Ultrasound-Guided Radiofrequency Ablation for Pseudoangiomatous Stromal Hyperplasia: A Rare Benign Breast Lesion

Abstract

Pseudoangiomatous stromal hyperplasia (PASH) is a rare benign breast condition characterized by stromal proliferation that can mimic other breast pathologies, including malignant lesions and benign lesions like fibroadenomas and phyllodes tumors. Surgical excision has traditionally been preferred treatment for symptomatic cases, but minimally invasive techniques, such as ultrasound-guided radiofrequency ablation (RFA), are emerging as promising alternatives. We report a case of a 21-year-old young female diagnosed with PASH who was successfully treated with RFA, achieving complete resolution of symptoms and preservation of breast tissue integrity.

 

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Keywords

pseudoangiomatous stromal hyperplasia - RFA - benign breast disease

Introduction

Pseudoangiomatous stromal hyperplasia (PASH) is a rare benign breast disease characterized by proliferation of stromal myofibroblasts, anastomosing slit-like pseudovascular spaces, which are either acellular or lined by slender spindle-shaped stromal cells.[1] PASH may present clinically as a palpable mass or as an asymptomatic detected mass, and some patients experience breast discomfort or anxiety due to rapid lesion growth.[2] Clinical and radiological findings of PASH may resemble those of other breast pathologies and all imaging modalities have no specific features to characterize PASH.[3] Traditional management of PASH includes follow up, needle biopsy, or surgical excision.[4] Minimally invasive methods are potential alternatives for the treatment of benign breast lesions. For example, percutaneous ablation and the Mammotome system, which has been already approved for removal of small fibroadenomas.[5] Minimally invasive techniques like radiofrequency ablation (RFA) offer a promising, tissue-sparing approach with fewer complications. RFA is already established in both benign and malignant breast lesions.[6] [7] This report presents a case of symptomatic PASH successfully treated with ultrasound (USG)-guided RFA, demonstrating the effectiveness of this approach.

 

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Case Report

A 21 -year-old female presented with a palpable, painless mass in her left breast, which was insidious in onset and gradually progressive. There was mild discomfort for the past 2 months without fever or discharge from the nipple. There was no significant family history. On clinical examination, a palpable lump of 5 × 4 cm was observed in the left breast involving the central and lower outer quadrant. The lump was firm in consistency and not fixed to the skin or underlying muscle. No nipple retraction, peau d'orange appearance, and hyperpigmentation of the breast skin was noted on clinical examination. Preablation USG image revealed an irregular hypoechoic mass (16 × 21 × 22 mm) with lobulated margin at 4 to 5 o'clock of left breast and posterior acoustic shadowing ([Fig. 1A] and [B]). Color Doppler study revealed a few penetrating and radial internal vessels within the lesion, suggesting internal vascularity ([Fig. 1C]). Core needle biopsy of the lesion revealed dense collagenous stroma displaying few slit-like spaces, lined by flattened spindle cells and few benign glands lined by inner ductal and outer myoepithelial cell layer, consistent with PASH ([Fig. 1D]). Lesion size was stable without any significant changes during follow-up for more than 12 months. Patient was offered both surgical and minimally invasive procedure (RFA). Due to the patient's preference to avoid surgery and absence of malignant features, USG-guided RFA was performed. The patient tolerated the procedure well, with no complications. The procedure was performed under sedation and USG guidance.

Fig. 1 A 21-year-old female with a left breast palpable mass. Histopathological examination revealed pseudoangiomatous stromal hyperplasia (PASH), preablation imaging. (A and B) Ultrasound (USG) grayscale image: An irregular hypoechoic mass (*) with lobulated margins at 4 to 5 o'clock of the left breast with posterior acoustic shadowing, measures 16 × 21 × 22 mm. (C) Color Doppler image: Few penetrating and radial internal vessels within the lesion, suggesting internal vascularity. (D) Photomicrograph (40× magnification; hematoxylin and eosin stain) showing dense collagenous stroma displaying few slit-like spaces, lined by flattened spindle cells and few benign glands lined by inner ductal and outer myoepithelial cell layer consistent with pseudoangiomatous stroma hyperplasia.

Anesthesia: The RFA procedure was performed in the interventional radiology room under continuous monitoring of heart rate, oxygen saturation, respiratory rate, and blood pressure in the presence of an anesthesia team. Oxygen was given at the rate of 2 L/min. The patient initially received satisfactory local anesthesia with 5 mL of diluted 2% lidocaine to facilitate the introduction of the RFA needle. After the needle insertion, the patient was sedated by using a combination of 2 mg midazolam (0.05 mg/kg), 1 μ/kg fentanyl (0.5 mcg/kg), and 0.5 mg/kg intravenous bolus with 0.1 mg/kg/min infusion of propofol intravenously. The steps of RFA procedure: USG-guided RFA was performed using the RF 3000 system (Boston Scientific) equipped with a 14-gauge expandable needle electrode. Lesion localization, needle trajectory guidance, and procedural planning were facilitated by the Aixplorer USG system (SuperSonic Imagine, Aix-en-Provence, France) using a linear-array transducer (10–2 MHz).The patient was in supine position, with extended and fixed arms. After administration of a local anesthetic at the lesion site, hydrodissection was performed under USG guidance by injecting 0.9% normal saline between the chest wall, skin, and lesion ([Fig. 2A]). This created an isolation zone to prevent skin burns or necrosis during ablation. The RFA expandable needle electrode was placed at distal end of the lesion under USG guidance. The power was set up to 10 to 15 W, with center temperature up to 65 to 95°C. The impedance of ablation zone area slowly increased with more degree of ablation. The RFA analyzer had automatic stop once highest degree of impedance was reached, indicating complete ablation of the lesion. USG monitoring was applied during the procedure, and location of probe adjusted as needed. The gasification range covered the tumor mass completely. A single intravenous dose of paracetamol 1000 mg, diluted in 100 mL of 0.9% sodium chloride, was administered immediately after the procedure over an infusion. This was followed by oral nonsteroidal anti-inflammatory drug every 6 to 8 hours for 3 days to manage postprocedural pain. For antibiotic prophylaxis, a single intravenous dose of ceftriaxone 1 g was given 30 minutes before the procedure and continued for 24 hours (three times a day), followed by amoxicillin–clavulanate 625 mg orally, three times daily for 5 days to prevent infection. Local cold packs were applied for 5 to 6 hours after operation to minimize the heat of the operation area. Clinical examination of the breast after 24 hours of the procedure revealed a minimal scar at the procedure site, with no evidence of skin burn or bruising ([Fig. 2B]).

Fig. 2 Intraoperative and postprocedure image in the same patient shows: (A) Intraoperative ultrasound (USG) grayscale image with radiofrequency ablation (RFA) needle (arrowheads) in situ within lesion (*) and hydrodissection (arrows), to elevate lesion from the chest wall (curved arrow). (B) Postprocedure images of the patient showing a minimal scar at the procedure site, with no evidence of skin burn or bruising.

 

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Outcome and Follow-Up

One week postprocedure USG demonstrated an increase in echogenicity with minimal peripheral vascularity on color Doppler, indicating successful ablation ([Fig. 3A, B]) with tumor size of 16 × 17 × 18 mm.

Fig. 3 Postablation ultrasound (USG) image with color Doppler in the same patient shows: (A) Postablation USG grayscale image at 1 week shows a residual hypoechoic radiofrequency ablation (RFA) ablated lesion (*) of size 16 × 17 × 18 mm in the left breast. (B) Postablation color Doppler image at 1 week shows minimal vascularity within the lesion. (C) Postablation USG grayscale image at 3 months; RFA ablated lesion continued to shrink with a maximum size of 13 × 14 × 16 mm with increased areas of echogenicity (*) with surrounding hypoechoic capsule (arrowheads). (D) Postablation color Doppler image at 3-month interval shows perilesional minimal vascularity. No intralesional vascularity noted. (E) Postablation USG grayscale image at 6 months; RFA ablated lesion continued to shrink, measures 9 × 12 × 15 mm, and ablated tumor (*) with surrounding hypoechoic capsule (arrowheads). (F) Postablation color Doppler image at 6-month interval shows no intralesional or perilesional vascularity.

At 3- and 6-month follow-up, USG showed a significant reduction in lesion size measuring 13 × 14 × 16 mm at 3 months ([Fig. 2C, D]) and 9 × 12 × 15 mm at 6 months ([Fig. 2E, F]), with no evidence of recurrence. At 6 months, the lesion had completely regressed. The patient remained asymptomatic, and no complications were noted. Cosmetic outcomes were excellent, with no scarring or breast deformity.

 

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Discussion

The treatment of breast lesions should not only aim to ensure survival of the patients, but also aim to preserve their function, address cosmetic concerns, and be cognizant of the patients' mental status throughout the whole process, particularly for benign tumors.[5] Accordingly, since traditional surgical treatments are associated with greater trauma to the tissues that could lead to formation of scars and eventually undesirable cosmetic outcomes, attention has been drawn to minimally invasive methods for treatment of benign breast tumors such as USG-guided vacuum-assisted excision and USG-guided ablation.[8] Breast is the perfect organ for ablative treatments because it is superficial and only covered by the skin with no intervening structures, can be compressed in different directions to achieve the appropriate alignment of the instruments needed for ablation, and it can be monitored effectively by USG.[9] This case highlights potential of RFA as a viable alternative to surgical excision for symptomatic PASH. The benefits of RFA include minimal invasiveness, preservation of breast architecture, and reduced recovery time. While surgical excision remains the gold standard for large or recurrent lesions, RFA offers a promising option for select cases. USG imaging can be informative and cost-effective in pre- and postprocedure assessment of these tumors.

 

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Conclusion

RFA has significant advantages in treating benign breast lesions. RFA has proven effectiveness with a high absorption rate of ablated lesions. There is mild edema to surrounding tissues which maximally meets the esthetic demands of patients with insignificant recurrence. So, minimally invasive RFA techniques have great promise for effective, safe, and cosmetic treatment of benign breast lesions with insignificant recurrence. Further studies with larger cohorts and longer follow-up are needed to establish its role in clinical practice.

 

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Conflict of Interest

None declared.

Acknowledgment

None.

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Publication History

Article published online:
15 September 2025