Radiological and Histological Clues in the Diagnosis of Solitary and Synchronous Breast Metastasis From Small Cell Lung Carcinoma

Abstract

Breast metastases from small cell lung carcinoma (SCLC) are extremely rare. Although reports of breast metastases from SCLC exist, only three studies have reported solitary and synchronous breast metastases. Herein, we present a case of SCLC with solitary and synchronous breast metastases. This unusual case highlights the importance of the combined use of radiological and immunohistochemical features to accurately distinguish solitary metastatic SCLC from primary breast carcinoma or metastatic carcinoma of other types of lung cancer. It also emphasizes the importance of the differences between solitary metastatic SCLC and primary breast carcinoma or metastatic carcinoma of other types of lung cancer for the respective prognoses and development of appropriate therapeutic plans.

Keywords: Breast Neoplasms; Neoplasm Metastasis; Small Cell Lung Carcinoma.

Figure 1. Imaging study findings of breast metastasis from small cell lung carcinoma.

(A) Computed tomography scan of the chest shows a hilar mass with heterogeneous enhancement that encased the right middle lobar bronchus and invaded the right main pulmonary vein. (B) Mediolateral mammography of the left breast reveals a round, circumscribed, hyperdense mass without microcalcifications. (C) Ultrasound examination of the left breast shows an oval, circumscribed, parallel-oriented, and complex solid and cystic mass.

Figure 2. Histological features of breast biopsy.

(A) In the lower-power field, a tumor with high cellularity is visible (H&E stain, original magnification: ×100). (B) The tumor cells have scant cytoplasm with round to oval nuclei. Nuclear molding is also evident (H&E stain, original magnification: ×400). The tumor cells show immunoreactivity to (C) CD56 and (D) synaptophysin (original magnification: ×400). H&E = hematoxylin-eosin.