Small....but lethal

History

• P/C: 44 yr female, presented with symptoms left breast

Painless lump Not sure of the duration No skin changes

• HOPC & Past history

No nipple discharge, no previous h/o similar complaint Smoker 20 cig/day, non-diabetic 3 children No previous h/o benign breast disease

History

• Family History

Mother had breast cancer at the age of 76 (now well) Paternal aunt had breast cancer at the age of 52 (now well)

Clinical Examination

• Examination finding

Lump on the left upper quadrant Size 10 cms Mobile Non-tender No skin changes, no nipple discharge no lymphadenopathy

TBC

• Referral to triple assessment clinic• Clinical score: 4

Mammogram Ultrasound Core biopsy

Ultrasound

Mammogram

Biopsy

Clinical core biopsy x 4 of the left breast lump

Histopathological diagnosis

x5 x20

Core biopsy

T

N

ImmunohistochemistrySynaptophysin CLA

Immunohistochemistry

• Positive for CD56 and synaptophysin• Negative for CK7 and CK20• ER,PR and HER-2 negative

Further investigations

• CT • Bronchoscopy

Oat cell carcinoma in breast

• Extrapulmonary small-cell neuroendocrine carcinomas account for 2.5% - 5% of all small-cell neuroendocrine tumours

• Primary neuroendocrine carcinoma of the breast are a group of neoplasms with morphological features similar to those of neuroendocrine tumours of the gastrointestinal tract and lung.

• Primary small cell neuroendocrine carcinoma of the breast (SCNC) is one of the most uncommon variants

Incidence

• Most cases are found in women• Age incidence 40-70 years

Diagnosis

• Exclusion of an extra-mammary primary site• Demonstration of an in-situ component within the

breast histopathologically

Histopathology

• The morphological and immunohistochemical patterns of this tumour are very similar to its pulmonary counterpart

• Some believe that SCNC is a distinct type of breast carcinoma different from the usual types of carcinoma

• It is important that the in situ ductal component is truly a precursor lesion of small-cell neuroendocrine carcinoma and supports a primary breast origin

Immunohistochemical pattern

• Expression of neuroendocrine markers (CAM 5.2, CK7, neuron specific enolase NSE, PGP9.5, chromogranin and synaptophysin) strongly supports the diagnosis

• However this expression is inconsistent

Hormone receptor expression

• Positive expression of ER and PR has been reported in lungs and other sites

• Their expression in SCNC is not proof of mammary origin

• Varied expression in literature of primary breast SCNC

Treatment

• No standard treatment due to its rarity• Surgery and adjuvant chemoradiotherapy is

the mainstay

Clinical outcome

• Controversial due to the lack of differentiation between primary neuroendocrine tumours and usual carcinoma with foci of neuroendocrine cells

• Most SCNC show poor prognosis• Size is an important prognostic factor• Prognosis may not be as poor as originally thought

Summary

• Primary small cell neuroendocrine carcinoma of the breast (SCNC) is one of the most uncommon variants

• The morphological and immunohistochemical patterns of this tumour are similar to its pulmonary counterpart

• Size is a very important prognostic factor in this tumour• The prognosis may not be as poor as previously thought,

particularly for early stage disease• Early detection and multimodality approach like surgery,

chemotherapy and radiotherapy should be used