Keywords: Octreoscan; neuroendocrine carcinoma of breast
The term, neuroendocrine differentiated breast
cancers, describes a subset of tumors with neuroendocrine
morphology that diffusely express neuroendocrine
markers in more than 50% of cells,
with frequently expressed estrogen and progesterone
receptors, and the frequent coexistence of
mucinous and apocrine differentiation. These tumors
often occur in elderly patients and often have low levels of aggressiveness. Clinical prognosis of
these patients is generally based on pathology reviews
or case reports.[
Wade et al. described the first neuroendocrine
carcinoma of the breast in 1983 and since then all
published cases number less than 30, all presenting
with a lump in the breast as the first sign.
We report a case of neuroendocrine carcinoma
of the breast that presented first with skin metastases.
Mammography and sonography performed as part of the systemic evaluation revealed a 6 mm solid lesion in the upper-outer quadrant of the right breast, which was categorized as ACR BIRADS 4, and axillary lymphadenopathy (18 × 9 mm). A tru-cut biopsy was performed and immunohistochemical evaluation showed a solitary type neuroendocrine carcinoma with both in situ and invasive components of nuclear grade II and histological grade III, and with diffuse positive staining for synaptophysin, focal positive staining for chromogranin (20%), and CD56 negative results.
The estrogen receptor was positive in 80% (NeoMarkers clone SP1), progesterone receptor in 60% (NeoMarkers clone SP1), and there was no overexpression of Her2/neu (Novo Castra 1A6).
The tru-cut biopsy from the breast and punch biopsy from the skin lesions were compared. Although the receptor evaluations of the skin lesions were negative for chromogranin A and synaptophysin, they were considered metastases because of cellular immunohistochemical similarities. The negativity of the receptors was considered to be due to the differentiation in metastatic cells or to the insufficiency of the material for immunohistochemical evaluation.
As a part of the patient's clinical evaluation octreotide
scintigraphy was performed. Octreotide
scintigraphy showed increased activity on the thorax,
belly, and side of the hip. In particular, the increased
activity of the regions with the skin lesions
supported the data that the lesions were metastases
of neuroendocrine carcinoma (Fig.
First-line hormonotherapy with letrozole, to inhibit
the estrogen receptor, together with monthly
intramuscular injection of long-acting octreotide
(Sandostatin LAR 30 mg, Novartis), for the skin
lesions, were initiated. Two months later the skin
lesions paled (Fig.
Studies on neuroendocrine carcinoma of breast
show diverse results on the prognostic factors. Importance
of histological grading were proved in
Sapino's study,[
There are no guidelines and little experience reported
concerning the treatment of neuroendocrine
carcinoma of the breast. Most publications are
based on gastrointestinal neuroendocrine tumors.[
Somatostatin receptors (SSTRs) can be found in
breast cancer cells, making the use of somatostatin
analogs possible.[
Systemic chemotherapy is not planned until
progression occurs. Interferon treatment is very
complicated in neuroendocrine tumors and has no
significant effect on survival.[
Additional studies on neuroendocrine carcinoma
of the breast are necessary to further clarify
its biological behavior and to define an appropriate
treatment protocol. The presented case highlighted
various aspects of neuroendocrine carcinoma
based on its presentation, diagnosis, and treatment.