360
Chapter 11
FIG. 11.36.
DCIS, spindle cell.
A:
The carcinoma cells have spindle-shaped nuclei with traces of
palisading.
B:
Rosette-like microlumens are present.
C:
Spindle cell carcinoma with a central fibro-
vascular stromal core. This focus was part of a complex solid papillary carcinoma with an extensive
spindle cell component.
D:
Spindle cell DCIS with palisading epithelial cells.
microinvasion when DCIS inhabits SA (Fig. 11.42). In a study
of 24 cases of DCIS involving SA, Moritani et al.
140
found that
most DCIS that only involved SA were “non-high-grade,”
whereas DCIS not confined to SA was more often high grade.
Nerves may be incorporated in SA when no carcinoma
is present.
141
The presence of this phenomenon when there
is DCIS in the adenosis is not indicative of invasion. Neu-
ral entrapment has also been observed in areas of sclerosing
papillary DCIS not associated with SA.
142
DCIS has been found to arise near and in
radial scleros-
ing lesions
, so-called radial scars (Figs. 11.43 and 11.44). The
presence of an underlying radial sclerosing lesion (RSL) is
indicated by the overall configuration of the lesion and the
presence of benign proliferative foci such as duct hyperpla-
sia, cysts, SA, and apocrine metaplasia. DCIS with a stellate
growth pattern can present as a RSL(Fig. 11.45). Incomplete
samples of radical scar lesions obtained in needle core biopsy
specimens are difficult to assess for DCIS or for invasion, and
they are likely to be reported as atypical duct hyperplasia.
A diagnosis of radial scar without atypical changes based
on a partially sampled lesion on a needle core biopsy does
not preclude the finding of carcinoma in the subsequent
excision. In a study of 49 cases of radial scar (all without
associated atypical epithelial proliferation) that had been di-
agnosed on needle core biopsy, Bianchi et al.
143
found three
cases of DCIS (and one of invasive lobular carcinoma) in the
subsequently performed excisional biopsy. However, Reset-
kova et al.
144
reported no instances of “upgrade” to invasive
or
in situ
carcinoma in a study of 19 radial scars diagnosed
on needle core biopsy that underwent subsequent excision
of the lesion. Another 61 patients with a diagnosis of radial
scar on needle core biopsy were followed clinically and ra-
diologically without apparent progression of disease. The
authors concluded that ample sampling with larger (11G
or 9G) needles and radiologic correlation could obviate the
need for excision in radial scars diagnosed on needle core
biopsy.
144
Concurrent intraductal and in situ lobular carcinomas
are present when there are separate foci of carcinoma with
these histologic features in the breast. This is illustrated by
instances in which the lobular lesion with the classical small
cell phenotype of lobular carcinoma is limited to TDLUs
