GRAnulomatous MAstitis REGistry Study

NCT07422870 | Not Yet Recruiting DMC

• 1 other identifier: EUBREAST-15
• Study Type: observational
• Target: 1,000
• Locations: 1 country
• Sites: 2

Brief Summary

Idiopathic granulomatous mastitis (IGM) is a rare benign inflammatory breast condition with unknown cause, affecting approximately 2.4 per 100,000 women aged 20-40 years. Patients experience severe local symptoms including pain, redness, and recurrent abscesses that can last weeks to months and often mimic inflammatory breast cancer. Due to its rarity, mostly case reports and case series exist in the literature, leading to limited knowledge about risk factors, optimal treatment strategies, and clinical outcomes. The GRAMAREG study is the first European registry for patients with histologically confirmed idiopathic granulomatous mastitis. This retrospective/prospective observational cohort study aims to systematically evaluate the incidence, diagnostic features, clinical course, treatment strategies, and patient outcomes of this uncommon disease. The study collects both retrospective data (from January 1, 2015 onwards) and prospective data from participating sites across Europe. All diagnostic and therapeutic procedures are conducted according to institutional standards in clinical routine, as this is a non-interventional study. Patients in the prospective cohort are followed for up to 5 years to document symptom duration and recurrence rates.

Conditions

Idiopathic Granulomatous Mastitis; Granulomatous Mastitis

Keywords

Idiopathic granulomatous mastitis; IGM; Granulomatous mastitis; Cystic neutrophilic granulomatous mastitis; CNGM; Inflammatory breast disease; Benign breast disease; Chronic mastitis; Non-lactational mastitis; Breast inflammation; Patient registry; Cohort study; granulomatous lobular mastitis

Outcome Measures

Primary Outcomes (2)

• Proportion of Patients Presenting with Specific Symptoms

  Percentage of patients presenting with specific clinical symptoms including pain, redness, and palpable breast mass at initial presentation

  At initial diagnosis (baseline)

• Duration of Symptoms Depending on Treatment Strategy

  Time from initial symptom onset to symptom resolution measured in weeks or months, stratified by treatment approach (systemic treatment, surgical intervention, conservative management)

  From initial diagnosis through symptom resolution, up to 5 years

Secondary Outcomes (6)

• Type and Duration of Systemic Treatment

  From initial diagnosis through completion of treatment, up to 5 years

• Number of Surgeries Performed

  From initial diagnosis through 5 years follow-up

• Recurrence Rate

  At 1, 3, and 5 years after first diagnosis

• Risk Factors Associated with Recurrence

  At 1, 3, and 5 years follow-up

• Time to Histological Confirmation

  At baseline (from retrospective chart review or patient recall)

Study Arms (1)

Idiopathic Granulomatous Mastitis Patients

Female and male patients ≥18 years old with histologically confirmed idiopathic granulomatous mastitis (IGM) or cystic neutrophilic granulomatous mastitis (CNGM) diagnosed after January 1, 2015. Histological confirmation obtained by minimally invasive biopsy or on surgical specimen by local pathology. Excludes patients with secondary granulomatous mastitis due to tuberculosis, sarcoidosis, fungal and parasitic infection, or foreign body.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients diagnosed with histologically confirmed idiopathic granulomatous mastitis (IGM) or cystic neutrophilic granulomatous mastitis (CNGM) at participating European breast centers and hospitals. The population includes both retrospectively identified patients (diagnosed January 1, 2015, through Study Site activation) and prospectively enrolled patients (diagnosed after Study Site activation). IGM predominantly affects women of childbearing age, mostly parous, and more frequently of non-white ethnicity, though both males and females ≥18 years are eligible.

You may qualify if:

• Histologically confirmed idiopathic granulomatous mastitis OR cystic neutrophilic granulomatous mastitis by local pathology (minimally invasive biopsy or histological confirmation on surgical specimen)
• First histological confirmation after January 1, 2015
• Female or male patients ≥18 years old
• Signed informed consent form for all patients included in prospective part of the study (patients presenting with idiopathic granulomatous mastitis after activation of the study at Study Site)

You may not qualify if:

• Patients with suspicion of idiopathic granulomatous mastitis but without histological confirmation
• Suspicion of OR confirmed secondary granulomatous mastitis due to:
• Tuberculosis, Sarcoidosis, Fungal infection, Parasitic infection, Foreign body reaction

Sponsors & Collaborators

• European Breast Cancer Research Association of Surgical Trialists: lead

Study Sites (2)

University Hospital Düsseldorf

Düsseldorf, North Rhine-Westphalia, 40225, Germany

Location

Department of Gynecology and Obstetrics University Hospital Schleswig-Holstein

Lübeck, Schleswig-Holstein, 23562, Germany

Location

MeSH Terms

Conditions

Granulomatous Mastitis; Mastitis; Cystic Fibrosis

Condition Hierarchy (Ancestors)

Puerperal Disorders; Pregnancy Complications; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases; Pancreatic Diseases; Digestive System Diseases; Lung Diseases; Respiratory Tract Diseases; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Infant, Newborn, Diseases

Central Study Contacts

Natalia Krawczyk, PD Dr. med.

CONTACT

+49 0211 0; Natalia.Krawczyk@med.uni-duesseldorf.de

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: OTHER
• Target Duration: 5 Years
• Sponsor Type: NETWORK
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 13, 2026
• First Posted: February 20, 2026
• Study Start: April 1, 2026
• Primary Completion (Estimated): April 1, 2031
• Study Completion (Estimated): April 1, 2036
• Last Updated: February 27, 2026

Record last verified: 2026-02

Locations

DE (2)