Calcium Oxalate Is Associated With Benign Breast Tissue:Can We Avoid Biopsy?

Abstract

Breast biopsies are commonly performed for abnormal, usually clustered, calcifications detected by mammography. Calcium phosphate is the predominant form of calcium seen in breast tissue and is frequently associated with malignancy. Calcium oxalate, which can also be present in breast tissue, has been exclusively associated with benign lesions. Thus, if mammography could distinguish calcium phosphate from calcium oxalate, biopsy could be avoided in some patients. Pathologic findings and corresponding mammograms of 55 patients who underwent biopsy for abnormal calcifications were reviewed. The authors evaluated such pathologic features as type of calcification, anatomic location, and association with fibrocystic changes or carcinoma. Mammographically, calcifications were categorized by size, distribution, and morphology, and each was assigned a density rating of low, medium, or high. Of the 55 cases, 41 contained calcium phosphate only, 8 contained calcium oxalate only, and 6 contained both. If only calcium oxalate was present, the calcium was always associated with benign epithelium. Of 47 cases, calcium phosphate was associated with benign breast disease in 28 and with carcinoma in 19. Five of six cases with both calcium phosphate and calcium oxalate contained carcinoma; calcium phosphate was seen in the carcinoma area in all five. Radiologically, calcium phosphate was typically medium to high density, whereas calcium oxalate was characterized as amorphous, low to medium density. Other low-density calcifications were almost always benign, unless pleomorphic in shape. Although further work is necessary to confirm these findings, it appears that, radiologically, low-density, amorphous, calcifications, even if clustered, are associated with benign breast disease, and may represent calcium oxalate. Patients with such calcifications may be managed conservatively.

Exfoliative Cytology of a Lymphoepitheliomalike Carcinoma in a Cervical Smear

“…10,15 However, there are a number of radiologic-pathologic discrepancies. Failure to observe the corresponding quantity of calcium seen in radiographs is related to the fact that calcium may occur not only as CaP but also as CaOx; the latter is not stained with hematoxylin and eosin but is readily detected by its birefringence in polarized light.…”

“…In a study of 55 cases, if only CaOx was present, the calcium was always associated with benign epithelium. 15 In 47 cases, CaP was associated with benign breast disease in 28 and with carcinoma in 19. Five of six cases with both CaP and CaOx contained carcinoma; CaP was seen in the carcinomatous area in all five.…”

“…10,11,14 CaOx has been exclusively associated with benign and borderline lesions, including atypical lobular hyperplasia and lobular carcinoma in situ. 6,7,14,15 CaP has been well characterized, but little is known about CaOx. CaOx in breast cyst fluid should be regarded as a particular type of calcification, easily overlooked with conventional light microscopy.…”

Histological correlation of mammographically detected breast calcifications – A need for rational protocols

“…Calcium oxalate, which can also be present in breast tissue, has been almost exclusively associated with benign lesions. 40 Both forms of calcium are radio-opaque and can produce a mammographic calcification. Polyhedral microcalcifications in the mammogram have been suggested to correlate with the histological presence of calcium oxalate crystals.…”

Microcalcifications as elastic scatterers under ultrasound

“…Although hydroxyapatite MCs are associated with carcinoma, and hence the focus of our model, benign microcalcifications are more typically composed of calcium oxalate [15], [20]. Calcium oxalate has been reported in breast MCs in primarily its dihydrate form as well as its monohydrate form, of which to our knowledge only the monohydrate form has been investigated with regard to its acoustic properties [15], [21]- [23].…”