Humeral metastasis as the only recurrence of a 5-year resected gastrointestinal stromal tumor: a case report

Abstract

Introduction Gastrointestinal stromal tumors represent the most frequently encountered primary mesenchymal tumors. Whereas the liver and the peritoneum are known to be the preferential metastasis sites, no therapeutic standard has yet been established for the management of bone metastases because of their very low incidence. We report a unique example of a single humerus metastasis of a jejunal gastrointestinal stromal tumor. Case presentation We report the case of a 72-year-old European woman whose jejunal gastrointestinal stromal tumor was resected in 2013 and treated during the following 3 years with imatinib (400 mg daily). In 2018, she developed a single humeral bone lesion that was identified as a gastrointestinal stromal tumor metastasis. After 7 months of imatinib intake, reconstructive surgery was performed. Pathologists confirmed the satisfactory histological regression and assessed the complete tumor resection. The patient is still on imatinib maintenance therapy, with no recurrence reported so far. She fully recovered the upper limb function after following an appropriate rehabilitation program. Discussion Current literature and published case reports indicate that bones are one of the rarest locations of gastrointestinal stromal tumor metastasis (about 1%), with occurrence mainly in the spine. Patients initially diagnosed with gastrointestinal stromal tumor of the small intestine and stomach are more likely to suffer from bone metastasis, compared with other gastrointestinal stromal tumor locations. The median overall survival rate is higher for patients with isolated bone metastasis compared with those having liver metastasis. Metastasis occurs on average 4 years after the primary, but it may take up to 20 years, emphasizing the need for long-term clinical and radiological monitoring. Although specific guidelines for such cases have not yet been established, we suggest that a multimodal concerted approach involving surgery or radiotherapy associated with tyrosine kinase inhibitor intake should be considered. Conclusion Bones are one of the rarest locations of gastrointestinal stromal tumor metastasis. A multidisciplinary collaboration was set up to allow conservative surgery of our patient after several months of imatinib treatment. A year and a half later, the patient is still in complete remission. This specific case supports the concept of an intermediate stage between local and oligometastatic disease that should be managed with a curative aim, as much as possible.

Clinical characteristics and prognosis of gastrointestinal stromal tumors with rare site metastasis (Review)

“…For example, when intracranial GIST metastasis occurs, it usually affects the nervous system, resulting in dizziness, headache, memory impairment, loss of sensation and inability to move a single limb, the inability to maintain body balance and abnormal gait and posture, along with a series of neurological crements (27,32,35,40,51,61,70,87,87,92,93). In cases of bone metastasis, pain manifests in the affected bone area (29,37,48,52,53,63,69,75,80,94,95), in cases of skeletal muscle involvement, a mass can be palpated in the affected area (34,49,71,72,79), and when metastasis occurs deep in the bone marrow, anemia may be present (96). Furthermore, when GIST metastasizes to the lungs, signs and symptoms that may be observed include dyspnea, blood in the sputum, coughing and shortness of breath (18,85,88,97).…”

“…However, when GIST metastasizes to the heart, although no clinical signs are evident in the early stages (24,82,83,99,100), the late stages may manifest as cardiogenic shock (43). When GIST metastasizes to the orbit, a mass may be palpable around the orbit (60) and may manifest as periorbital pain (101), and with involvement of the choroid, vision loss or diplopia may occur (44,48,51,67). Menstrual flow may increase when there is metastasis in the cervix (102), and when the testicles, penis or scrotum are involved, swelling of the testicles and scrotum, difficulty in achieving an erection and obstruction of the urinary tract are typical manifestations (21,38,64,74).…”

“…When GIST metastasizes to bone, it is primarily present in the spine (17), with CT plain scanning showing osteolytic bone destruction of the vertebral ody (29,31,37,47,52,53,69,76,78,81,84,94,95). Additionally, MRI reveals dural protrusion and compression of the spinal cord, usually with spinal stenosis, T1 and T2 high signals on enhancement scans and partial necrosis and non-uniform enhancement of the lesion (29,31,48,63,76,78,81,95). The PET-CT imaging of bone metastasis shows hypermetabolic changes at the site of a vertebral lesion (37,47,62,63,69,75,76).…”