Fine-needle aspiration cytology of extra mammary metastatic lesions in the breast: A retrospective study of 36 cases diagnosed during 18 years.
BACKGROUND
Metastatic tumors in the breast require treatment according to origin and type of tumor. It is important to recognize these lesions in fine-needle aspiration cytology (FNAC) in order to avoid unnecessary mastectomy or non-relevant chemotherapy. The aim of this study was to evaluate the cytological features of metastatic tumors and possible criteria that could alert us as to the possibility of a metastasis from an extra mammary malignancy.


METHODS
The material included 36 confirmed or suspected metastases in the breast registered in the pathology files at Oslo University Hospital, Ulleval, during 1990-2007. There were a total of 6,325 cases of malignant breast FNAC, representing 30 men and 6,295 women. Smears were evaluated for the amount of material, presence or absence of myoepithelial cells, microcalcifications, mitoses and necrotic material. All carcinomas were graded.


RESULTS
There were seven men (7/30 = 23.3%) and 29 women (29/6,295 = 0.46%). The primary tumor was known in 22 cases (22/36 = 61.1%). No other primary tumor was known and metastatic lesion was not initially suspected in 14 cases (14/36 = 38.9%). The most common origin was lung (15/36 = 41.7%). In five cases (5/36 = 13.9%), the origin remained uncertain.


CONCLUSIONS
Metastases from extra mammary sites are (relatively) common in males (23.3%). In women, metastatic lesions are rare (0.46%). A large proportion of them (88%) are high-grade adenocarcinomas and poorly differentiated carcinomas that may resemble grade 3 ductal carcinomas. Unusual clinical and/or radiological presentation in combination with high-grade malignant cells should alert us to consider the possibility of a metastasis.
Sauer
Torill
T
Department of Pathology, Faculty Division of Clinical Medicine, Oslo University Hospital, Ulleval, N-0407 Oslo, Norway.
AJR Am J Roentgenol. 1983 Oct;141(4):685-90
6604418
Radiology. 1982 Jul;144(2):309-12
7089284
AJR Am J Roentgenol. 1999 Feb;172(2):343-8
9930779
Arch Pathol Lab Med. 1999 Dec;123(12):1208-18
10583925
Cancer. 1998 Jun 25;84(3):160-2
9678730
Cytojournal. 2005 Sep 20;2:17
16174298
Cancer. 2001 Nov 1;92(9):2259-66
11745279
Radiol Clin North Am. 1982 Sep;20(3):561-8
7111707
Semin Ultrasound CT MR. 2000 Oct;21(5):375-94
11071618
Acta Cytol. 2002 Mar-Apr;46(2):377-85
11917589
Cytopathology. 2003 Aug;14(4):191-4
12873311
Am J Clin Pathol. 1989 Jul;92(1):27-35
2750705
Am J Clin Pathol. 1997 Feb;107(2):177-86
9024066
Diagn Cytopathol. 2005 Apr;32(4):193-7
15754368
Eur J Cancer. 1996 Mar;32A(3):512-7
8814700
J Surg Oncol. 1991 Oct;48(2):112-6
1921396
Ann Oncol. 2008 Apr;19(4):682-7
18048381
Cytopathology. 2009 Jun;20(3):176-82
18373697
J Clin Pathol. 1997 Jan;50(1):30-2
9059352
Eur J Gynaecol Oncol. 2005;26(5):547-50
16285577
Lancet. 1994 Apr 16;343(8903):947-9
7909010
Acta Cytol. 2005 Jul-Aug;49(4):445-8
16124178
Acta Cytol. 1987 May-Jun;31(3):291-300
3473862
Diagn Cytopathol. 1996 Jul;15(1):1-6
8807244