33 Special Types of Invasive Breast Carcinoma: Diagnostic Criteria ...

the often close morphologic overlap and similar prognosis, it might be more expedient
to refer to these mixed lesions as “invasive tubular/cribriform carcinomas,” rather than
attempt to apply such an arbitrary cutoff point. Tubular and cribriform carcinomas are
likely very closely related, and probably represent different points in the morphologic
spectrum of a single form of well-differentiated invasive breast carcinoma. Although
tubular carcinoma can be diagnosed by FNA (9, 41), excisional biopsy is usually
necessary to clearly establish the diagnosis.
The prognosis for both of these well-differentiated breast carcinomas is equivalent. A
review of seven studies, including 341 women with pure tubular carcinoma, found that
~3.5% had recurrences (10); 6 in the same breast after simple excision and 6 after
mastectomey. Three had axilalry node metastastasis, two patients had local recurrence,
3 had systemic metastases, and one patient had persistent carcinoma. Death due to
pure tubular carcinoma is rare (11), but more dire outcomes occur in patients with
mixed tubular and ductal carcinoma (i.e., recurrences have been reported in up to 32%
of patients with mixed tubular and ductal carcinoma and 6% to 28% of these patients
died)(4,5).
Two studies concluded that patients with classic cribriform carcinoma are less likely
to develop axillary lymph node metastases than women with mixed cribriform (6) or
ordinary invasive duct carcinoma (7). No deaths due to classic cribriform carcinoma
occurred in one study of 34 patients with a 10 to 21 year follow-up (6); however, one
patient had recurrence and another died of metastases from a different contralateral
carcinoma. Venable et al. (7) reported a disease-free survival of 100% for 45 patients
with classic cribriform carcinoma who were followed for 1 to 5 years.
Patients with unifocal pure tubular/cribriform carcinoma are candidates for breast
conservation therapy and, possibly, radiation for possible recurrence. Most experts
agree that low axillary dissection should be performed on patients with a
tubular/cribriform carcinoma larger than 1 cm, when invasive lesions are multifocal,
or if there are other indications to suggest axillary node metastases. The average
frequency of axillary lymph node metastases resulting from such lesions is from 9% to
12%, but the reported range is from 6% to 30% (5,11,12). Multifocality, which
occurs in ~20% of patients with pure tubular carcinoma, appears to increase the
incidence of axillary metastases (13). Affected lymph nodes are usually in the low
axilla (level I) and only rarely are more than three involved (11). When present,
metastases in lymph nodes tend to have a tubular growth pattern. Axillary metastases
are uncommon in patients with “pure” tubular carcinoma tumors 1.0 cm or less in
diameter. This led Berger et al. (13) to advise against axillary dissections in such
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