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Breast Lump/Mass - Differential Diagnosis, Workup


Differential diagnosis for breast lump (other than carcinoma): **depends on age, pre- vs post- menopausal

1)  Fibrocystic condition: painful, often multiple, usually bilateral masses in the breast. Rapid Fluctuation in the size is common. Frequently, pain occurs or worsens and size increases during premenses. Most common age is 30-50. Increased risk of breast cancer if they have a variant with epithelial proliferation 

2)  Fibroadenoma: most common benign neoplasm in young woman. More frequent and occurs at younger age in black women. Multiple tumors in 10-15% pts.
Typically round, rubbery, discrete, movable, non-tender 1-5cm, discovered accidentally.

3)  Phyllodes tumor: fibroadenoma-like tumor with cellular stroma that grows rapidly, recurs locally if no wide margins. Can be benign or malignant. Metastasizes to lungs not LN.

4) Fat necrosis: rare lesion of breast of clinical importance because it produces a mass accompanied by skin or nipple retraction*** that is indistinguishable from CA even with imaging studies. Trauma is presumed cause, but only 50% pt give hx of trauma. Ecchymosis occasionally. Biopsy to diagnose.

5) Breast abscess: rare to have infection in non-lactating breast. Subareolar abscess may develop in young or middle-aged women who are not lactating. Tend to recur after I&D unless area is explored with excision of involved lactiferous ducts at base of the nipple. Always consider inflammatory breast cancer. Incision and biopsy is indicated if suspected abscess or cellulitis does not resolve promptly with abx.

6) Mastitis, postpartum - occurs sporadically in nursing mothers shortly after returning home. Staph aureus is causative agent. Inflammation usually unilateral. First time nursing women get it more often. Regular mastitis : Frequently begins within 3 months after delivering, may start with a sore or fissured nipple. Treat with against PCN resistant staph with dicloxacillin or cephalosporin 500mg po q6h x5-7days, regular emptying of breast by nursing. Should respond within 3 days. Abscess can be prevented if starting abx before suppuration begins.

**Physical exam in this patient gives us a sense of her staging and prognosis. With skin involvement she meets criteria for Stage 3B, which carries a 5 and 10 year survival of 30% and 20%, respectively. 

**Remember to do breast exams with patient sitting first, check supraclav + axillary lymph nodes, inspect breasts with patient's arms at sides, above head, and on hips to flex pec muscles. Then inspect and examine breast with patient supine.



 Stage                     TMN            5 year survival    10 year survival 
 0  Tis (carcinoma in situ), N0, M0  95  90
 1  T1 (2cm or less), N0, M0  85  70

T0, N1 (mobile ipsi ax LN), M0 

T1, N1, M0

T2 (2-5cm), N0, M0

 70  50

T2, N1, M0  

T3 (>5cm), N0, M0  

 60  40

T0-T2, N2 (fixed ipsi ax LN or ipsi internal mammary LN), M0,

T3, N0-1, M0  

 55  30
 3B  T4 (any size with extension to chest wall or peau d'orange or ulceration of skin breast or satellite skin nodules on ipsilateral breast), N0-2, M0            30  20
 3C Any T, N3 (mets in ipsi infraclavicular LN, ipsilateral IMLN and AXLN, or ipsilateral supraclavicular LN), M0                        
 4  any T, any N, M1  5-10%  2%


Work-up of breast lump: The key is pre-menopausal or post-menopausal status and your clinical suspicion. If high suspicion- do MMG and biopsy.

A breast mass in pre-menopausal woman (our case) (see attached flow chart)
- Clinically malignant: MMG, Biopsy, preop eval and counseling
- Not clinically malignant: do MMG or US.
US: cystic, then aspirate. If non-bloody fluid and it resolves then re-examine.

     If it persists, then excise.

     If it resolves, then routine follow-up
US: no abnormality or solid mass, but not malignant appearing, then biopsy or re-examine after next menses or in 1-4 mo.

     If it persists, excise.

     If it resolves, then routine follow-up
US: appears malignant, then biopsy


If you cannot confirm patient’s suspicions of a lump on exam and the imaging is negative, then repeat in 2-3 months, preferable 1-2 weeks after onset of menses.


  • Most breast cancers are found in the upper outer quadrant of the breast. (60% breast cancers occur in Upper Outer, 15% at Upper Inner and Lower Outer each, 5% Lower Inner zones)



Paget carcinoma:

  • "Paget carcinoma is not common (about 1% of all breast cancers). It affects the nipple and may or may not be associated with a breast mass. The basic lesion is usually a well differentiated infiltrating ductal carcinoma or a ductal carcinoma in situ (DCIS). The ducts of the nipple epithelium are infiltrated, but gross nipple changes are often minimal, and a tumor mass may not be palpable.

  • "Because the nipple changes appear innocuous, the diagnosis is frequently missed. The first symptom is often itching or burning of the nipple, with superficial erosion or ulceration. These are often diagnosed and treated as dermatitis or bacterial infection, leading to delay or failure in detection. The diagnosis is established by biopsy of the area of erosion. When the lesion consists of nipple changes only, the incidence of axillary metastases is less than 5%, and the prognosis is excellent. When a breast mass is also present, the incidence of axillary metastases rises, with an associated marked decrease in prospects for cure by surgical or other treatment."

Inflammatory carcinoma:

"Inflammatory Carcinoma: This is the most malignant form of breast cancer and constitutes less than 3% of all cases. The clinical findings consist of a rapidly growing, sometimes painful mass that enlarges the breast. The overlying skin becomes erythematous, edematous, and warm. Often there is no distinct mass, since the tumor infiltrates the involved breast diffusely. The inflammatory changes, often mistaken for an infection, are caused by carcinomatous invasion of the subdermal lymphatics, with resulting edema and hyperemia. If the practitioner suspects infection but the lesion does not respond rapidly (1–2 weeks) to antibiotics, biopsy should be performed. The diagnosis should be made when the redness involves more than one-third of the skin over the breast and biopsy shows infiltrating carcinoma with invasion of the subdermal lymphatics. Metastases tend to occur early and widely, and for this reason inflammatory carcinoma is rarely curable. Radiation, hormone therapy, and chemotherapy are the measures most likely to be of value rather than operation. Mastectomy is indicated when chemotherapy and radiation have resulted in clinical remission with no evidence of distant metastases. In these cases, residual disease in the breast may be eradicated."


Giuliano Armando E, Hurvitz Sara A, "Chapter 17. Breast Disorders" (Chapter). McPhee SJ, Papadakis MA, Tierney LM, Jr.: CURRENT Medical Diagnosis & Treatment 2010:



Remember your health care maintenance/cancer screening: 

  • Self Breast Exam (SBE) has not been shown to improve survival: If premenopausal wants to do SBE, it should be done 7-8 days after menses start.
  • Women 20-40 y.o.: CBE q2-3 years as part of routine medical care.
  • Women over 40 y.o.: annual CBE
  • Mammography (MMG) between age 40-50 y.o.: individualized decision 
  • MMG age 50-69 up to 74 y.o., q1-2 years 
  • Inconclusive evidence for screening MMG in women>70 


(Katharine Cheung MD, 8/2/10)