A 49‐year‐old Caucasian woman was admitted to our hospital because of mass in her right breast. The patient was nulligravida nulliparous. No history was obtained for drug uses such as antihypertensive, antipsychotic, or exogenous estrogen intake. She had no family history of breast cancer. Physical examination revealed a relatively well‐circumscribed, nodular, and firm mass in the upper quadrant of her right breast. Radiologically, hypoechoic mass with ill‐defined borders and 35 mm in largest dimension was determined. Core needle biopsy revealed invasive breast carcinoma. The patient underwent modified radical mastectomy. Macroscopically, an ill‐defined ( 3. 5 cm × 3 cm × 2 cm in size) solid tumor, gray‐white in color with common hemorrhagic areas, was identified. Microscopically, the tumor composed of both malignant epithelial and mesenchymal components [Figure 1a]. The epithelial part showed irregular solid proliferations of tumor cells including common necrotic areas as well as lumen formation [Figure 1b]. Squamous eddies were noted focally [Figure 1c]. Tumor cells showed large eosinophilic cytoplasm in the form of epithelioid, polygonal, and spindle‐shaped and large pleomorphic nucleus with vesicular chromatin distribution and prominent nucleoli. These groups of tumor cells intermingled with a mesenchymal component demonstrating myxoid/myxochondroid features [Figure 1d]. Osteoid formation was noticed focally [Figure 1e]. Interestingly, varying degrees of cystic hypersecretory lesions (CHL) as well as pregnancy‐like hyperplasia (PLH) were determined concomitantly adjacent to invasive tumor [Figure 1f and g]. CHL were identified as cystic hypersecretory hyperplasia (CHH) with or without atypia and an alteration through high‐grade ductal carcinoma in situ (DCIS) with patterns of flat, micropapillary, papillary, or cribriform was noted [Figure 1h, i, and k]. Similarly, PLH was observed in a spectrum as PLH without atypia, PLH with atypia, and adjacent to them as DCIS [Figure 1l and m]. Some of the terminal ductal lobular units showed both features of PLH and CHL, concomitantly. Microcalcification associated with these lesions was not detected. The tissues sampled away from the tumor showed only fibrocystic changes such as stromal fibrosis, adenosis, dilated ducts, and apocrine metaplasia. The invasive tumor showed positive immunostaining, both for pancytokeratin and vimentin [Figure 2a and b]; negative staining for estrogen and progesterone hormone receptors and CerbB2 (triple negative). No lymphovascular and perineural invasion was determined. Axillary lymph nodes were free of tumor. The tumor stage was T2N0M0. Chemotherapy was planned for the treatment. After four cycles of cyclophosphamide and doxorubicin, pleural tumor metastasis was detected. Therefore, cisplatin and gemcitabine were added. However, the patient died 23 months after her initial operation due to brain metastasis.