case_images: PMC11263088_01
case_images: PMC11263088_02
case_images: PMC11263088_03
case_images: (A) Upon Hospital Admission.   Imaging revealed a lobulated shadow in the right lower lung field, measuring approximately 3.6 cm x 4.4 cm, with cavitation observed within. (B) After Preoperative Chemotherapy (Before Right Lung Lobectomy).   Imaging showed a reduction in the right lower lung mass to 2.0 cm x 1.8 cm, now presenting as a cavitary lesion. (C) One Month Post-Right Lung Lobectomy.   Imaging indicated postoperative changes in the right lung without any abnormal density. (D) Three Months Post-Right Lung Lobectomy.   Imaging showed postoperative changes in the right lung with no abnormal density observed. (E) Six Months Post-Right Lung Lobectomy.   Imaging demonstrated postoperative changes in the right lung with no abnormal density noted. (F) Five Years Post-Right Lung Lobectomy.   Imaging revealed postoperative changes in the right lung, with no abnormal density detected.
case_images: fonc-14-1361380-g001.jpg
case_images: PMC11263088_03_fonc-14-1361380-g001.jpg
case_images: f1
case_images: A contrast-enhanced spiral CT scan of the chest performed at our hospital indicated a malignant tumor in the lower right lung, with metastasis to the mediastinum and lymph nodes ( Figure 1 ). Post-treatment follow-up with contrast-enhanced spiral chest CT indicated a significant reduction in the original right lower lung mass, now confined to the right lower lobe ( Figure 1 ). A follow-up examination six months post-surgery (June 2019) included a full spiral enhanced CT scan of the lungs and tests for the three aforementioned serum tumor markers, all of which returned normal results ( Figure 1 ,  Table 1 ).
case_images: Microscopic Findings The biopsy specimen reveals atypical tumor cells arranged in nests, with some areas showing glandular-like infiltrative growth. The cells exhibit significant pleomorphism, with large, hyperchromatic nuclei. There is a notable presence of inflammatory cell infiltration and scattered multifocal necrosis. Immunohistochemistry Results CK +, CK5/6 -, CK7 -, P63 -, CK20 -, TTF-1 -, GATA3 -, CD30 +, S-100 -, SALL4 +, CD56 -, chromogranin A -, Syn -. Conclusion Initial assessment of the right lung tissue suggests a high likelihood of malignancy, with a strong suspicion of non-small cell carcinoma (NSCLC).Based on the immunohistochemistry results, the poorly differentiated malignant tumor in the right lower lung is highly suggestive of a germ cell tumor.
case_images: fonc-14-1361380-g002.jpg
case_images: PMC11263088_03_fonc-14-1361380-g002.jpg
case_images: f2
case_images: In the same month, a biopsy of the right lower lung mass was performed, and the pathological results indicated a germ cell tumor ( Figure 2 ).
case_images: Imaging Findings Intravenous injection of 99m-Tc-MDP was administered, and planar whole-body skeletal imaging was performed in both anterior and posterior views two hours post-injection. The results are as follows:   The whole-body bone scan is clear, with normal morphology and structure.   The radiotracer distribution in the bones is generally uniform and symmetrical, with no localized areas of abnormal radiotracer uptake or defects observed.   Both kidneys are visible in the images. Imaging Conclusion The whole-body skeletal metabolic imaging appears normal, with no evidence of bone metastasis from malignant tumors.
case_images: fonc-14-1361380-g003.jpg
case_images: PMC11263088_03_fonc-14-1361380-g003.jpg
case_images: f3
case_images: After excluding the possibility of non-testicular primary or metastatic germ cell tumors, our hospital diagnosed the patient with "primary pulmonary germ cell tumor." The preoperative evaluation, including a comprehensive ECT (electrocardiogram and cardiac test), revealed no significant abnormalities ( Figure 3 ) count showed no significant abnormalities. After excluding contraindications for chemotherapy, the patient began BEP regimen chemotherapy on September 30th of the same year (Bleomycin 30,000U on Days 1, 8, and 15; Etoposide 170mg on Days 1-5; Cisplatin 30mg on Days 1-5).
case_images: Macroscopic Examination The right lower lung lobe specimen measured 12x8x6 cm. A nodule, approximately 2 cm in diameter, was observed 3.5 cm from the resection margin and 0.3 cm beneath the pleural surface. The nodule was grayish-yellow, well-defined, and soft, with a cystic appearance on the cut surface. Microscopic Examination Hematoxylin and eosin (HE) staining revealed nests of atypical tumor cells, some resembling glandular structures infiltrating the surrounding tissue. The tumor cells varied in size, with large, hyperchromatic nuclei. There was significant infiltration of inflammatory cells surrounding the tumor, and multifocal necrosis was observed. Immunohistochemistry CK+, SALL4+, PLAP+, CK19+, CD30+, AFP+/-, Hepatocyte-OCT3/4-, HCG-, CDX2-, CEA-, CD5-, CD117-, TdT-. In situ hybridization EBER-. Conclusion: embryonal carcinoma In October 2023, the patient was admitted to our hospital due to "right testicular enlargement for more than half a month."On physical examination, the patient was 171 cm tall and weighed 69.6 kg, with a BMI of 23.80 kg/m2. The right testicle was enlarged to approximately the size of a goose egg, with a firm texture, no obvious tenderness, and no signs of local redness, heat, or pain. A multislice enhanced CT scan of the testes/epididymis at our hospital revealed an enlarged right testicle with a solid mass, suggesting a high possibility of a malignant tumor (
  Figure 5
  ). Serum levels of AFP, beta-HCG, and LDH were all within normal ranges. A multi-slice enhanced CT scan of the chest showed no signs of tumor recurrence or metastasis. On October 12 of the same year, the patient underwent a right radical orchiectomy. Intraoperatively, the testis measured 7x6.8x6 cm, and a tumor measuring 6x5x4 cm was observed upon sectioning. Postoperative pathological staging was T1bN0M0, with a clinical stage of I. Pathology indicated a diagnosis of seminoma in the right testis (
  Figure 6
  ). In 2024, the patient received antitumor treatment with carboplatin 500mg on December 12, 2023, and January 3, 2024. A follow-up examination in March 2024, six months post-surgery, included a whole-body spiral CT scan with contrast enhancement of the lungs and testes, as well as tests for the three aforementioned serum tumor markers. All results were normal (
  Figure 1
  , 
  Table 1
  ). We believe that clinical cure has been achieved.
case_images: fonc-14-1361380-g004.jpg
case_images: PMC11263088_03_fonc-14-1361380-g004.jpg
case_images: f4
case_images: Figure 4 ). Following surgery, the patient underwent four courses of postoperative BEP chemotherapy on December 29th of the same year, and on January 19th, February 12th, and March 6th of the following year, with the chemotherapy regimen remaining the same as previously administered.