I have a new cutaneous lesion on my chest and had axillary pain two weeks ago; could this represent a dermatologic condition or malignancy, and what evaluation is recommended?

Evaluation and Management

You need an urgent clinical examination of the chest lesion with axillary ultrasound as the initial imaging study, followed by diagnostic mammography to evaluate for underlying breast pathology. This presentation—a new cutaneous lesion on the chest with recent axillary pain—requires prompt evaluation to exclude breast cancer with cutaneous metastasis or primary breast malignancy with nodal involvement.

Initial Diagnostic Approach

Clinical Assessment Priority

The combination of a chest skin lesion and axillary symptoms raises concern for:

• Breast cancer with cutaneous metastasis (can present as skin nodules, plaques, or ulcerated lesions on the chest wall) 1
• Occult breast malignancy presenting with axillary adenopathy
• Accessory breast tissue pathology (can develop tumors and cause axillary pain) 2
• Benign dermatologic conditions (though less likely given the axillary symptoms)

Recommended Imaging Algorithm

Step 1: Axillary Ultrasound (Primary Initial Test)

• Ultrasound of the axilla is the most appropriate initial imaging study for evaluating axillary symptoms and masses 3
• Can characterize lymph node morphology and guide biopsy if suspicious nodes are identified
• Multiple studies support US as the primary modality to differentiate benign from malignant axillary findings 3

Step 2: Diagnostic Mammography ± Digital Breast Tomosynthesis

• Must be performed as a complementary study to evaluate the breast for underlying lesions when axillary lymphadenopathy is present 3
• According to NCCN guidelines, diagnostic mammography and/or DBT complement axillary US by evaluating for occult breast primary 3
• Essential even if the chest lesion appears dermatologic, as breast cancer cutaneous metastases can be the presenting sign 4, 1

Step 3: Biopsy of Suspicious Findings

• If axillary US reveals abnormal lymph nodes: US-guided core needle biopsy 3
• For the chest skin lesion: skin punch biopsy if clinical examination suggests possible malignancy 4
• Both biopsies may be necessary to establish diagnosis, as cutaneous metastases can occur without palpable breast mass 4

Critical Clinical Pearls

Red Flags Requiring Urgent Evaluation

• Ulcerated or crusted skin lesions on the chest wall (can represent cutaneous metastases) 1
• Firm, flesh-colored to red nodules or plaques on the chest (classic presentation of breast cancer skin metastases) 1
• Persistent axillary pain with skin changes (may indicate accessory breast tissue pathology or nodal disease) 2

Common Diagnostic Pitfalls

• Do not assume a chest skin lesion is purely dermatologic without imaging evaluation of the breast and axilla 5, 1
• Breast cancer cutaneous metastases can mimic benign conditions (cysts, dermatitis, infections) and delay diagnosis 1
• Occult invasive lobular carcinoma can present with axillary skin lesions while breast imaging remains unremarkable 4
• Male patients with chest wall skin lesions require the same thorough evaluation, as breast cancer can present this way 5

What NOT to Do

• Do not order CT chest or PET/CT as initial imaging—these are not appropriate first-line tests for evaluating axillary masses without confirmed malignancy 3
• Do not rely on mammography alone—it has insufficient sensitivity for axillary evaluation and must be paired with US 3
• Do not perform MRI breast as initial imaging—reserve this for defining disease extent after malignancy is confirmed 3

Timeline and Follow-up

Imaging should be completed within 1-2 weeks given the concerning presentation. If imaging reveals:

• Suspicious lymph nodes or breast lesions: Proceed immediately to biopsy
• Normal imaging but persistent concerning skin lesion: Obtain dermatologic consultation and skin biopsy
• Confirmed malignancy: Refer urgently to surgical oncology and medical oncology for staging and treatment planning

The key principle is that cutaneous lesions on the chest with axillary symptoms cannot be dismissed as benign dermatologic conditions until breast cancer is definitively excluded through appropriate imaging and tissue diagnosis 4, 1.