Primary osteogenic sarcoma of the breast is a rare clinical entity with few cases described in the literature. Unfortunately, the prognosis for these patients is poor when compared to invasive carcinomas of the breast. We report a case of a 58-year-old female who developed a primary osteogenic sarcoma of the breast five years after being treated for invasive carcinoma of the ipsilateral breast without the use of radiotherapy.
Breast lumps are the most common presenting complaint (40%) among patients presenting to general practice clinics with breast symptoms [
Breast cancer is the most prevalent form of cancer observed in females globally, with 2.1 million persons affected each year. It accounts for the most cancer-related deaths among women with 627,000 dying from the disease in 2018 [
Carcinomas account for the majority of breast cancers with the contribution of sarcomas being less than 1% [
When compared to breast carcinoma, primary osteogenic sarcoma has a sombre 5-year survival of 38% [
We report the case of a patient who developed a primary osteogenic sarcoma of the breast five years after being treated for invasive carcinoma of the ipsilateral breast.
A 58-year-old female presented with a 3 cm mass in the lower inner quadrant of the left breast. Ultrasound and mammography revealed a Breast Imaging Reporting and Data System [
Pathological examination revealed a T2 N0 M0 grade 1 invasive ductal carcinoma with 14 examined lymph nodes showing no evidence of metastases. The patient subsequently refused adjuvant radiation and chemotherapy.
Five years after her surgery, the patient presented with a painless, mobile, 15 cm mass involving the upper and lower outer quadrants of the left breast. No evidence of nipple retraction or discharge was observed. Mammography revealed a BI-RADS 5 lesion. A core biopsy showed breast tissue containing areas of bone formation with partially calcified osteoid material surrounded by stellate and spindle-shaped stromal cells. There was also osteoclast-like giant cells present.
Contrast-enhanced computed tomography (CT) of the chest and abdomen revealed a large lobulated left breast mass with cystic and calcific foci, measuring
The patient refused mastectomy and chose to have a wide local excision of the breast mass (see Figure
(a) Preoperative marking of the breast mass. (b) Surgical specimen after wide local excision.
Pathologic examination of the mass showed osteogenic sarcoma with malignant cells admixed with neoplastic woven bone and frequent mitotic figures (see Figure
(a) Malignant tumour with surrounding breast parenchyma (H&E, ×4). (b) Malignant tumour composed of neoplastic woven bone intimately admixed with pleomorphic tumour cells (H&E, ×10). (c) Neoplastic woven bone exhibiting eosinophilic osteoid along with high pleomorphic tumour cells (H&E, ×10). (d) Pleomorphic tumour cells having vesicular chromatin and conspicuous nucleoli showing both osteoblastic and osteoclastic (giant cell) subtypes (H&E, ×40).
A technetium-99 methylene diphosphonate bone scan was undertaken, and no evidence of primary osteosarcoma arising from bone was detected, indicating that the breast lesion was primary osteosarcoma.
Extraskeletal osteogenic sarcoma is a rare subtype of sarcoma accounting for 0.01% of all soft tissue sarcomas [
Primary osteogenic sarcoma of the breast (POSB) typically presents as a painless mass with no attendant evidence of nipple discharge or retraction [
Of note, prior radiation and trauma to the affected area have been described as being present in 10% and 15% of patients, respectively, with extraskeletal osteogenic sarcomas [
Useful imaging techniques for the evaluation of patients with POSB include mammography, CT, and bone scintigraphy. Mammographic findings are similar to that of fibroadenoma and may lead to misdiagnosis [
While imaging is useful in the workup of a patient with POSB, the diagnosis cannot be made without pathological assessment. The utility of both fine needle aspirate and core needle biopsy in the preoperative workup of patients with POSB has been described in the literature [
Numerous tumours of the breast can produce cartilage, osteoid, and bone and hence must be included in the differential diagnosis for a case of POSB. The main differentials are metaplastic carcinoma, malignant phyllodes tumours with osteosarcomatous differentiation (or heterologous elements), and benign heterotopic ossification/fasciitis ossificans [
Given the rarity of this condition, there is a paucity of data to guide management. Similar to sarcomas arising at other locations, POSB tends to be locally aggressive tumours with a propensity to spread via the blood as opposed to the characteristic lymphatic spread observed in carcinoma of the breast [
Forty-one per cent of patients with POSB develop metastases which highlight the need for effective adjuvant therapy [
Primary osteogenic sarcoma of the breast is a rare tumour which can mimic a carcinoma on clinical presentation. Thorough pathological examination, as well as investigations to rule out a bony primary, is necessary before a diagnosis is made. Given the limited available data to guide management, further research is needed to optimise the treatment of this aggressive disease.
Informed consent was obtained from the patient prior to the publication of this article.
The authors declare that there is no conflict of interest regarding the publication of this paper.