Differential Diagnosis
The patient presents with fat stranding of the subscapularis, elevated WBC, ESR, and CRP labs, a history of breast cancer, and supraclavicular swelling. Here's a differential diagnosis organized into categories:
Single Most Likely Diagnosis
- Metastatic breast cancer to the subscapularis region: This is likely due to the patient's history of breast cancer and the presence of supraclavicular swelling, which can be a sign of metastasis. The elevated inflammatory markers (WBC, ESR, CRP) may indicate an inflammatory response to the tumor.
Other Likely Diagnoses
- Infectious process (e.g., abscess or cellulitis) in the subscapularis region: The elevated WBC, ESR, and CRP labs suggest an infectious or inflammatory process. Given the location and the patient's history, an infection in this area could be a consideration.
- Lymphoma: Supraclavicular swelling can be associated with lymphoma, and the patient's history of cancer increases the likelihood of a second primary malignancy. The inflammatory markers could be elevated in response to the lymphoma.
- Metastatic disease from another primary cancer: Although the patient has a history of breast cancer, it's possible that there's a second primary cancer that has metastasized to the subscapularis region.
Do Not Miss Diagnoses
- Septic arthritis or osteomyelitis of the shoulder: These conditions can present with similar symptoms and would require prompt antibiotic treatment to prevent serious complications. The elevated inflammatory markers support this possibility.
- Spinal cord compression or metastasis: Given the patient's history of breast cancer, spinal cord compression or metastasis to the spine is a possibility that could present with pain and swelling in the supraclavicular region. This is a medical emergency that requires immediate attention.
Rare Diagnoses
- Soft tissue sarcoma: Although rare, a soft tissue sarcoma in the subscapularis region could present with similar symptoms and would be an important diagnosis to consider.
- Rheumatologic disease (e.g., rheumatoid arthritis, polymyalgia rheumatica): These conditions can cause elevated inflammatory markers and musculoskeletal symptoms, but they would be less likely given the patient's history of cancer and the specific location of the symptoms.
- Granulomatous disease (e.g., tuberculosis, sarcoidosis): These conditions can cause chronic inflammation and could potentially present with similar symptoms, although they would be less likely given the acute presentation and the patient's history.