Patient and tumor characteristics
A total of seventeen patients were analyzed retrospectively. None of the patients had a previous history of malignant disease. The median age of the study population was 24 years (range 6–50 years). Most cases were female (11/17, 64.7%). Among the seventeen cases of YSTs, 8 cases were ovarian YSTs, 3 cases were mediastinum YSTs, 2 cases were testis YSTs. 94.1% patients had a markedly raised AFP. Clinicopathological features of patients were showed in Table 1. Some typical cases are described below. Clinicopathological features, treatment and follow up of the patients are discussed and summarized in Table 2.
Table 1
Clinicopathological features of patients.
| No. | % |
Age at initial treatment | | |
Median 24 years | | |
Range 6–50 years | | |
Gender | | |
Male | 6 | 35.3% |
Female | 11 | 64.7% |
Primary site | | |
Ovary | 8 | 47.1% |
Mediastinum | 3 | 17.6% |
Testis | 2 | 11.8% |
Other sites | 4 | 23.5% |
Pathology | | |
Pure YST | 12 | 70.6% |
Mixed tumor | 5 | 29.4% |
AFP | | |
Raised | 16 | 94.1% |
Normal | 1 | 5.9% |
YST, Yolk sac tumor; AFP, Alpha fetoprotein. |
Table 2
Clinicopathological features, treatment and follow up of patients.
Case identity | Gender | Age at diagnosis | Symptoms and signs | Tumor site | Imaging findings | Pathological type | Immunohistochemistry | Treatment | Follow up |
1 | F | 6 | Abdominal distension | Ovary | A huge mixed density mass of pelvis | YST plus teratoma | AFP+, SALL4+ | Surgery plus PEB chemotherapy | Alive, DFS 63 m |
2 | F | 23 | Abdominal distension, pelvic mass and ascites | Ovary | Pelvic mass, metastatic nodules, peritoneal effusion | YST | AFP+, SALL4+, ki-67 + 5% | Surgery plus PEB chemotherapy | Alive, DFS 75 m |
3 | F | 31 | Negative | Ovary | Ovarian mass | YST | AFP+, SALL4+, ki-67 + 35% | Surgery plus PEB chemotherapy | Alive, DFS 58 m |
4 | F | 50 | Pelvic mass | Ovary | Pelvic cystic solid mass | YST | AFP+, SALL4+ | Surgery plus PEB chemotherapy | Alive, DFS 5 m |
5 | F | 31 | Left lumbago | Kidney | Cystic mass of left kidney | Mixed germ cell tumor (mainly YST) | AFP+, SALL4+, ki-67 + 40% | Surgery plus TP chemotherapy | Alive, in treatment |
6 | M | 23 | Cough | Mediastinum | Mediastinal mass, pleura nodules | YST | AFP+, SALL4+, ki-67 + 70% | Surgery plus PEB chemotherapy | Alive, DFS 21 m |
7 | M | 24 | Dry cough, fever | Mediastinum | Mediastinal mass, lymph nodes, pleural effusion | YST | AFP+, SALL4+, ki-67 + 70% | Palliative care | Died 2 months after diagnosis |
8 | M | 28 | Back pain, intermittent fever, night sweats | Testicle | Testis mass | YST | AFP+, SALL4+, ki-67 + 50% | Surgery, chemotherapy, immunotherapy | Relapse 6 months after diagnosis |
YST, Yolk sac tumor; AFP, Alpha fetoprotein; SALL4, spalt like transcription factor 4; PEB, cisplatin, etoposide, and bleomycin chemotherapy; DFS, disease free survival. |
Case 1
A 6-year-old girl was admitted to the hospital mainly after "left ovarian tumor ablation". The patient had unintentionally found abdominal distension more than 3 months ago, and then went to the local hospital for "left ovarian tumor ablation". Postoperative pathology showed immature teratoma of left ovary. No further treatment was performed, and a review of ultrasound after 3 months showed that there was a solid placeholder in the pelvic cavity. Physical examination can touch a solid mass of about 50 * 30 mm in size in the muscle layer between the lower abdominal wall, and a solid mass of about 15 cm in diameter in the right attachment area, which has an irregular shape, poor movement, and no tenderness. Imaging examination of CT suggests a huge mixed density mass of pelvis. Then the patient underwent left appendix plus appendectomy plus pelvic metastases resection, histological examination showed mixed germ cell tumor, yolk tumor and teratoma components can be seen. After surgery, the patient subsequently underwent six cycles of PEB combination chemotherapy. The patient was diagnosed and treated in 2014 and was alive without recurrence to now.
Case 2
A 23-year-old woman with no significant past medical history was admitted to the hospital presented with a 7-days history of abdominal distension and found pelvic mass and ascites for 2 days. Physical examination can touch a solid mass of about 18 * 12 cm in size in the right accessory area. Imaging examination of CT suggests a huge mass in the right lower abdominal pelvic cavity, multiple metastatic nodules in ovarian and peritoneal, and massive peritoneal effusion (Fig. 1A). Simultaneously the patient had a markedly raised AFP (> 1210 ng/mL). In order to confirm the diagnosis, the patient received laparoscopy plus pelvic tumor biopsy, after placement of the microscope, the pelvic peritoneal cavity had a light red bloody ascites of about 3000 ml. There were multiple white nodules on the peritoneal surface of the pelvic peritoneum, and a tumor of about 18*15*12 cm was seen on the right appendix. Biopsy pathology confirmed ovarian YST. The patient's clinical stage is too late to undergo surgery, two cycles of PEB combination preoperative chemotherapy was conducted. After 2 cycles, the original right lower abdominal pelvic mass was significantly smaller than before, the omentum was not thickened, and the peritoneal fluid disappeared. AFP declined to 38.03 ng/mL. Then, the patient underwent right ovariectomy and 4 cycles of adjuvant PEB combination chemotherapy. The patient was diagnosed and treated in 2013 and was alive without recurrence to now (Fig. 1B).
Case 3
A 31-year-old woman was admitted to the hospital presented with a 2-days history of ovarian mass. The patient is special, because she was already 32 weeks pregnant. During the previous pregnancy physical examination, no abnormalities were found. Until 2 days ago, an ultrasound examination during pregnancy revealed an ovarian mass. Ultrasound examination shows that the ovarian mass is more likely to be malignant. Simultaneously the patient had a markedly raised AFP (> 1210 ng/mL). The patient refused surgery because she was only 32 weeks pregnant. After 4 weeks, the patient underwent concurrent cesarean section and left appendectomy. The child is healthy. Postoperative pathology: ovarian YST, IHC: inhibin (-), CD99(+), CD117(+), PLAP+/-, AFP (+), CKmix (+), Ki-67 > 35%, SALL4 +, CK7(-). After surgery, the patient subsequently underwent six cycles of PEB combination chemotherapy. During treatment, AFP decreased from > 1210 ng/mL to 26.44 g/mL. After the treatment, the patient was regularly reviewed in our hospital, and since 2015, she was in stable condition with no signs of recurrence.
Case 4
A 50-year-old woman was admitted to the hospital presented with a 10-days history of pelvic mass. This is a post-menopausal woman. The patient underwent an ultrasound examination at the local hospital 7 years ago, which revealed a pelvic mass. There was no discomfort symptom such as abdominal pain and bloating. She had not undergone treatment and had not been reviewed regularly. Until 10 days ago, the patient had lower abdominal pain without obvious incentives. Ultrasound examination showed that a 144 × 95 mm cystic solid mass was seen on the right side of the uterus in the pelvis, with clear borders and uneven internal echo, several cystic echoes were seen. Then the patient underwent abdominal exploratory surgery, during the operation, a large cystic solid mass was found on the left side of the pelvic cavity, which originated from the left ovary. Left appendectomy was performed. Postoperative pathology showed left ovarian YST. After surgery, the patient subsequently underwent 4 cycles of PEB combination chemotherapy and 2 cycles of VP-16 chemotherapy. During treatment, AFP decreased from 4496 ng/mL to 3.42 ng/mL. In November 2019, the patient completed the last cycle of chemotherapy and is currently in good condition.
Case 5
A 31-year-old woman was admitted to the hospital presented with a 5-days history of left lumbago. The patient's previous medical history was reviewed, 8 years ago, she went to the hospital for a gynecological disease. Ultrasound examination revealed a left kidney cyst but was not treated. Until 5 days ago, the patient had left lumbago. Imaging examination of CT suggests a huge cystic mass of left kidney of about 67 * 64 mm in size, a retroperitoneal cystic mass, 69*57 mm in size. Then the patient underwent left nephrectomy plus left retroperitoneal mass resection plus abdominal adhesion release surgery. Postoperative pathology showed left kidney mixed germ cell tumor (mainly composed of YST). After surgery, the patient subsequently underwent 5 cycles of docetaxel + nedaplatin combination chemotherapy. Unlike the previous cases, the patient's AFP level has been within the normal range. Currently, the patient was preparing for the sixth cycle of chemotherapy.
Case 6
A 23-year-old man was admitted to the hospital presented with a 1-month history of cough. More than 1 month ago, the patient developed cough without accompanying symptoms such as asthma, chest tightness, chest pain, hoarseness, cough, and dyspnea. Anti-inflammatory and cold medicine treatments were not effective, and the symptoms continued. CT examination at the local hospital showed that irregular masses were seen in the anterior mediastinum. Imaging examination of CT suggests an irregular anterior mediastinal mass, 101*65 mm in size, and slightly enlarged lymph nodes in the mediastinum by 10 mm in diameter (Fig. 2A). AFP level is 33.33 ng/mL. Then the patient underwent resection of right anterior mediastinal mass + partial resection of right middle and upper lobe surgery. Postoperative pathology showed: (right anterior mediastinum) morphology and immunohistochemistry were consistent with YST. An additional mediastinal lymph node is sent 0/1. IHC: CK7-, TTF-1-, NapsinA-, CD30-, CD117 +, PLAP +, ki-67 + 70%, AFP +, SALL4 +, CK8/18 +, VIm-, CK +. Patient did not receive chemotherapy after surgery, 3 months later, CT showed multiple nodules in bilateral pleura, considering the possibility of metastasis, AFP level increased from 33.33 to 37.58 ng/mL (Fig. 2B). The patient underwent 4 cycles of PEB combination chemotherapy, CT evaluation of clinical efficacy as CR after chemotherapy. AFP decreased from 37.58 ng/mL to 1.51 ng/mL. The treatment was completed in May 2018 and the condition is stable now (Fig. 2C).
Case 7
A 24-year-old man was admitted to the hospital presented with half a month history of dry cough. Half a month ago, the patient developed a dry cough without chest discomfort, chest pain, and other discomforts. He developed low fever at night, which can reach 38 ° C at high temperatures. Later, the patient's symptoms gradually worsened, and chest discomfort, asthma and other discomforts appeared. Chest CT revealed a huge mass in the anterior mediastinum of the chest, considering lung cancer. "Paclitaxel + carboplatin" was given for 1 cycle of chemotherapy. After coming to our hospital, a biopsy of the mediastinal mass was performed, and the pathology proved to be YST. CT showed an anterior mediastinal mass of 112*72 mm, multiple lymph nodes in the left clavicle and mediastinum, pleural effusion, multiple nodules in the lungs and liver, and metastases were possible, right brain metastasis with peripheral edema. Patients are generally in poor condition and cannot tolerate chemotherapy. Mediastinal masses and metastatic lesions progress rapidly in a month, followed by cerebral hemorrhage.
Case 8
A 28-year-old man was admitted to the hospital presented with half a month history of right testicle tumor. The patient had an enlarged right testicle 2 months ago, and later had back pain, intermittent fever, up to 39 ° C, night sweats, and MRI showed that the right testicle increased in volume with abnormal signal occupying, 29*18*34 mm in size. CT suggests multiple metastases in both lungs. Then the patient underwent right testis and epididymis resection surgery, postoperative pathology showed: right testis YST. After surgery, the patient subsequently underwent 4 cycles of PEB combination chemotherapy. After chemotherapy, CT shows shrinkage of bilateral lung metastases, but the patient did not undergo maintenance chemotherapy. After half a year, both lung nodules increased compared to the previous, and multiple brain metastases appeared at the same time. Later, the patient received Keytruda (Pembrolizumab) immunotherapy, liposomal doxorubicin, paclitaxel chemotherapy, cranial radiotherapy, and local interventional therapy. Despite multiple treatments were given, the treatment is not effective.