Metaplastic carcinoma of the breast with widespread telangiectatic form of osteosarcomatous differentiation

Abstract

Metaplastic carcinoma of the breast with widespread telangiectatic form of osteosarcomatous differentiationTo the Editor: Metaplastic carcinoma (MC) of the breast is relatively rare among invasive breast cancers. MC represents a heterogeneous group of neoplasms that show a variety of appearances which can be classified into five groups according to the 2012 World Health Organization classification of breast tumours: low-grade adenosquamous carcinoma; fibromatosis-like MC; squamous cell carcinoma; spindle cell carcinoma; and MC with mesenchymal differentiation. 1 In particular, MC with heterologous mesenchymal components is very uncommon. We describe a case of MC that showed widespread telangiectatic form of osteosarcomatous differentiation, and highlight the clinicopathological findings.A 73-year-old woman presented with a right subareolar enlarging cystic mass that had been identified 3 months earlier, during follow-up for gastric cancer. She had no history of breast tumor. The lesion enlarged from 13 to 40 mm within the 3 months from first identification. Aspiration cytology and core needle biopsy were performed, but a diagnosis could not be reached due to inadequate samples. After intraoperative excision biopsy revealed malignancy, right mastectomy and sentinel lymph node dissection were performed. DISCLOSURE STATEMENTNone declared.

From breast to bone: a case of metaplastic breast carcinoma with osteosarcomatous differentiation

“…This heterogeneous group of neoplasms can be histologically classified into six distinct groups according to the World Health Organization 2019 classification of breast tumours: (i) low‐grade adenosquamous carcinoma, (ii) fibromatosis‐like metaplastic carcinoma, (iii) spindle cell carcinoma, (iv) squamous cell carcinoma, (v) metaplastic carcinoma with heterologous mesenchymal differentiation and (vi) mixed metaplastic carcinoma 3 . Heterologous mesenchymal differentiation, as in this case, is particularly uncommon, representing 0.2% of breast carcinomas 4 . The occurrence of metaplastic carcinoma is largely sporadic, although the spindle cell subtype may occur from pre‐existing breast lesions 5 …”

“…However, the literature for optimal management of metaplastic carcinoma is limited 4 and it is unclear whether matrix‐producing malignant breast tumours should be managed as sarcoma or as per the usual principles of ductal carcinoma. One study, where the majority of patients with matrix‐producing metaplastic breast carcinoma received radiotherapy or chemotherapy, revealed that chemotherapy was associated with longer survival, excluding pT3 and pT4 cases, and radiotherapy did not correlate with outcome.…”

Imaging findings of primary breast telangiectatic osteosarcoma: a case description

“…One of them was a local recurrence of a phyllodes tumor with differentiation to TOS in the breast in a 50-year-old woman with a two-time history of phyllodes tumor excision ( 5 ). The other one was a mammary metaplastic carcinoma with telangiectatic form of osteosarcomatous differentiation in a 73-year-old woman ( 6 ). The overview of these two cases is shown in Table 1 .…”

“…TOS of the mammary gland is extremely rare and to our knowledge, no reliable data of incidence is readily available. Two isolated case reports have described TOS in intimate association with recurrent phyllodes tumor or metaplastic carcinoma of the mammary gland ( 5 , 6 ). In this case report, we describe TOS of the breast and its remarkable findings on ultrasonography, mammography, and magnetic resonance imaging (MRI).…”