Daiki Takatsuka1, Hiroyuki Ogura2, Yuko Asano2, Akiko Nakamura2, Kei Koizumi2, Norihiko Shiiya2, Satoshi Baba3. 1. First Department of Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka, 431-3192, Japan. d.t.21.arzt@gmail.com. 2. First Department of Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka, 431-3192, Japan. 3. Department of Pathology, Hamamatsu University Hospital, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka, 431-3192, Japan.
Abstract
BACKGROUND: Fibromatosis-like metaplastic carcinoma (FLMCa), classified as a metaplastic carcinoma of the breast, is a very rare type of metaplastic carcinoma. We report a case of FLMCa that was difficult to diagnose. CASE PRESENTATION: The patient was a 56-year-old postmenopausal woman who presented with a left-sided breast mass. A 1.3-cm irregular mass was found in the lower outer quadrant of the left breast on breast ultrasonography. She underwent core needle biopsy and vacuum-assisted biopsy, but the pathological findings only revealed inflammatory cell infiltration and a high level of fibrosis, with no malignant findings. At 3 months follow-up, she underwent a repeat breast ultrasonography, which revealed an increase in the size of the mass to 1.8 cm, and a repeat core needle biopsy, which showed a few spindle cells and squamous cells positive for cytokeratin (CK)5/6 and AE1/AE3, leading to the suspicion of FLMCa. Since the amount of tissue was insufficient to establish a definitive diagnosis, she underwent a lumpectomy. We found low-grade and slightly atypical spindle cells and partly atypical spindle cell carcinoma and squamous cell carcinoma. CK5/6 and α-SMA were positive, thus confirming FLMCa. Because the margins on the edge of the nipple side and anterior side were "ink on tumor", she underwent a mastectomy and sentinel lymph node biopsy. After the surgery, she received adjuvant chemotherapy. At 3 years and 8 months of follow-up, no recurrent or metastatic lesions were identified in her body. CONCLUSIONS: FLMCa should be considered in the differential diagnosis when collagenous fibers are proliferating and malignancy is clinically suspected. Immunohistochemical analysis may be helpful in confirming this diagnosis.
BACKGROUND:Fibromatosis-like metaplastic carcinoma (FLMCa), classified as a metaplastic carcinoma of the breast, is a very rare type of metaplastic carcinoma. We report a case of FLMCa that was difficult to diagnose. CASE PRESENTATION: The patient was a 56-year-old postmenopausal woman who presented with a left-sided breast mass. A 1.3-cm irregular mass was found in the lower outer quadrant of the left breast on breast ultrasonography. She underwent core needle biopsy and vacuum-assisted biopsy, but the pathological findings only revealed inflammatory cell infiltration and a high level of fibrosis, with no malignant findings. At 3 months follow-up, she underwent a repeat breast ultrasonography, which revealed an increase in the size of the mass to 1.8 cm, and a repeat core needle biopsy, which showed a few spindle cells and squamous cells positive for cytokeratin (CK)5/6 and AE1/AE3, leading to the suspicion of FLMCa. Since the amount of tissue was insufficient to establish a definitive diagnosis, she underwent a lumpectomy. We found low-grade and slightly atypical spindle cells and partly atypical spindle cell carcinoma and squamous cell carcinoma. CK5/6 and α-SMA were positive, thus confirming FLMCa. Because the margins on the edge of the nipple side and anterior side were "ink on tumor", she underwent a mastectomy and sentinel lymph node biopsy. After the surgery, she received adjuvant chemotherapy. At 3 years and 8 months of follow-up, no recurrent or metastatic lesions were identified in her body. CONCLUSIONS:FLMCa should be considered in the differential diagnosis when collagenous fibers are proliferating and malignancy is clinically suspected. Immunohistochemical analysis may be helpful in confirming this diagnosis.
Entities:
Keywords:
Breast cancer; Fibromatosis-like metaplastic carcinoma; Metaplastic carcinoma