case_images: PMC10422886_01
case_images: Timeline schematic of the patient's disease course. CT (a) and PET-CT (b) scan showing initial anterior mediastinal mass in 2017. Abdominal MRI (c) and PET-CT scan (d) showing metastatic lesion in the liver. Pelvic MRI (e) showing uptake in the sigmoid colon. (f) PET-CT scan showing metastatic lesion in a portocaval lymph node.. CT, computed tomography; PET-CT, positron emission tomography-computed tomography; MRI, magnetic resonance imaging.
case_images: 10.1177_26330040231190661-fig1.jpg
case_images: PMC10422886_01_10.1177_26330040231190661-fig1.jpg
case_images: fig1-26330040231190661
case_images: A subsequent evaluation revealed a 6.6 cm anterior mediastinal mass [Figure 1(a) and (b)], consistent with stage IVB (T3N2M0) poorly differentiated TC with squamous features (Figure 2). Magnetic resonance imaging revealed two lesions in the liver: a 1.4 x 1.3 cm mass in segment 5 and 0.7 x 0.7 cm mass in the caudate lobe [Figure 1(c)]. PET-CT scan showed new uptake in the liver and sigmoid colon [Figure 1(d) and (e)]. Fourteen months after treatment cessation, a surveillance PET-CT showed a hypermetabolic portocaval LN positive for metastatic TC [Figure 1(d)].
case_images: Pathology slides of the anterior mediastinal mass. (a) Low power (100x) Hematoxylin and Eosin (H&E) slide showing a nested poorly differentiated carcinoma with a marked desmoplastic stroma. (b) High power (400x) H&E slide. (c) Immunohistochemistry (IHC) stain of PD-L1 showing 100% expression (100x). (d) IHC stain of cytokeratin AE1.3 confirms carcinoma (200x). (e) IHC stain of CD5 confirms thymic origin (200x). (f) IHC stain of P40 confirms squamous type (200x).
case_images: 10.1177_26330040231190661-fig2.jpg
case_images: PMC10422886_01_10.1177_26330040231190661-fig2.jpg
case_images: fig2-26330040231190661
case_images: A subsequent evaluation revealed a 6.6 cm anterior mediastinal mass [Figure 1(a) and (b)], consistent with stage IVB (T3N2M0) poorly differentiated TC with squamous features (Figure 2).