Breast

• Microcalcifications are detected during mammography
• Based on their number, size, morphology and distribution, a BI-RADS category indicative of the likelihood of malignancy is assigned (see Table 1 and 2)
• Suspicious microcalcifications are irregular and fine; nonsuspicious are coarse and chunky
• Pathologists must detect microcalcifications in glass slides that correspond to those observed in radiographs; if microcalcifications are not initially identified, they should consider submitting additional tissue, obtaining additional levels or employing polarized microscopy to identify calcium oxalate (Pathologica 2007;99:5)
• Note: microcalcifications may be absent from biopsy specimen due to retrieval failure (Radiology 2006;239:61)
• Note: it is recommended to histologically examine all vacuum assisted breast biopsy specimens, regardless of the presence or absence of microcalcifications (Eur Radiol 2008;18:925)
• Detection of calcium phosphate microcalcifications is diminished with glyoxal fixative (Eur Radiol 2008;18:925)

Table 1: BI-RADS assessment categories and likelihood of cancer (adapted from Biochim Biophys Acta Rev Cancer 2018;1869:310)

Category	Assessment	Management	Likelihood of cancer
0	Incomplete; needs additional imaging evaluation or prior mammograms for comparison	Additional imaging or comparison with prior examination(s)	N/A
1	Negative	Routine mammography screening	0%
2	Benign	Routine mammography screening	0%
3	Probably benign	Short interval (6 month) follow up or continued surveillance mammography	> 0% but ≤ 2%
4	Suspicious for malignancy 4A: Low suspicion 4B: Moderate suspicion 4C: High suspicion	Tissue diagnosis	> 2% but < 95% > 2% to ≤ 10% > 10% to ≤ 50% > 50% to < 95%
5	Highly suggestive of malignancy	Tissue diagnosis	≥ 95%
6	Known biopsy proven malignancy	Surgical excision when clinically appropriate	N/A

Table 2: Mammographic characteristic features of benign versus suspicious breast calcifications (Biochim Biophys Acta Rev Cancer 2018;1869:310, Mol Clin Oncol 2022;16:81, YouTube: Breast Imaging Calcifications - module 2 | Health4TheWorld Academy [Accessed 8 April 2024], Nov Approaches Cancer Study 2021;6:582)

Features	Typically Benign	Suspicious for Malignancy
Quantity	Few	Many
Size (diameter)	Large and chunky, 1.0 - 4.0 mm	< 0.5 mm
Shape	Coarse, round, oval, uniform	Fine, linear
Borders	Well defined, regular	Irregular, less defined
Groups	5 calcifications within 1 cm	> 5 calcification within 2 cm
Distribution	Diffuse / scattered, regional	Linear, segmental
Morphology	Eggshell-like, popcorn-like, rod-like	Amorphous, coarse heterogenous, fine pleomorphic, fine linear branching
Other associations	Skin, vascular, dystrophic, milk of calcium, suture, breast infarcts

Contributed by Agnes Ikpoto Udoh, M.D., M.B.A.


Images hosted on other servers:

Contributed by Jing He, M.D.

Which of the following characteristics is most suggestive of benign microcalcifications on mammography?

1. Fine pleomorphic calcifications
2. Linear or branching distribution
3. Round or oval shape with smooth borders
4. Segmental distribution

C. Round or oval shape with smooth borders. Benign microcalcifications commonly exhibit a round or oval shape with smooth margins, which typically suggest benign conditions like fibrocystic changes or benign breast calcifications. Answer B is incorrect because linear or branching distribution is more commonly associated with malignant lesions, particularly ductal carcinoma in situ (DCIS). Answer A is incorrect because fine pleomorphic calcifications are irregular in shape and size and have a higher likelihood of being associated with malignant lesions than the classifications that are round with smooth borders. Answer D is incorrect because segmental distribution is usually suggestive of malignancy; however, there are few reports of its association with fibrocystic change (Radiol Case Rep 2023;18:3828).

Comment Here

Reference: Microcalcifications

What is the recommended next step if microcalcifications are not initially identified in histological examination?

1. Consult with a radiologist for further imaging
2. Submit additional tissue for analysis
3. Disregard the findings as insignificant
4. Perform electron microscopy for better resolution

B. Submit additional tissue for analysis. Of the provided options, the best option would be to submit additional tissue for analysis. It would be most appropriate to first obtain additional levels before doing so, after which you should employ polarized microscopy to identify calcium oxalate crystals if still not seen on H&E. Answer A is incorrect because while consulting with a radiologist for further imaging might be a further step taken in the diagnostic process, it is not the recommended next step if microcalcifications are not initially identified in histological examination. Answer C is incorrect because disregarding the findings as insignificant without further investigation would be inappropriate and potentially harmful. Microcalcifications can be indicative of various benign and malignant conditions, so their presence or absence could have implications for diagnosis and treatment planning. Dismissing them without proper evaluation could lead to missed diagnoses or incorrect management decisions. Answer D is incorrect because electron microscopy is a highly specialized technique used for examining ultrastructural details of tissues at a very high resolution. While electron microscopy can provide detailed information, it is not routinely used for identifying microcalcifications in breast tissue.

Comment Here

Reference: Microcalcifications

A premenopausal woman is seen for bilateral breast tenderness. She is not pregnant or on hormone therapy. Mammography of the breast revealed grouped punctate and indistinct calcifications measuring 6 mm, BIRADS 4A. No lesions are seen in the other breast. A follow up biopsy is shown above. IHC showed heterogenous ER staining and positive CK5/6. What is the most likely diagnosis?

1. DCIS with microcalcifications
2. Fat necrosis with microcalcificatons
3. Invasive ductal carcinoma with microcalcificatons
4. Usual ductal hyperplasia with microcalcifications

D. Usual ductal hyperplasia with microcalcifications. The histology shows benign appearing hyperplastic ductal cells admixed with myoepithelial cells with associated microcalcifications. Answer A is incorrect because of the presence of myoepithelial cells and heterogenous ER staining. In DCIS, ER is diffuse strong positive. Answer C is incorrect because the cells appear benign with myoepithelial cells admixed with the ductal cells. Myoepithelial cells are absent in invasive breast cancer. Also, radiology had a low suspicion for malignancy. Answer D is incorrect because fat necrosis usually follows trauma and consists of cystic spaces surrounded by lipid laden (foamy) macrophages. Though histiocytes can be seen in this picture the more appropriate diagnosis is usual ductal hyperplasia.

Comment Here

Reference: Microcalcifications