Molecular subtyping of mammary Paget's disease using immunohistochemistry

Mammary Paget's Disease Mimicking Benign and Malignant Dermatological Conditions: Clinical Challenges and Diagnostic Considerations

Mammary Paget's disease (MPD) or Paget's disease of the breast is a rare dermatological malignancy of the nipple-areolar complex that manifests with a spectrum of symptoms spanning from itching and redness to more severe indications such as breast lump, nipple-areolar complex destruction, or nipple discharge. It is predominantly associated with an underlying ductal carcinoma in situ or invasive ductal carcinoma. MPD often masquerades as other benign and malignant dermatological conditions, including eczema, atopic dermatitis, psoriasis, and squamous and basal cell carcinomas, leading to delayed diagnosis and inappropriate treatment. Only one-third of the patients present with a palpable lump; therefore, advanced age with chronic and unilateral lesions should raise concern for MPD. Our review article presents case reports of MPD imitating other skin conditions and underscores the key findings of clinical features and diagnostic workup to help differentiate the condition. A literature review revealed that studies emphasize caution regarding the sole use of mammography and ultrasound in diagnosing MPD, particularly in cases lacking a palpable lump. This highlights the MRI as a superior and more accurate imaging tool. However, any suspicious lesion must be biopsied to allow histopathological and immunohistochemical examination, since there are some cases where MRI findings were negative in the presence of a biopsy-proven MPD. This highlights the need for clinicians to investigate any suspicious lesion of the nipple or breast using the complete triple assessment approach to exclude an underlying malignancy. It is imperative to establish therapeutic guidelines to approach any nipple lesion to minimize the risk of misdiagnosing any underlying cancer, which can be potentially fatal if left alone.

Clinicopathological features of mammary Paget’s disease: a single-center experience in Turkey

Background/aim

Paget’s disease (PD) of the breast is a very rare presentation of breast malignancy, accounting for 1%–3% of all primary breast tumors. We aimed to evaluate and compare the clinicopathological features and clinical outcome of PD accompanied by in situ carcinoma and invasive cancer.

Materials and methods

We used the archive of our pathology laboratory retrospectively for age, sex, history of surgery, histopathological findings, treatment modalities, and follow-up information. We used the Kaplan–Meier method for survival analysis.

Results

There were 46 female patients diagnosed with PD. In 39 (84.7%) patients, invasive carcinoma accompanied PD, while 7 (15.3%) patients had ductal carcinoma in situ. The median age at diagnosis was 53.5 years. The median follow-up period was 47 months. Of the 39 invasive carcinoma, 10 (25.6%) died during the follow-up period. Invasive ductal carcinoma group had a mean overall survival of rate of 57.8 ± 6.6 months. According to univariate analysis, only the tumor type was found to impact overall survival (p < 0.001).

Conclusions

The current study displayed the tumor type as the only parameter affecting overall survival in the invasive carcinoma group. Although it was not statistically significant, breast cancers accompanied by PD were found to be predominantly advanced stage tumors, high grade, hormone receptor negative, and HER2 positive.

Prevalence of mammary Paget's disease in urban China in 2016

No national data have been available on descriptive epidemiology of mammary Paget's disease (MPD) in China. This population-based study aimed to estimate the prevalence of MPD and its pattens by sex, age and area in China. We conducted a population-based study using data in 2016 from China's Urban Employee Basic Medical Insurance and Urban Resident Basic Medical Insurance, covering approximately 0.43 billion residents. MPD cases were identified based on the diagnostic names and codes in claim data. A total of 825 patients of confirmed diagnosis of MPD were found during the study period. The prevalence of MPD in 2016 was 0.42 per 100,000 population (95% CI 0.19 to 0.73), with marked female predominance. The prevalence rates peaked at 40-59 years and ≥ 80 years in females and males, respectively. The prevalence rates varied among different regions, ranging from 0.06 (95% CI 0.00 to 0.23) in Northeast China to 1.21 (95% CI 0.07 to 3.72) in Northwest China. MPD showed marked female predominance in China. Chinese female patients were much younger, with lower prevalence than that in the United States. Obvious sex difference in the age pattern of MPD prevalence was also observed in China.

Immunohistochemistry of mammary Paget's disease. Cytokeratin 7, GATA3, and HER2 are sensitive markers

OBJECTIVES

To investigate the expression of various immunohistochemical markers in Mammary Paget's disease (MPD) and MPD-associated breast carcinoma and to evaluate their value in establishing the diagnosis.

METHODS

This retrospective descriptive study was carried out at King Faisal Specialist Hospital and Research Center and King Khalid University Hospital, Riyadh, Saudi Arabia. All MPD cases reported between January 2010 and June 2016 were selected from the surgical pathology records.  Immunohistochemical staining was carried out for cytokeratin 7 (CK7), GATA-binding protein 3 (GATA3), human epidermal growth factor receptor 2 (HER2), and estrogen, and progesterone receptors. Results: Twenty-two cases of MPD and 20 cases of MPD-associated breast carcinoma were included. CK7 was positive in 95% (21/22) cases of MPD and in all (20/20) cases of associated breast carcinoma. Similarly, GATA3 was expressed in 95% cases of both MPD (21/22) and associated breast carcinoma (19/20). Human epidermal growth factor receptor 2 was also overexpressed in 90% cases of MPD (20/22) and associated breast carcinoma (18/20). Estrogen stained positive in 27% cases of MPD (6/22) and 30% of cases of associated breast carcinoma (6/20). Progesterone receptors was not positive in any case of MPD; however, it was seen positive in 25% cases of MPD-associated breast carcinoma (5/20).

CONCLUSIONS

CK7, GATA3, and HER2 are widely expressed in MPD and MPD-associated breast carcinoma. These markers can be used for the immunohistochemical confirmation of MPD including CK7-negative cases.

Establishment and characterization of breast cancer organoids from a patient with mammary Paget's disease

Background

Mammary Paget’s disease (MPD) is an uncommon cutaneous intraepithelial malignancy with ulceration of the nipple or areola. Its pathogenesis and genomic mutation remain largely unknown and no cell lines are established from primary tumors.

Methods

We collected surgical tumor specimens from a 65-year-old Chinese woman diagnosed with MPD and established patient-derived breast cancer (BC) organoids from MPD using organoid culture technology.

Results

We successfully propagated BC organoids from a patient with MPD for more than 6 months. The organoids were cultured for long-term expansion without any change in spherical organoid morphology. Besides, the spherical organoid morphology did not change when they underwent cryopreservation after resuscitation. The H&E staining and immunohistochemistry analyses showed the similar morphological and histological features of the organoids compared with their paired original BC tissues. The organoids retained positive expression of breast cancer biomarkers: estrogen receptor, progesterone receptor, antigen Ki-67 and negative expression of human epidermal growth factor receptor 2. We also showed that MPD organoids recapitulated the unique genomic landscape including copy number alterations, mutational load, mutational signatures and cancer gene mutations by whole genome sequencing. In situ senescence-associated acid beta galactosidase assay confirmed senescence phenomenon existed in the process of organoids culture and there was no significant difference in the proportion of senescent organoids after organoid passage and resuscitation.

Conclusions

Our results suggested that an effective platform for ex vivo BC organoids from MPD patients could be used to explore clinicopathological and genomic characteristics of these patients.