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

cases. In this small tubular carcinoma group there were no axillary metastases in 14
patients; “pure” tubular carcinoma was defined as exclusively tubular differentiation
with or without concomitant DCIS. But, this practice remains controversial; and, in
contrast, Elson et al. (14) found metastatic tubular carcinoma in axillary lymph nodes
in 4 (29%) of 14 patients who had had axillary dissections, three of whom had a
primary tumor 1.0 cm or less in diameter. But in the latter series the tubular carcinoma
had to have 75% or more of the classic tubular pattern to qualify. In another study of
50 patients with tubular carcinoma, Winchester et al. (15) noted a 20% incidence of
axillary nodal metastases that could not be predicted by any features displayed by the
primary tumors.
The average frequency of axillary lymph node metastases in patients with “mixed”
tubular and ductal carcinomas is 34% (12). Because of these reports, I believe it is best
to require that 90% or more of the tumor be of the classic invasive tubular pattern
before a diagnosis of “pure” tubular carcinoma can be made, and the closer to 100%
the better. Invasive cribriform carcinoma, even of “pure” variety, appears to
metastasize more frequently to axillary lymph nodes (i.e., ~40% in one series)(7).
In view of the extremely favorable prognosis of tubular/cribriform carcinoma, there is
little evidence that systemic adjuvant therapy would prove beneficial, except possibly
for women with axillary metastases or if there is also a less well-differentiated carcinoma
in the ipsilateral or contralateral breast. Patients with mixed tubular/ductal or
mixed cribriform/ductal carcinomas should receive treatment appropriate for an
infiltrating duct carcinoma of the grade of the non-tubular component as determined
by tumor size and stage.
Clinicopathologic features: Tubular carcinomas are either incidental findings or
discovered as small, stellate mass lesions. The gross appearance is similar to that of
benign lesions such as sclerosing papillary lesions (aka, "radial scar") (16). Invasive
cribriform carcinomas can present in a similar fashion, but more often form firm mass
lesions with no distinctive features. Both tumor types, including the mixed forms, may
be multifocal in a significant number of patients (i.e., ~20%) (13). About 8% of
invasive carcinomas 1 cm or less in diameter are tubular carcinomas (17). Most
tubular carcinomas are 2 cm or less in diameter, but some as large as 4 cm have been
reported (5,11,18). This tumor is more common in older patients but the age at
diagnosis is ranging from 24 to 92 years (11,18,19). For invasive cribriform
carcinoma, at least one male and 113 female patients (ranging in age from 19 to 86
years) have been described (6,7,20). In my experience, when studied by immunohistochemistry,
both tubular and cribriform carcinomas have always been hormone
46