Atypical presentation of carcinoid tumor with unresolved right shoulder pain: a case report.

INTRODUCTION: Carcinoid tumors are variants of neuroendocrine tumors that typically arise from the gastrointestinal tract and the bronchus, but they can involve any organ. Unresolved right shoulder pain manifesting as the first clinical presentation of carcinoid tumor with unknown primary origin is a rare clinical entity. To the best of our knowledge, herein we present the first case report describing metastasis to the right shoulder joint in a patient who presented with bone pain as the first clinical manifestation of metastatic carcinoid tumor of unknown primary origin. Metastasis to the right scapula as the first presentation of an underlying carcinoid tumor in the primary bronchus has been reported previously.

CASE PRESENTATION: A 72-year-old Caucasian woman presented with pain in her right shoulder after a fall. She delayed seeking medical attention for 4 weeks for personal reasons. Her physical examination revealed no erythema or swelling of the right shoulder. However, tenderness was noted on the right subacromial bursa and the right acromioclavicular joint. Her drop arm test was positive. An X-ray of the right upper extremity showed no fracture. She did not respond to methylprednisolone injections or physical therapy. Because of the unresolved right shoulder pain with disturbance of her daily activities, magnetic resonance imaging of the right shoulder was ordered, which revealed permeative destruction of the right scapula. Because the permeative destruction of the bone could have been an osteolytic malignant feature, positron emission tomography-computed tomography was performed, which produced a scan showing osseous metastasis to the right scapula, multiple liver metastases and a 1.7 cm right-lower-lobe pulmonary nodule. Her serotonin and chromogranin A levels were significantly elevated. The patient was treated with palliative cisplatin and etoposide chemotherapy followed by locoregional treatments for metastatic carcinoid tumor. She had mild improvement in her right shoulder pain, as well as better range of motion and improved quality of life, before she died less than 2 years after her diagnosis.

CONCLUSION: Our present case report emphasizes the protean manifestations of carcinoid tumors with the importance of early diagnosis of bone metastases from these tumors, because early diagnosis plays a major role in choosing the therapeutic regimen and prognosticating the course of the disease. The treatment goals for high-grade, poorly differentiated carcinoid tumors of unknown origin are decreasing the tumor load while controlling symptoms with chemotherapy and local modality treatments.