A 67-year-old woman presented with a five-year history of intermittent chronic pain in her right upper arm. During the last month prior to admission to the Department of Nuclear Medicine of our hospital in December 2022, the pain had notably intensified.
Five years earlier, the patient experienced acute pain in her right upper limb following a fall, although no skin injuries were evident. At that time, she did not undergo any imaging investigations and sought treatment from a traditional healer who prescribed her some herbal medicine. However, despite this intervention, the pain persisted for a continuous period of five months and progressively intensified. Her concern escalated when she experienced a loss of mobility in her right upper limb and finally sought medical help. Subsequent X-ray imaging revealed evident erosion of the proximal humeral cortex and bone marrow, indicative of lytic bone metastasis. A subsequent bone biopsy confirmed the diagnosis of bone metastasis from follicular thyroid carcinoma (Fig. 1A). Orthopedic specialists recommended potential surgical interventions such as tumor excision or amputation for the metastatic lesion in her right humerus. However, the patient declined any surgical intervention. Over the subsequent five years, she pursued alternative methods of care, including massage, stretching exercises, and herbal medicine. In the month preceding her admission, she reported increased nocturnal pain in her upper limb, which subsided to some extent during daytime movement.
The patient's medical history from five years ago was characterized by extensive diagnostic endeavors aimed at confirming the presence of humeral metastasis. These efforts encompassed a series of procedures, including computed tomography (CT) scan, ultrasound, magnetic resonance imaging (MRI), and needle biopsy of her right upper arm, all of which corroborated the thyroid as the primary site of cancer. Following these diagnostics, the patient underwent partial thyroidectomy and modified lymph node dissection performed by a surgical team. Postoperative pathological examination confirmed classical follicular thyroid carcinoma, with evidence of capsular and lymphovascular infiltrations (Fig. 1B). Thyroid ablation was administered twice, two months and six months post-surgery, respectively, cumulatively reaching a total dose of 131I at 200 mCi. To maintain a target thyroid stimulating hormone (TSH) level below 0.1 µIU/mL, the patient received levothyroxine treatment. Despite the utilization of herbal medicines and L-T4 administered twice daily for over a year to treat the metastatic lesion in her right humerus, the patient experienced no significant pain relief. Moreover, the swelling of her right upper arm progressively worsened. In terms of personal and family history, the patient had no reported instances of food or drug allergies, or genetic diseases.
During the physical examination, a prominent observation was the presence of severe swelling in the middle and proximal regions of the upper arm (Fig. 1C, D, E). Sensory modalities were generally intact, although there was a minor impairment in light touch sensation in her right upper arm. Notably, active movement in her right shoulder was obviously restricted, encompassing limitations in flexion-extension, adduction-abduction, and internal-external rotation (Supplementary videos 1–3). In contrast, the patient exhibited relatively unimpaired motion in her forearm, including flexion-extension of the elbow, pronation-supination of the proximal radioulnar joint, flexion-extension, and radioulnar deviation of the wrist, as well as flexion-extension, adduction-abduction, opposition, and retropulsion of the fingers. Thus, she could still complete her daily living activities independently.
Given the complexity of the case, a series of imaging examinations were performed to comprehensively evaluate the patient's condition. A CT scan of the right shoulder highlighted metastases of follicular thyroid carcinoma in the right humerus, both lungs, and axillary lymph nodes (Fig. 2A, B). Furthermore, a whole-body bone scan showed lytic bone destruction in the lower humerus and the complete absence of bone in the upper middle humerus, indicative of metastasis in the right shoulder and right humerus (Fig. 2D). The thyroid emission computed tomography (ECT) scan revealed residual functional tissue with poly 99mTcO4 in the thyroid site, though distinct poly 99mTcO4-functional tissue metastases were not observed in the neck region (Fig. 2C). Ultimately, the final diagnosis for the patient was identified as follicular thyroid carcinoma with metastasis to the right humerus as well as both lungs.
In terms of treatment, on the one hand, postoperative pathological examination confirmed differentiated thyroid cancer with metastasis to the proximal right humerus and both lungs. On the other hand, the thyroglobulin (Tg) levels are markedly elevated, accompanied by pronounced swelling in the proximal right humerus, necessitating consideration for Radioactive Iodine (131I) treatment (Fig. 2E). Upon consultation with the surgical team, evident bone destruction was noted in the proximal right humerus, raising the possibility of amputation. However, detailed discussions with the patient revealed that since the functionality of her right hand remained intact, she harbored concerns on surgical intervention finally declined it. Consequently, the administration of L-T4 was temporarily halted, and the efficacy of 131I treatment was slated for assessment. Subsequent therapeutic options will be contemplated based on the evolving clinical situation. Given the notable local swelling and tenderness and the presence of large fluid-filled regions evident on the CT scan and MRI, the patient underwent 131I treatment without experiencing specific discomfort. A follow-up plan included a recommendation for the patient to visit the orthopedic department approximately 3 to 4 weeks post-discharge for local fluid aspiration.
As of June 2023, magnetic resonance imaging (MRI) examinations of the patient's right shoulder and right upper arm indicated no significant progression in comparison to earlier results (Fig. 3). Furthermore, we performed a physical examination on the patient (Supplementary videos 4–5). The patient's general condition remained stable, and the mobility of her right forearm exhibited no substantial alterations relative to previous assessments. However, the patient maintained her stance against any surgical intervention for her right upper arm.