Male Breast Mass: Rare Case of Chest Wall-Invading Lung Cancer

Medical case reports are highlighting the critical importance of maintaining a broad differential diagnosis when evaluating breast masses in male patients, as these lesions may occasionally be metastatic manifestations of lung cancer rather than primary breast malignancies.

Recent documentation in the journal Cureus describes a rare clinical presentation where non-small cell lung carcinoma manifested as a retroareolar tumor in a male patient. The case emphasizes that such lesions can present as fixed and painful masses within the chest wall and breast region.

Diagnostic Challenges in Male Breast Masses

The identification of a breast lump in men often leads to an initial clinical suspicion of primary male breast carcinoma. However, research indicates that these masses can be the result of distant metastases from other primary sites, particularly the lungs.

A case report published on November 11, 2025, in the Indian Journal of Surgery details a 43-year-old male who presented with a left-sided breast lump and progressive right hip pain over a four-month period. The patient’s symptoms began with a persistent dry cough and severe hip pain, followed by hemoptysis, before the breast lump appeared.

While initial suspicions centered on primary breast cancer, further imaging revealed widespread FDG avid metastatic disease. The malignancy involved the left anterior chest wall, the right pulmonary hilum, mediastinal lymph nodes, the brain, the liver, and the proximal femur.

The Role of Tissue Diagnosis and Immunohistochemistry

Accurately distinguishing between primary breast malignancies and metastatic lesions is essential for determining the correct treatment path. The use of immunohistochemical staining is a critical tool in this process.

In the case of the 43-year-old patient, core needle biopsies of the breast mass and an open biopsy of the right femur revealed metastatic poorly differentiated adenocarcinoma. To determine the origin of the cancer, clinicians used specific markers:

• The staining was positive for thyroid transcription factor-1 (TTF-1), which is consistent with a primary pulmonary origin.
• The staining was negative for GATA3, a marker typically associated with breast cancer.

The report notes that fine needle aspiration cytology alone may miss the diagnosis, whereas core needle biopsy or excisional tissue provides more definitive results.

Clinical Implications and Rare Presentations

The ability to recognize non-mammary primaries presenting as breast masses is vital to prevent unnecessary surgical interventions and to guide appropriate systemic therapy. In the instance of the 43-year-old patient, orthopedic surgical intervention for a pathological femoral fracture allowed the patient to become ambulatory and independent within two days.

Other literature has documented similar rare occurrences. One report published via the National Center for Biotechnology Information (NCBI) detailed a case where a mass in the left breast was histopathologically diagnosed as a metastasis of squamous cell lung carcinoma.

These combined cases underscore a broader medical necessity: clinicians must look beyond the immediate site of a tumor to consider systemic malignancies, especially when presenting symptoms include respiratory issues such as a persistent cough or hemoptysis.