FNA diagnosis of retroperitoneal leiomyosarcoma metastasizing to the breast

Abstract

Fine-needle aspiration (FNA) biopsy is one of the first-line investigations in any breast lump, and hence cytomorphological recognition of nonmammary metastatic tumors to the breast and their distinction from primary tumors is important. Breast metastasis from extra-mammary malignancy is rare, constituting 2% of breast tumors; even rarer are metastatic leiomyosarcomas. Our patient presented with a breast lump 2 years after operative removal of a retroperitoneal leiomyosarcoma. The breast lump was confirmed to be a metastasis from the earlier primary. Herein, we report the first case of a retroperitoneal leiomyosarcoma metastatic to the breast diagnosed by Fine Needle Aspiration.

Uterine leiomyosarcoma metastasizing to multiple sites: a rare presentation

“…3,6 The cytomorphologic features described in leiomyosarcoma and well visualised in our case are cellular smears composed of tissue fragments, clusters and fascicles of cohesive tumor cells. [7][8][9][10] Elongated nuclei with blunt ends and a vague "C" shape containing small amount of wispy cytoplasm with bipolar cytoplasmic processes may be appreciated. Stripped atypical nuclei may be seen in the background.…”

“…Mitotic figures and necrosis when present indicate malignancy. 10 Leiomyosarcoma can have varied cell morphologies. Intranuclear cytoplasmic invaginations have been reported although these were absent in the present case.…”

Mystery of bilateral breast masses

“…is rarer; 4,6 it is usually low-grade and should be distinguished from leiomyoma. 6 The average interval for occurrence of non-breast tumour metastasis to the breast is approximately 2 years.…”

“…is rarer; 4,6 it is usually low-grade and should be distinguished from leiomyoma. 6 The average interval for occurrence of non-breast tumour metastasis to the breast is approximately 2 years. 5,6 Our patient presented primarily with metastatic breast masses rather than with a primary tumour in the uterus.…”

“…6 The average interval for occurrence of non-breast tumour metastasis to the breast is approximately 2 years. 5,6 Our patient presented primarily with metastatic breast masses rather than with a primary tumour in the uterus. In 85% of patients, metastatic leiomyosarcoma presents as a solitary breast lump and only 15% as bilateral or multiple lumps as in our case.…”