Isolated splenic metastasis from a thymic carcinoma: A case report

Abstract

Thymic carcinomas are rare tumors that arise in the anterior mediastinum. Most of these malignancies develop local metastases limited in the thorax. Splenic metastases from thymic carcinomas are extremely rare. Here we report a case of isolated splenic metastasis from a 38-year-old female patient with Stage IV thymic carcinoma, who was treated with chemoradiotherapy. At twenty-2 months follow-up, the patient was found to have an isolated spleen metastasis, which was treated by Cyberknife with a reduced size of the metastasis, representing a partial response. Although splenic metastasis is a rare phenomenon, physicians need to be aware of the possibility of such metastases.

Keywords: Chemotherapy; PET/CT; SBRT; oligometastasis; radiation; spleen metastasis; thymic carcinoma.

Figure 1.

(A) Hematoxylin-Eosin staining of the thymic mass showed tumor cells grew diffusely. Immunohistochemical analysis demonstrated the tumor cells were strongly positive for (B) P63, (C) cytokeratins 5/6, immunostaining revealed negative for (D) CD56, (E) synaptophysin and (F) NapsinA respectively.

Figure 2.

Abdominal computed tomography (CT) scan revealed a moderate contrast enhanced lesion that measured 4.5 cm × 3.5 cm in the spleen (A), which was confirmed by fluorodeoxyglucose positron emission tomography (PET/CT), with the SUVmax of 30.67 (B).

Figure 3.

Chest CT and PET/CT showed the thymic mass was stable, which was not enhanced in chest contrast enhanced CT (A) and seen in PET/CT with a SUVmax of 1.8 (B).

Figure 4.

Abdominal CT after radiotherapy: The patient was treated with Cyberknife for her spleen lesion. Abdominal CT showed that the spleen metastasis reduced to 2.6 cm × 3.5 cm at one month follow up.