Invasive Papillary Carcinoma of the Breast: Clinicopathological Features and Hormone Receptor Profile

Atif A Hashmi; Shahzeb Munawar; Naumana Rehman; Omer Ahmed; Sabeeh Islam; Ishaq Azeem Asghar; Anoshia Afzal; Muhammad Irfan; Farozaan Shamail; Syed J Ali

doi:10.7759/cureus.13480

Invasive Papillary Carcinoma of the Breast: Clinicopathological Features and Hormone Receptor Profile

Cureus. 2021 Feb 22;13(2):e13480. doi: 10.7759/cureus.13480.

Authors

Atif A Hashmi¹, Shahzeb Munawar², Naumana Rehman³, Omer Ahmed⁴, Sabeeh Islam^{5

6}, Ishaq Azeem Asghar⁷, Anoshia Afzal⁸, Muhammad Irfan⁹, Farozaan Shamail¹⁰, Syed J Ali¹¹

Affiliations

¹ Pathology, Liaquat National Hospital and Medical College, Karachi, PAK.
² Internal Medicine, Liaquat College of Medicine and Dentistry, Karachi, PAK.
³ Pathology, Khyber Medical University, Peshawar, PAK.
⁴ Internal Medicine, Liaquat National Hospital and Medical College, Karachi, PAK.
⁵ Internal Medicine, St. Vincent Health Center, Buffalo, USA.
⁶ Internal Medicine, Faisalabad Medical University, Faisalabad, PAK.
⁷ Pathology, Ascension St. John Hospital, Detroit, USA.
⁸ Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, USA.
⁹ Statistics, Liaquat National Hospital and Medical College, Karachi, PAK.
¹⁰ Pathology, Ziauddin University, Karachi, PAK.
¹¹ Pathology, Dow University of Health Sciences, Karachi, PAK.

Abstract

Introduction Papillary neoplasms are a heterogeneous group of breast lesions, ranging from benign to in situ and invasive malignant tumors. The term invasive papillary carcinoma (IPC) is reserved for rare invasive breast tumors showing greater than 90% papillary morphology. The clinical, epidemiological and pathological characteristics of IPC are not widely described in the existing literature; therefore, in this study, we evaluated the clinicopathological features and biomarker profile of IPC and compared it with invasive ductal carcinoma (IDC) diagnosed in the same study duration. Methods A retrospective study was conducted in the Department of Histopathology, Liaquat National Hospital and Medical College, from January 2013 to December 2020. During the study period, 44 cases of IPC and 1,268 cases of IDC were diagnosed. Slides and blocks of all cases were retrieved and histopathological diagnosis was reviewed. Estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2/neu), and Ki67 immunohistochemical (IHC) stains were applied on representative tissue blocks. Results The mean age of the patients with IPC was 58.77±8.38 years, and the mean Ki67 index was 19.95±21.12%. The mean tumor size was 32.41±17.39 mm, and most tumors (59.1%) were tumor (T)-stage T2. Axillary metastasis was present in 13.6% cases, and 86.4% cases had nodal (N)-stage N0. ER and PR expression was noted in 72.7% cases, and HER2/neu positivity was seen in 13.6% cases. IPC cases had a higher mean age than IDC. Conversely, IPC had a lower mean Ki67 index than IDC. Similarly, IPC cases were found to have a lower frequency of axillary metastasis than IDC. IPC was noted to have a lower frequency of T3-stage and lymphovascular invasion than IDC. A higher expression of PR and lower frequency of HER2/neu expression was noted in IPC than IDC. Conclusion IPC is a rare malignant papillary breast tumor with a wide differential diagnosis and therefore poses a significant diagnostic challenge. We found that IPC had a favorable pathological profile than IDC, in terms of T-stage, Ki67 index, axillary metastasis, PR and HER2/neu expression.

Keywords: breast cancer; estrogen receptor; human epidermal growth factor receptor 2; invasive ductal carcinoma; invasive papillary carcinoma; ki67; papillary lesions; progesterone receptor.