Pathologica 4-07.pdf - Pacini Editore

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tors may play a more important role in the angiogenesis of
the latter.
References
1 Nakagawa T, et al. Anticancer Res 1999;19:2963-8.
2 Ko SY, et al. Int J Cancer 2004;111:727-32.
Neuroendocrine small cell carcinoma of the
breast: a report of two cases with
immunohistochemical features
G. Perrone, M. Zagami, S. Morini * , G. Gullotta, V. Altomare
** , C. Rabitti
Anatomia Patologica, * Anatomia Umana, ** Unità di Senologia,
Policlinico Universitario Campus Bio-Medico di Roma,
Roma, Italia
Introduction. Small cell carcinoma, although most commonly
encountered in the lung, can occur in many extrapulmonary
sites, including the salivary glands, upper respiratory mucosa,
intestinal tract, pancreas, urinary tract, and other organs. Small
cell neuroendocrine carcinoma (SCNC) a of the breast is a rare
tumour with less than 30 cases reported in the literature.
Case 1. A 96 year old woman presented with a mass in her
right breast. Radiological and clinical examination failed to reveal
tumour elsewhere in the body. She had a breast cancer excision,
which was diagnosed as SCNC. The size of the tumour
was 3,5 cm. Axillary clearance was not performed. Immunohistochemical
study showed positivity for NSE and MNF116
cytokeratin (dot-like pattern) while negative for chromogranin,
synaptophysin, oestrogen receptor, progesterone receptor, p53,
HER2. Ki-67 was positive in > 40% of cancer cells.
Case 2. A 42 year old woman presented with a mass in her
left breast. Radiological and clinical examination failed to reveal
tumour elsewhere in the body. She had a simple lumpectomy
with axillary dissection. Microscopically, a 3.5 cm SC-
NC with focal squamous differentiation and foci of in situ
ductal component with 26 negative lymph nodes was diagnosed.
In the neuroendocrine small cell component, immunohistochemical
study showed positivity for NSE, chromogranin,
synaptophysin, MNF116 cytokeratin (dot-like pattern),
while negative for HMW-CK. On the other hand, the
squamous component resulted negative for NSE, chromogranin
and synaptophysin while positive for MNF116 cytokeratin
and HMW-CK. Furthermore, oestrogen receptor, progesterone
receptor, HER2 were negative. Ki-67 and P53 were
respectively positive in 98% and 50% of cancer cells.
Conclusion. SCNC is a rare tumour of the breast. The distinction
is particularly important in view of the perceived
more aggressive behaviour 1 . The diagnosis of SCNC in the
breast can usually be supported by detecting immunohistochemical
evidence of neuroendocrine differentiation, however
one of our cases of small cell mammary carcinoma did not
display consistent immunoreactivity for neuroendocrine
markers beyond strong and diffuse staining with NSE. Heterogeneous
immunoreactivity for neuroendocrine markers is
a well-documented observation in small cell carcinomas at
other sites 2 . Demonstrating a neuroendocrine immunoprofile
is supportive but not essential in rendering a diagnosis of
mammary small cell carcinoma.
References
1 Samli B. Arch Pathol Lab Med 2000;124:296-8.
2 Guinee DG. Am J Clin Pathol 1994;102:406-14.
CAV-1 protein expression in lobular breast
neoplasia progression
M. Zagami, G. Perrone, G. Lescarini, V. Altomare * , S.
Morini ** , C. Rabitti
Anatomia Patologica, * Unità di Senologia, ** Anatomia
Umana, Università Campus Bio-Medico di Roma, Italia
Introduction. CAV-1 is the principal structural component
of caveolae domains, which represent a subcompartment of
the plasma membrane. Several lines of evidence suggest that
caveolin-1 functions as a suppressor of cell transformation 1 .
A recent report showed that expression of caveolin-1 was
down-regulated in breast ductal carcinoma cells compared
with the normal breast epithelial cells 2 . To data, no information
exists on neoplastic lobular breast pathology. In the present
study CAV-1 expression was studied in normal lobular
epithelial cells, LIN lesion and in lobular invasive cancer.
Materials and methods. 69 specimens of lobular neoplasm
(35 LIN, 34 invasive cancers) were examined for CAV-1 expression
by immunohistochemistry. CAV-1 was evaluated as
percentage of positively stained cells in a total of at least
1000 tumour cells. Staining for CAV-1 was considered positive
if > 10% of cells were stained.
Results. Immunohistochemical analysis revealed strong fine
granular expression of caveolin-1 concentrated at the surface
membrane and a diffuse cytoplasmic staining pattern in the
normal lobular epithelial cells and surrounding endothelial
cells (used as internal positive control) in all 69 cases. A
strong significant difference (p < 0,0001) was found in terms
of CAV-1 expression between LIN [28/35 (80%)] and invasive
lesions [11/34 (32,3%)]. If CAV-1 expression was considered
within different LIN grades, no significant difference
was found between LIN1 and LIN2 while a significant difference
was found between LIN1 and LIN3 (p = 0,02) and
between LIN2 and LIN3 (p = 0,038). Moreover no significant
difference was found between LIN3 and invasive lesions.
Furthermore, a negative significant correlation was
found between CAV-1 expression and lobular neoplasia grading.
Conclusions. The higher percentage of CAV-1 positive LIN
lesions compared with invasive lobular cancer and the significant
negative correlation between CAV-1 expression and
lobular neoplasia grading are further evidence of the possible
role of CAV-1 in the development of human lobular breast
cancer. Furthermore, our results show that CAV-1 expression
is similar in LIN3 lesions and in invasive lobular carcinoma.
A provocative possible explanation of the latter data is that
LIN3, rather than LIN1 and LIN2 lesions, is a precursor lesion
of invasive lobular carcinoma rather than a simple risk
factor.
References
1 Williams TM. Mol Biol Cell 2003;14:1027-42.
2 Park SS, et al. Histopathology 2005;47:625-30.
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