Case report
Year : 2026 Month : April Volume : 15 Issue : 2 Page : PC07 - PC10 Full Version

Pseudoangiomatous Stromal Hyperplasia of the Breast Diagnosed on Excisional Biopsy: A Case Report
M Charika, R Padmavathi, N Lavanya, D Saranya
1. Postgraduate, Department of Pathology, Madras Medical College, Chennai, Tamil Nadu, India. 2. Professor, Department of Pathology, Madras Medical College, Chennai, Tamil Nadu, India. 3. Assistant Professor, Department of Pathology, Madras Medical College, Chennai, Tamil Nadu, India. 4. Assistant Professor, Department of Pathology, Madras Medical College, Chennai, Tamil Nadu, India.
 
Correspondence Address :
M Charika,
Madras Medical College and RGGGH, Evr Periyar Salai, Park Town,
Chennai-600003, Tamil Nadu, India.
E-mail: charikamacharla@gmail.com
 
ABSTRACT
: Pseudoangiomatous Stromal Hyperplasia (PASH) is a rare benign mesenchymal lesion of the breast. When PASH presents as a mass lesion, it is referred to as a PASH tumour, which is an uncommon manifestation. In the present case report, the authors describe a 34-year-old woman who presented with a painful lump in the left breast. Mammography revealed a well-defined dense lesion {BI-RADS IVa (Breast Imaging-Reporting and Data System Category 4a: Low Suspicion for Malignancy)} in the left breast, raising clinical and radiological suspicion of malignancy. A True-Cut (Tru-cut) biopsy was performed, and microscopic examination showed linear cores of breast parenchyma with a few terminal duct-lobular units. Malignancy was excluded using Immunohistochemistry (IHC), following which wide local excision was undertaken. The excised lesion was diagnosed as PASH. Histopathological examination showed a circumscribed lesion composed of terminal duct-lobular units with ducts and acini lined by inner luminal and outer myoepithelial cells. The stroma demonstrated anastomosing slit-like spaces lined by spindle to oval-shaped cells with bland nuclei, embedded within dense collagen. The spaces were empty. IHC revealed Cluster of Differentiation 34 (CD34) positivity in the spindle cells and Cluster of Differentiation 31 (CD31) negativity, helping to differentiate PASH from vasoformative lesions. The treatment of choice is complete surgical excision, as recurrence may occur following incomplete resection. There is no evidence of malignant transformation in PASH; therefore, accurate diagnosis is important to avoid overtreatment. PASH may occur in association with other breast lesions such as fibroadenoma, sclerosing lobular hyperplasia, and gynaecomastia; hence, careful evaluation for associated lesions with malignant potential is necessary. The present case is reported due to its rare presentation as a PASH tumour.
Keywords : Benign mesenchymal lesion, Myofibroblasts, Stromal proliferation
DOI and Others : DOI: 10.7860/NJLM/2026/82756.2971 Date of Submission: Sep 04, 2025 Date of Peer Review: Oct 08, 2025 Date of Acceptance: Dec 01, 2025 Date of Publishing: Apr 01, 2026 AUTHOR DECLARATION: • Financial or Other Competing Interests: None • Was informed consent obtained from the subjects involved in the study? Yes • For any images presented appropriate consent has been obtained from the subjects. Yes PLAGIARISM CHECKING METHODS: • Plagiarism X-checker: Oct 03, 2025 • Manual Googling: Nov 25, 2025 • iThenticate Software: Nov 29, 2025 (2%) ETYMOLOGY: Author Origin EMENDATIONS: 5
 
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