, the incidence of malignancy was slightly higher than reported by others. Malignancy accounted for 2.2% of our cases, underscoring the importance of thorough evaluation of patients with palpable breast cysts. Breast sonography for the diagnosis of cysts is well documented in the literature [7,10]. Although simple cysts are recognized as benign, the definition of complex cysts is more elusive, and this group represents a heterogeneous category. We used breast sonography as a guide for diagnosis and management and as a means of stratification of patients according to risk for neoplasm. Our experience validates the proposed algorithm depicted in Fig. 2. Explicit sonographic criteria such as the presence of a mural tumor, thick cyst wall, or eccentric mass are factors that carry a high incidence of malignancy and mandate a tissue diagnosis. We also recommend tissue diagnosis if the aspirate is bloody or if there is a residual solid component after cyst aspiration. Finally, complex cysts 3 cm present a high risk of malignancy and must be biopsied. In contrast, simple cysts characterized by anechoic lesions with imperceptible wall and posterior acoustic enhancement can be regarded as benign and require no further assessment. The lesion may be aspirated to provide symptomatic relief and to facilitate patient self-examination. Under these circumstances, nonbloody cyst fluid may be discarded because the diagnostic yield is extremely low, and often the presence of atypical cells that have an unknown significance causes undue concern in the patient and physician [11]. Follow-up of these patients is not necessary, and age-appropriate annual screening is sufficient. Complex cysts characterized by the presence of lowlevel internal echoes and thin septae are generally benign. Low-level internal echoes may be the result of debris within the cyst fluid [12]. Deep-seated lesions in the breast or cysts 5 mm may have internal echoes based on the physical

4 446 H.I. Vargas et al. / The American Journal of Surgery 188 (2004) Table 3 Clinical outcomes, pathologic diagnosis, and recurrence rates Cyst Type n (%) Aspiration outcome Tissue diagnosis n Follow-up No. completely aspirated (%) No. Incompletely aspirated residual solid component (%) Median (d) Cyst recurrence (%) Simple cyst 145 (82) 143 (98.5) 2 (1.5) Inflammatory changes Fibrocystic changes 1 Complex cyst: 18 (10) 16 (89) 2 (11) Inflammatory changes probably benign Complex cyst: 13 (8) N/A N/A Infiltrating ductal cancer * suspicious for Papillary cancer 1 neoplasm Intracystic papilloma 2 Inflammatory changes 3 Fibrocystic changes 1 * Cyst recurrence rate in the three cysts that were not biopsied. Fig. 2. Breast cyst management algorithm.

5 H.I. Vargas et al. / The American Journal of Surgery 188 (2004) phenomenon of reverberation. Decrease in the dynamic range and the use of tissue harmonics have been recommended to eliminate this artifact [13,14]. Thin internal septae often represent a fold of a cyst or a wall separating adjoining cysts. We have not observed any association with malignancy. Cysts recurrence is a common event. This is likely related to the poorly understood pathogenesis of cyst formation. Patients with a history of cysts or patients with multiple cysts have a significantly higher incidence of recurrence, whereas patients with single cysts have a lower recurrence rate. Dixon [3] has hypothesized that there are 2 populations of breast cysts. Patients with recurrent or multiple cysts have apocrine lining of the cyst wall, and this may be responsible for the higher risk of recurrence. Patients with single cysts have cysts with flattened epithelium, which carry a low risk of recurrence. In summary, cystic lesions of the breast are common. Breast sonography is a useful tool for risk stratification of malignancy in patients with palpable cysts. Sonography-guided cyst aspiration is highly successful in achieving resolution of simple cysts; however, there is a high recurrence rate. References [1] Wellings SR, Jensen HM, Marcum RG. An atlas of subgross pathology of the human breast with special reference to possible precancerous lesions. J Natl Cancer Inst 1975;55: [2] Haagensen CD. Diseases of the breast. 2nd ed. Philadelphia, PA: Saunders; [3] Dixon JM, McDonald C, Elton RA, Miller WR on behalf of the Edinburg Breast Group. Risk of breast cancer in women with palpable breast cysts: a prospective study. Lancet 1999;353: [4] Abramson DJ. A clinical evaluation of aspiration of cysts of the breast. Surg Gynecol Obstet 1974;139: [5] Rosemond GP, Maier WP, Brobyn TJ. Needle aspiration of breast cysts. Surg Gynecol Obstet 1969;128: [6] Gatchell FG, Dockerty MB, Clagett OT. Intracystic carcinoma of the breast. Surg Gynecol Obstet 1958;106: [7] Hilton SW, Leopold GR, Olson LK, Wilson SA. Real-time breast sonography: application in 300 consecutive patients. Am J Radiol 1986;165: [8] Venta LA, Kim JP, Pelloski CE, Morrow M. Management of complex breast cysts. Am J Roentgenol 1999;173: [9] Hughes LE, Bundred NJ. Breast macrocysts. World J Surg 1989;13: [10] Nightingale KR, Kornguth PJ, Walker WF, et al. A novel ultrasonic technique for differentiating cysts from solid lesions: preliminary results in the breast. Ultrasound Med Biol 1995;21: [11] Hindle WH, Arias RD, Florentine B, Whang J. Lack of utility in clinical practice of cytologic examination of nonbloody cyst fluid from palpable breast cysts. Am J Obstet Gynecol 2000;6: [12] Stavros AT, Thickman D, Rapp CL, et al. Solid breast nodules: use of sonography to distinguish between benign and malignant lesions. Radiology 1995;196: [13] Berg A, Campassi C, Ioffe O. Cystic lesions of the breast: sonographicpathologic correlation. Radiology 2003;227: [14] Sklair-Levy M, Muradali D, Kulkarni S: Linear transducer harmonic imaging: improved characterization of breast cysts compared to conventional sonography (abstr). Am J Roentgenol 2001;176(suppl):6 7.