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

survival rate than is usually reported for cytologically high-grade metaplastic breast
carcinomas (2). Although large tumors are more likely to recur, other histologic
features such as grade, cellularity, mitotic activity, differentiation of the carcinoma,
presence of squamous epithelium, and degree of inflammation do not correlate with
outcome (2). More specifically, Wargotz and Norris reported that "seven (41%) of the
17 neoplasms that lacked intraductal carcinoma or overt infiltrating ductal carcinoma
had been diagnosed originally as fasciitis, fibromatosis, or low-grade mesenchymal
tumor and had received excisional biopsy. Five (71%) of these “low-grade” appearing
tumors recurred locally and more extensive surgical therapy was performed, but two
of the patients subsequently died from tumor. It is important that four of the other ten
patients in this group also eventually died from tumor. Twelve patients died of causes
unrelated to their breast cancer. The cumulative 5-year survival rate for 100 patients
with spindle-cell carcinoma, adjusting for patients who died from other causes, was
64%." Also, more recent studies of spindle-cell (sarcomatoid) carcinoma of the breast
have found them to be highly aggressive neoplasms with a high rate of extranodal
metastases (including the cytologically bland fasciitis-like variant) – although they
may have a significantly lower rate of nodal metastases than conventional ductal and
lobular carcinomas (30).
In contrast, some have suggested that the cytologically bland fasciitis or fibromatosislike
spindle cell carcinomas are more likely to follow a more favorable course with
local recurrence and rare distant metastases. However, before this can be concluded,
caution is advised. I believe we should be careful about implying they are locally
recurrent–only tumors. Indeed, a recent publication underscores the need for caution
before concluding that the bland spindle-cell breasts are not aggressive. Carter and
coworkers (30) studied spindle cell (sarcomatoid) carcinoma of the breast, a rare
variant of breast cancer that has been classified under the broad rubric of metaplastic
carcinoma. Based on this series, spindle-cell/sarcomatoid carcinoma of the breast is a
highly aggressive neoplasm with a high rate of extranodal metastases. Purely
spindled/sarcomatoid tumors have a significantly lower rate of nodal metastases than
conventional ductal and lobular breast carcinomas. Not surprisingly, large tumors with
high nuclear grade and frequent mitoses were generally (but not always) aggressive.
They also found somewhat surprisingly that even low-grade tumors were capable of
aggressive behavior with metastases and subsequent mortality. Of the 6 low-grade
tumors with follow-up information, 33% (2 of 6) died of metastatic disease, 1 patient
was alive with widespread metastases, and 1 patient was alive with chest wall
involvement and metastases to the axilla. The further observed that this group of
tumors appeared to be more aggressive than conventional ductal carcinomas of similar
size, with an apparent tendency for somewhat earlier systemic metastasis, and that
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