Abstract
Pediatric breast abscesses require timely infection control while minimizing injury to the developing breast. We report an 11-year-old pubertal girl with persistent left breast pain, swelling, and erythema after 7 days of oral antibiotic therapy. Physical examination revealed a fluctuant left breast mass and a tender contralateral cystic lesion. Inflammatory markers were elevated. Ultrasonography demonstrated a heterogeneous left-sided collection with peripheral vascularity, consistent with abscess formation, whereas the right breast showed a well-circumscribed anechoic cyst without inflammatory features. The antibiotic-refractory abscess was treated by incision and drainage, and the contralateral cyst was managed by needle aspiration. Culture of the purulent fluid yielded Staphylococcus epidermidis. Two-month ultrasonography showed marked lesion reduction. At 12-month clinical follow-up, no recurrence, nipple discharge, or obvious breast asymmetry was observed. The case shows how ultrasonography helped separate an abscess requiring drainage from a contralateral cyst that could be treated by aspiration.
Introduction
Management of breast lesions in children and adolescents differs from that in adults because the breast bud and surrounding tissue are still developing. Most pediatric breast masses are benign, but unnecessary intervention may cause scarring, cosmetic deformity, or impaired breast development [1–3]. Therefore, treatment decisions should be based on clinical severity and imaging findings rather than lesion size alone.
Ultrasonography is the preferred initial modality for pediatric breast evaluation. It can distinguish simple cystic lesions from abscesses and identify inflammatory features without radiation exposure [1, 2, 4]. This distinction is particularly important when cystic lesions with different inflammatory characteristics occur in the same patient. Bilateral cystic breast lesions with unilateral abscess formation have rarely been described [5, 6]. In such cases, management depends on whether each lesion shows clinical or sonographic evidence of infection. We describe an 11-year-old pubertal girl with an antibiotic-refractory left breast abscess and a contralateral cystic lesion without inflammatory features.
Case report
An otherwise healthy 11-year-old girl at Tanner stage B2 presented with severe bilateral breast pain, progressive swelling, and erythema of the left breast. Before admission, she had received a 7-day course of oral antibiotics at an outside institution, but her symptoms did not improve. She had no history of breast disease, trauma, systemic illness, or relevant family history.
Physical examination revealed a tender, erythematous, fluctuant mass measuring ~40 × 30 mm at the 2 o’clock position of the left breast. A mobile, tender cystic lesion measuring 35 × 15 mm was palpated at the 9 o’clock position of the right breast, without overlying skin changes. Laboratory testing showed leukocytosis, with a white blood cell count of 11.46 × 109/L and neutrophils of 72.8%. Outside records showed elevated C-reactive protein of 35 mg/L and mildly increased procalcitonin of 0.4 ng/ml.
Breast ultrasonography showed bilateral cystic lesions with different inflammatory features (Fig. 1). The left breast contained a 31 × 16 mm mixed echogenic collection with peripheral vascularity, consistent with abscess formation (Fig. 1B). The right breast contained a well-circumscribed 36 × 13 mm anechoic cyst without internal echoes or surrounding inflammatory change (Fig. 1A). Basal hormone testing showed luteinizing hormone of 21.27 IU/L, follicle-stimulating hormone of 4.73 IU/L, and estradiol of 170.2 pg/ml. These findings were compatible with pubertal development and did not affect management.
Ultrasonographic evaluation at presentation. (A) Right breast: A well-defined anechoic cyst measuring 36 × 13 mm without inflammatory features. (B) Left breast: A 31 × 16 mm mixed echogenic collection with peripheral vascularity consistent with abscess formation.
Because the left-sided abscess persisted despite oral antibiotic therapy and showed clinical fluctuation, incision and drainage was performed. Conservative observation was considered for the right breast cyst. However, aspiration was performed because the lesion was painful and relatively large, and the nature of the cystic fluid required confirmation in the setting of contralateral infection. Incision and drainage of the left breast yielded 15 ml of purulent fluid, whereas aspiration of the right breast cyst yielded 9 ml of clear cystic fluid. Culture of the purulent fluid yielded Staphylococcus epidermidis. Cytological examination of the clear right-sided fluid showed no malignant cells.
Susceptibility testing showed oxacillin resistance and a positive cefoxitin screen, with susceptibility to levofloxacin, vancomycin, linezolid, and trimethoprim–sulfamethoxazole. Fluoroquinolones were avoided because of pediatric safety concerns. Cefaclor was used as empirical postoperative oral therapy after adequate drainage.
Postoperative recovery was uneventful. At 2-month follow-up, ultrasonography showed interval reduction of both lesions (Fig. 2). At 12-month outpatient follow-up, physical examination showed no recurrent swelling, tenderness, erythema, nipple discharge, palpable residual mass, or obvious breast asymmetry. Repeat ultrasonography was not performed because the patient remained asymptomatic.
Follow-up ultrasonography at 2 months. (A) Right breast cyst showing significant reduction in size. (B) Left breast abscess cavity markedly decreased with near-complete resolution of inflammatory change.
Discussion
Pediatric breast abscesses should be managed according to symptom severity, abscess maturity, and response to conservative treatment [5, 7, 8]. Antibiotics may be sufficient for early infection, but drainage is usually required when a formed abscess persists or symptoms fail to improve [7, 8]. In this patient, the left-sided lesion remained painful after 7 days of oral antibiotic therapy. Physical examination showed fluctuation, and ultrasonography demonstrated a heterogeneous collection with peripheral vascularity. These findings supported incision and drainage rather than continued conservative treatment.
The contralateral lesion required a different approach. Ultrasonography showed a well-circumscribed anechoic cyst without surrounding inflammatory change. Conservative observation could have been considered because many pediatric cystic breast lesions are benign [1, 3, 4]. However, the right-sided lesion was painful and relatively large. Aspiration was therefore performed to relieve symptoms and confirm the nature of the cystic fluid. The clear aspirate and negative cytological findings supported a non-infected and non-malignant lesion. This result also supported lesion-specific management rather than bilateral surgical treatment.
The microbiological result should be interpreted cautiously. S. epidermidis may represent skin contamination, particularly in superficial specimens. In this case, the organism was isolated from purulent fluid obtained from a clinically and sonographically evident abscess. The culture result was therefore considered clinically relevant. Susceptibility testing suggested methicillin-resistant coagulase-negative staphylococci. Because the patient was a child, fluoroquinolones were avoided despite in vitro susceptibility. The favorable course after drainage suggests that adequate source control was the main therapeutic component, while postoperative oral antibiotics served as adjunctive therapy.
The endocrine findings were compatible with pubertal development, but this case cannot establish a causal relationship between hormone levels and cyst formation. Pubertal breast development may provide a physiological background for ductal and stromal changes, but clinical decision-making in this patient was based mainly on symptoms, physical examination, ultrasonographic findings, and fluid analysis. This report is limited by its single-patient design and the absence of repeat ultrasonography at 12 months. However, clinical follow-up showed no recurrence, palpable residual mass, nipple discharge, or obvious breast asymmetry. This case suggests that ultrasonography-guided, lesion-specific management may be useful when infected and non-infected cystic breast lesions coexist in a developing breast.
Author contributions
Y.Z. contributed to patient management, data collection, and manuscript drafting. Y.Z. contributed to clinical interpretation and manuscript revision. C.T. supervised the case management and critically revised the manuscript. All authors read and approved the final manuscript.
Conflicts of interest
The authors declare that they have no conflicts of interest.
Funding
This study received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Data availability
All relevant data are included in this article.
Ethical approval
Ethical approval was obtained from the Ethics Committee of the First Affiliated Hospital of Guangzhou University of Chinese Medicine (approval No. JY2025–165).
Consent
Written informed consent for publication of the clinical information and images was obtained from the patient’s legal guardians.
