Potentially Malignant microcalcification by texture

The presence of microcalcifications in an initial screening may or may not be indicative of acute or potential breast cancer. Research as to the predictive value of different microcalcification presentations is ongoing. However, there is reasonable evidence to suggest that of the three most common microcalcification textures, a 'casting' appearance has the highest probability of accompanying DCIS. A 'powderish' appearance is the least likely predictor of DCIS, at approximately 47%, while the more varied 'crushed stone' presentation accompanies DCIS about 61% of time.

 

 
Microcalcification texture Probability of DCIS Most frequent grade
Powderish:fine, indiscernible, cotton ball 47% Low Grade
Crushed Stone: coarse, granular, angular, broken needle tip, arrowhead, spearhead 61% low to Intermediate
Casting 96% High grade

 

The use of the term "grade" in this context refers to how the cells might appear under a microscope, in what is referred to as the 'histological evaluation'. This implies that there is a relationship between the presence of certain kinds of microcalcifications and changes occuring in both the appearance and distribution of affected cells. "Low grade" cellular changes are often referred to simply as 'ductal hyperplasia'. An 'intermediate grade' suggests noticeable changes in the distribution and actual appearance of cells,and often contributes to a vaguely defined diagonsis of 'DCIS'. 'High grade' more or less refers to very noticeable changes in the appearance of cells and probable infiltration into and beyond the duct lining (IDC). An experienced physician has a 'feel' for the behavior of certain cells and cellular appearances. The combination of microcalcification textures with particular cell presenations gives a clearer picture of probable cancer malignancy.

 

Histological grade frequently associated with microcalcification type

Grade 1 (low) Regular nuclei without any necrosis.
Grade 2 (intermediate) Mild to moderate nuclear variation, usually without necrosis.
Grade 3 (high) Large cells with irregular nuclei and a nucleolus, with necrosis in approximately 30% to 40% of cases.

(' Necrosis' refers to evidece of cells which have 'died' )

 

Chemical changes in breast microcalcifications can indicate risk of malignancy

Microcalcifications are not just significant in initial breast cancer screening. Studies have shown that the percentage of the microcalcification composed of carbonate actually decreases as the tumor progresses from a benign to a malignant state. Checking the chemical composition of the microcalcification can be part of 'follow-up' mammograms and evaluations to check if a suspcious tumor is becoming more malignant. Increased carbonate content in a microcalcification indicates that a cancer is growing in the viscinity.

 

breast microcalcifications xray

 

Casting microcalcifications tend to be associated with more aggressive breast cancers

Casting breast microcalcifications, when found in women who turn out to have multifocal DCIS, can often have higher incidence lymph node metastasis. Casting microcalcifications tend to be indicators of increased risk for systemic disease, and the presence of casting microcalcifications can influence adjuvant therapy decisions once the breast cancer is fully staged.

 

It should be noted that microcalcifications discovered on a breast cancer screening mammogram are a means of detecting the cancer at an early stage, frequently as ductal carcinoma in situ. DCIS has an extremely high cure rate , generally over 95%. Casting microcalcifications are perhaps the most serious indicators of the different textures frequently encountered, but their presence is not a significant prognostic indicator. Other factors traditionally associated with breast cancer staging and grading such as tumor size, nuclear features, and lymph node metastasis. Casting microcalcifications tend to be associated with tumors that have already reach a higher grade based on traditional measurements. Breast tumors with casting-type calcifications tend to be of a high grade, and with negative HR and PR hormone receptor statues, and also frequently tend to accompany HER2 positive breast tumors. However, casting microcalcifications have also been associated with a 'micropapillary' form of DCIS, which has been found to be highly aggressive.

 

Women with 'crushed stone' microcalcifications, overall, tend to have a 15 year survival rate of 87% to 95%. However, it would appear that breast tumors associated with casting-type microcalcifications tend exhibits a more aggressive behavior, and a poorer prognosis. Overall, the average relaspse-free interval for patients with confirmed breast cancer associated with casting-type microcalcifications, is about 27 months. Relapse free interval and overal surival is significantly higher for patients with breast tumors not accompanined by casting microcalcifications, with an average duration of about 5 years.

 

References

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  6. Månsson, E., Bergkvist, L., Christenson, G., Persson, C. and Wärnberg, F. (2009), Mammographic casting-type calcifications is not a prognostic factor in unifocal small invasive breast cancer: A population-based retrospective cohort study. Journal of Surgical Oncology, 100: 670–674.
  7. Haka AS, Shafer-Peltier KE, Fitzmaurice M, Crowe J, Dasari RR, Feld MS.Identifying microcalcifications in benign and malignant breast lesions by probing differences in their chemical composition using Raman spectroscopy. Cancer Res. (Sept. 2002) 62(18):5375-80.
  8. Johnson J. M., Dalton R. R., Wester S. M., Landercasper J., Lambert P. J. Histological correlation of microcalcifications in breast biopsy specimens. Arch. Surg.(1999), 134: 712-716.
  9. Peacock, C. Mammographic casting-type calcification associated with small screen-detected invasive breast cancers: is this a reliable prognostic indicator? Clinical Radiology, Volume 59, Issue 2, Pages 165-170.
  10. Tot, T., Tabar, L. Mammographic–Pathologic Correlation of Ductal Carcinoma In Situ of the Breast Using Two- and Three-Dimensional Large Histologic Sections. Seminars in Breast Disease. (September 2005) Volume 8, Issue 3, Pages 144-151
  11. Palka, I., Ormandi, K., Gaal, Szilvia, Doba, K., Kahan, Z. Casting-type calcifications on the mammogram suggest a higher probability of early relapse and death among high-risk breast cancer patients. Acta oncologica 2007, vol. 46, no8, pp. 1178-1183

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Copyright Steven B. Halls, MD Last edited 01-December-2010

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