A 56-year-old woman presented with neck pain 1 month after the discovery of a thyroid nodule that developed 1 year prior. The patient was first found to have thyroid nodules by ultrasound in August 2017 (the details are unknown), and there were no symptoms of compression, hoarseness, palpitation, low-grade fever, or choking at that time. However, as the patient was only three months post-rectal cancer surgery and had a significant reaction to chemotherapy, she was extremely weak. The patient and their family chose to have regular follow-up examinations without further treatment for the thyroid nodules. Through regular follow-ups, the thyroid nodules grew larger and were accompanied by mild neck pain and enlarged surrounding lymph nodes. Therefore, the patient came to our hospital for further examination In September 2018, the patient came to the clinic after experiencing neck pain without other obvious discomfort. When palpating the thyroid gland in this patient, bilateral hard masses could be felt, measuring approximately 1.5*1.5 cm in size, with an unclear boundary, tenderness and rigidity, and the masses moved up and down with swallowing. Moreover, swollen and hard lymph nodes could be palpated on both sides of the neck, with a maximum size of approximately 2.0*1.0 cm. The rest of the physical examination showed no obvious abnormalities. Color Doppler ultrasound ( Figure 1 ) and computed tomography (CT) showed multiple nodules with increased signals in the bilateral lobes of the patient's thyroid; among them, the largest nodule on the right side was 2.0*2.0 cm and the largest nodule on the left side was 1.0*1.5 cm. The results of routine laboratory tests, including for those for thyroid function (T3, T4, TSH), liver and kidney function, and tumor markers (AFP, CEA, CA-199, CA-125, CA-153, CA-242), were normal. To further clarify the condition of the patient's lesions, we performed a puncture biopsy. Fine-needle aspiration (FNA) revealed the presence of suspicious tumor cells in the left thyroid nodule and infiltration or metastasis of malignant tumor cells in the left cervical lymph nodes. In May 2017, the patient underwent enteroscopy because bloody stools for 8 months and aggravated for the last 2 months. The result of enteroscopy suggested a rectal mass ( Figure 2A ) and the patient had previously undergone radical rectal resection for a rectal neuroendocrine neoplasm (NEN). The postoperative pathology showed a neuroendocrine tumor ( Figure 2B ), with a tumor size of 3.1cm*2.5cm, and the immunohistochemical results showed CK7[-], CK20[focal +], CKpan[+], Syn[+], CgA[-], CDX2[-], CD56[+], Ki67[5-10%], and EMA[partially+]. The postoperative pathology showed that the endocrine tumor of the rectum was a well-differentiated neuroendocrine tumor, WHO grade 2 (G2), stage IIIB. Chemotherapy with etoposide 120 mg + cisplatin 60 mg (EP regimen) was given for two cycles one month after surgery. The patient failed to continue chemotherapy due to personal reasons, and no abnormalities were found in subsequent reexaminations. Since the patient had no other distant metastatic lesions, we performed bilateral total thyroidectomy + bilateral central lymph node dissection on October 31, 2018. Postoperative pathology suggested bilateral metastatic thyroid NENs ( Figure 3 ) and the immunohistochemical results showed CK[+], TG[-], TTF1 slightly scattered[+], HBME-1[-], S-100[-], Calcitonin[-], CgA[+], Syn[+], Ki-67[+] 10-20%, CK19 [+], CK20[-], PAX 8[-], CEA[-], CDX2[-] and SATB2[-] ( Figure 4 ).
The patient underwent regular follow-up after surgery. In January 2019, liver metastases were detected in another examination, followed by multiple metastases in bone and the pelvis. Oxaliplatin 130 mg D1+ S-1 60 mg d1-7 (SOX), anlotinib, irinotecan 260 mg d1 q2w and other drugs were used successively. Ultimately, the patient died of liver metastasis in May 2022, but there was no sign of recurrence in the neck.