Category Archives: Breast

Organ Systems, Breast

Breast – Collagenous Spherulosis

Collagenous Spherulosis is an uncommon incidental benign finding, which can be confused with other pathologies such as DCIS, carcinoma, and adenoid cystic carcinoma of the breast.

The lesions are characterized by central mucin with epithelial cells (luminal and myoepithelial) radially arranged at the periphery.

Photomicrographs
Breast - Collagenous Spherulosis
Breast – Collagenous Spherulosis
Breast - Collagenous Spherulosis
Breast – Collagenous Spherulosis
References

Resetkova, E., et. al. “Collagenous spherulosis of breast: morphologic study of 59 cases and review of the literature.”. Am J Surg Pathol. 30 (1):207. Jan 2006.    doi:10.1097/01.pas.0000179237.91515.81

Organ Systems, Breast

Breast – Fat Necrosis

Fat necrosis may sometimes present as a palpable mass, which may raise clinical concern or distress in the patient.  Approximately 1/2 of cases have a history of trauma.  Fat necrosis is also a common finding in excision specimen after a preceding biopsy.

The characteristic findings of fat necrosis include mixed inflammation (neutrophils, histiocytes, etc.), fibroblastic proliferation, and liquefactive fat necrosis.  Each of the component may vary in prominence.  The most important thing is not to mistake fat necrosis for malignancy, and not miss an area of malignancy masked by fat necrosis (AE1/AE3 or CAM5.2 may be helpful in such situations).

Photomicrographs
Fat Necrosis
Fat Necrosis
Fat Necrosis
Fat Necrosis
Fat Necrosis
Fat Necrosis with giant cell reaction
References
Kumar, Vinay, Abul K. Abbas, and Jon C. Aster. Robbins and Cotran Pathologic Basis of Disease. Ninth edition. Philadelphia, PA: Elsevier/Saunders, 2015.
Organ Systems, Breast

Breast – Epithelial Proliferations

There are many features of breast disease that encompass a wide spectrum of morphologic and radiologic findings, which have a varying risk of subsequent carcinoma.  Some of these entities are thought to be direct precursors to invasive carcinoma, and others just signify a component of future risk of invasive carcinoma.

Non-Atypical Lesions
Miscellaneous Findings
Atypical Lesions
Breast Lesions and Risk of Developing an Invasive Carcinoma
Breast Immunohistochemsitry
Organ Systems, Breast

Breast Lesions and Risk of Developing an Invasive Carcinoma

The following table and figure illustrate the risk of developing an invasive breast carcinoma based on the type of lesions previously identified.  This information does not take into consideration other factors such as race and family history (complicated topic).

Relative and Absolute Risk of Invasive Breast Carcinoma
Relative
Risk
Absolute
Risk
(lifetime)
Breast
Lesion
1
3%
1.5 – 2
5-7%
4 – 5
13-17%
8 – 10
25-30%
Breast Cancer Risk Chart
Breast Cancer Risk Chart
References

Kumar, Vinay, Abul K. Abbas, and Jon C. Aster. Robbins and Cotran Pathologic Basis of Disease. Ninth edition. Philadelphia, PA: Elsevier/Saunders, 2015. 

Organ Systems, Breast

Breast – Atypical Lobular Hyperplasia (ALH)

Atypical lobular hyperplasia is a proliferation of epithelial cells in the terminal duct-lobular unit that lacks expression of E-cadherin and fills the lobular unit (but does not expand).  Some define ALH as filling or distending <50% of the acini within an affected lobule.  There is some variation between experts as the exact differentiating line between ALH and lobular carcinoma in situ (LCIS).  It is best to think of ALH and LCIS as representing a morphologic spectrum with filling and distention of lobular acini being the measured characteristic.
 
In some cases ALH/LCIS may appear similar to DCIS or merge with areas of DCIS.  E-cadherin is a helpful marker to differentiate between these lesions.  Clinically it is important to differentiate ALH/LCIS from DCIS because LCIS/ALH is an incidental finding on mammogram and represents a risk factor for bilateral breast carcinomas.  Management is not through local excision, but surveillance and hormonal therapy dependent upon the type of lesion.  DCIS is treated through local excision because these lesions tend to be localized/focal.
 
ALH carries an increased risk of developing an invasive breast carcinoma (4-5x relative risk, 13-17% lifetime risk), while LCIS carries an 8-10x increased relative risk, 25-30% lifetime risk).  These are the same risks as ALH and DCIS, respectively.  Although ALH/LCIS risk is bilateral, while ADH/DCIS tends to be more ipsilateral. 
Breast lesions and risk of developing an invasive carcinoma
Breast Cancer Risk Chart
Breast Cancer Risk Chart
References

Kumar, Vinay, Abul K. Abbas, and Jon C. Aster. Robbins and Cotran Pathologic Basis of Disease. Ninth edition. Philadelphia, PA: Elsevier/Saunders, 2015.  p. 1050-1051

Organ Systems, Breast

Breast – Intraductal Papilloma

Introductal papilloma can have varying appearances but characteristically contain an ductal epithelial proliferation on a fibrovascular core with an intact myoepithelial layer.  Larger duct lesions are located near the nipple and typically produce a discharge (~80%).  Small duct lesions are frequently multiple and located deeper in the breast.
 
Papilloma are are associated with a slight increased risk for breast carcinoma (1.5-2x increased relative risk).  The absence of a myoepithelial layer is not characteristic of a typical papilloma, and likely represents a different papillary lesion.
Breast lesions and risk of developing an invasive carcinoma
Breast Cancer Risk Chart
Breast Cancer Risk Chart
Reference 

Kumar, Vinay, Abul K. Abbas, and Jon C. Aster. Robbins and Cotran Pathologic Basis of Disease. Ninth edition. Philadelphia, PA: Elsevier/Saunders, 2015. p. 1048-1051