Baylor University Medical Center Proceedings April 2017 - 200

Primary small-cell carcinoma of the breast
Benjamin Raber, MD, Tuoc Dao, MD, Evan Howard, MD, and Arthur Bredeweg, DO

Early diagnosis of rare breast cancers is expected to occur more frequently as screening compliance improves and diagnostic modalities
become more sensitive. Well-defined treatment algorithms exist for the
management of ductal and lobular carcinomas; however, less information
is available to guide the treatment of atypical breast cancers. This case
report describes a 38-year-old African American woman with primary
small cell carcinoma of the breast and her treatment.

xtrapulmonary small cell cancer comprises only 5% of all
small cell carcinomas (1), and small cell carcinoma of the
breast comprises <1% of all breast cancers (2). For the
minority of small cell cancers that are extrapulmonary,
treatment guidelines and prognostic risk factors are not well
deﬁned. Here we report a case of primary small cell carcinoma
of the breast; treatment involved multidisciplinary application
of principles learned in the treatment of small cell lung cancer
(SCLC) as well as other extrapulmonary small cell carcinomas.
CASE STUDY
A 38-year-old African American woman with no signiﬁcant
past medical history presented to her gynecologist complaining
of a new-onset palpable mass in her left breast. An ultrasound
demonstrated a 2 × 1.2 × 1.7 cm hypoechoic oval mass with
irregular microlobulated margins (Figure 1). Ultrasound-guided
core needle biopsy was performed. In the biopsy specimen, normal breast lobular architecture was visible just adjacent to the
tumor, which demonstrated a high-grade malignant neoplasm
with lymphovascular invasion. The tumor displayed some of
the classic features of small cell carcinoma. The immunostains
for pancytokeratin, chromogranin, and synaptophysin were
positive, consistent with the neuroendocrine nature of small
cell carcinoma (Figure 2). Pathologic interpretation supported
the diagnosis of an epithelial lesion with at least some neuroendocrine diﬀerentiation consistent with small cell carcinoma
of the breast.
The patient was referred to breast surgical oncology. On
exam, the known breast mass was palpated, as well as a few
abnormally large left axillary lymph nodes, concerning for
nodal spread. Before deﬁnitive operative intervention, given
the patient's young age of diagnosis and aggressive histology
200

Figure 1. Sonographic image of the palpable area of concern in the 1 o'clock
position of the left breast shows the dominant 2 cm hypoechoic mass with two
smaller adjacent masses.

Figure 2. Core needle biopsy with positive chromogranin staining.

of the tumor, genetic testing and a staging positron emission
tomography (PET) scan were performed. Genetic testing was
negative for BRCA, and no additional cancer gene mutations
were tested. PET scan demonstrated 3 hypermetabolic masses
in the upper outer quadrant of the left breast, consistent with
multifocal malignancy. Additionally, there was hypermetabolic
From the Departments of Surgery (Raber, Dao), Radiology (Howard), and Pathology
(Bredeweg), Baylor University Medical Center at Dallas.
Corresponding author: Benjamin Raber, MD, 3132 Oliver Avenue, Dallas, TX
75205 (e-mail: Benjamin.Raber@BSWHealth.org).
Proc (Bayl Univ Med Cent) 2017;30(2):200-202

Table of Contents for the Digital Edition of Baylor University Medical Center Proceedings April 2017