Micropapillary carcinoma of the breast

Definition

Epidemiology

About 2.5% of all breast carcinomas are of micropapillary type1. Patients are adult, with a mean age of about 50 years1.

Histopathology

There are infiltrating micropapillae without a fibrovascular core: the micropapillae are surrounded by clear spaces2. These intermix with tubulo-alveolar clusters separated by fibrocollagenous stroma. Psammoma bodies vary from rare4 to common7. A minority of cases are combined with a ductal, neuroendocrine or mucinous component, the cells within the mucin also having a micropapillary configuration. Lymphovascular invasion is common, with a high rate of nodal metastases. Skin involvement is common7.

Metastases and recurrences retain the micropapillary architecture2,8.

Immunohistochemistry

	micropapillary carcinoma	invasive ductal carcinoma NOS
Oestrogen receptors	21/311, 24/333, 68/754, 71%5	23/601
Progesterone receptors	19/311, 15/333, 52/744	19/601
bcl-2	23/333
p53	15/311, 6/87	22/601
c-erbB-2	17/311, 12/333	31/601
Ki67 proliferation index	mean = 26% (31 cases)1	mean = 16% (60 cases)1
HER-2/neu protein	13/224
EMA	preferentially stains the outside of the micropapillae10

Cytogenetics

Loss of the short arm of chromosomes 8 is common9.

Differential diagnosis

Other breast carcinomas:

invasive papillary carcinoma: there is a true papillary structure and low grade cytology.
colloid carcinoma: mucin secretion is a component of some micropapillary carcinomas. A thorough search must be made to exclude any micropapillary component.

Metastases:

ovarian micropapillary serous carcinoma
micropapillary transitional cell carcinoma of bladder
micropapillary carcinoma of the colon: CK7-/CK20-.
micropapillary adenocarcinoma of lung

Prognosis

The rates of local recurrence, distant metastases and death from disease have all been reported to be higher than for ductal carcinoma1. However, stage for stage, the prognosis may be similar to that of ductal carcinoma6.

References

1 Zekioglu, O., Y. Erhan, et al. (2004). "Invasive micropapillary carcinoma of the breast: high incidence of lymph node metastasis with extranodal extension and its immunohistochemical profile compared with invasive ductal carcinoma." Histopathology 44(1): 18-23.

2 Siriaunkgul, S. and F. A. Tavassoli (1993). "Invasive micropapillary carcinoma of the breast." Mod Pathol 6(6): 660-2.

3 Luna-More, S., F. de los Santos, et al. (1996). "Estrogen and progesterone receptors, c-erbB-2, p53, and Bcl-2 in thirty-three invasive micropapillary breast carcinomas." Pathol Res Pract 192(1): 27-32.

4 Walsh, M. M. and I. J. Bleiweiss (2001). "Invasive micropapillary carcinoma of the breast: eighty cases of an underrecognized entity." Hum Pathol 32(6): 583-9.

5 Nassar, H., T. Wallis, et al. (2001). "Clinicopathologic analysis of invasive micropapillary differentiation in breast carcinoma." Mod Pathol 14(9): 836-41.

6 Paterakos, M., W. G. Watkin, et al. (1999). "Invasive micropapillary carcinoma of the breast: a prognostic study." Hum Pathol 30(12): 1459-63.

7 Middleton, L. P., F. Tressera, et al. (1999). "Infiltrating micropapillary carcinoma of the breast." Mod Pathol 12(5): 499-504.

8 Tresserra, F., P. J. Grases, et al. (1999). "Invasive micropapillary carcinoma. Distinct features of a poorly recognized variant of breast carcinoma." Eur J Gynaecol Oncol 20(3): 205-8.

9 Thor, A. D., C. Eng, et al. (2002). "Invasive micropapillary carcinoma of the breast is associated with chromosome 8 abnormalities detected by comparative genomic hybridization." Hum Pathol 33(6): 628-31.

10 Putti TC, Pinder SE, Elston CW, et al. Breast pathology practice: most common problems in a consultation service. Histopathology 2005; 47:445-57

This page last revised 15.12.2005.