Congresso
Nazionale
SIAPEC
7 – 9 Settembre
2009
Firenze
Pure type mucinous carcinoma of the
breast with neuroendocrine
differentiation: a case report and
short review of literature
A. D’Amuri, F. Floccari, L. Aiello, A. T. Pede, S. A. Senatore
U.O.C. Anatomia Patologica Ospedale “S. Cuore di Gesù” P.O. Gallipoli
ASL/LECCE
INTRODUCTION
 Mucinous carcinoma (MC) is a special type of invasive
breast neoplasm grouped into pure and mixed types: the
former contains only tumour with the typical mucinous
carcinoma morphology; the latter is mixed with
conventional infiltrating ductal carcinoma.
 Some authors subdivided MC components on the basis
of mucin content, epithelial growth pattern and associated
figures in type A (tumors containing 60-90% of mucin) and
type B (tumors containing 33-75% of mucin).
 A large proportion of MC show a neuroendocrine
differentiation and its significance is still unclear.
INTRODUCTION
 MC with or without neuroendocrine differentiation occurs
in the elderly and the proportion of postmenopausal
patients is high.
 The symptom and sign is palpable mass and bloody
nipple discharge.
 The evaluation of MC outcome is difficult because of the
short follow-up period due to the old age of the patients
who may die of other unrelated causes.
 The majority of patients do not show local recurrences or
distant metastasis. Lymph nodes metastasis are rare.
CASE REPORT
 An 82 year old woman with no significant medical history
showed a palpable mass in her retro-areolar right breast.
 The patient underwent radical mastectomy and right
axillary lymph nodes dissection.
SURGICAL FEATURES
 Grossly the right breast showed nipple retraction,
discromic skin with a normal areolar gland. The remaining
breast parenchima had a lipomatous aspect.
 In the retro-areolar region a 4x4x2cm nodular lesion was
observed.
 The nodule had a hard-elastic consistency, a yellowish
white appearance with interspersed brownish and
gelatinous areas.
MATERIALS & METHODS
 Once removed specimens were fixed in 10% buffered
formalin and paraffin embedded. 5mm serial sections were
obtained and routinely stained with haematoxylin-eosin
(H/E) and histochemically evaluated with Grimelius.
 Immunohistochemical studies were performed for
Neuron Specific Enolase (NSE), Chromogranin (CGA),
Synaptophysin (SYN), Neurofilament (NF), estrogen (ER)
and progesteron (PgR) receptors, c-erbB-2 and Ki-67
(MIB-1).
MICROSCOPICAL FINDINGS
 Microscopically we observed small clusters of tumor
cells with abundant extracellular mucin accumulation
(65%).
 The cells were small to medium sized with a spindle
shape. The nuclei appeared uniform and the cytoplasm
eosinophilic and finely granular.
 The 19 axillary lymph nodes were found all negative for
metastasis.
MICROSCOPICAL FINDINGS
 Immunohistochemical stains for NSE, CGA, SYN and NF
were positive with a marked histochemical expression of
Grimelius (argyrophilic cells). The tumor was positive for
estrogen (90%) and progesteron (80%) receptors,
incompletely positive for c-erbB-2 (15%) with a low Ki-67
proliferative index (10%).
 A diagnosis of pure type mucinous carcinoma
(hypercellular variant) of the breast with neuroendocrine
differentiation was performed.
H&E
H&E
Grimelius
NSE
SYN
CGA
Estrogen receptors
Progesteron receptors
DISCUSSION
 MC of the breast is a good prognostic type malignancy
which may occur in elderly patients.
 MC is most commonly associated with neuroendocrine
differentiation.
 Neuroendocrine differentiation has long been described
but its significance is still unknown.
 The criteria for diagnosing neuroendocrine differentiation
is based on immunohistochemistry, histochemistry with
Grimelius for argyrophil reaction and electron microscopy
evaluation.
DISCUSSION
 As reported in literature some authors consider the
expression of the neuroendocrine markers namely CGA,
SYN and NSE definitive.
 Other authors used two out of three positivity as
diagnostic criteria.
 It is also associated with higher expression of estrogen
and progesteron receptors and lower c-erbB-2 oncoprotein
expression and with a low Ki-67 proliferative index.
 Lymph nodes metastasis are uncommon.
DISCUSSION
 In our case report the clinicopathological features were
similar to those reported in literature and included the
presence of clusters of tumor cells of moderate-grade with
abundant extracellular mucin accumulation.
 Our histochemical study (positive for Grimelius) and
immunohistochemical findings (positive for CGA, SYN,
NSE, NF; higher expression of ER and PgR receptors and
lower expression of Ki-67 and c-erbB-2) strongly support
the diagnosis.
 This type of tumour occurred in an old patient and the
axillary lymph nodes were found all negative for metastasis
as reported in previous studies.
REFERENCES
 Kato N. et al. Mucinous carcinoma of the breast: A multifaceted study
with special reference to histogenesis and neuroendocrine
differentiation. Pathol Int 1999; 49: 947-955
 Nakagawa H. et al. Mucinous carcinoma of the breast with
neuroendocrine differentiation. Pathol Int 2000; 50: 644-648
 David O. et al. Diffuse neuroendocrine differentiation in a
morphologically composite mammary infiltrating ductal carcinoma. A
case report and review of the literature. Arch Pathol Lab Med 2003; 127:
e131-e134
 Tse GMK. et al. Neuroendocrine differentiation in pure type mammary
mucinous carcinoma is associated with favorable histologic and
immunohistochemical parameters. Mod Pathol 2004; 17: 568-572