Back pain as an initial feature of advanced gastric cancer mimicking multiple myeloma: A case report and literature review

Abstract

Background: Back pain is a rare initial presentation of gastric cancer. Isolated back pain with red flags in middle-aged patients might indicate multiple myeloma. However, it is rarely present in advanced gastric adenocarcinoma; hence, data are limited to case reports only. For a timely diagnosis of the underlying malignancy, endoscopy should be considered if the initial workup for this backache is unrevealing.

Case presentation: We present a 34-year-old previously healthy gentleman with severe unremitting backache. He was ultimately diagnosed with gastric adenocarcinoma stage IV and received palliative treatment. The manuscript also reviewed relevant literature.

Conclusion: In rare cases, gastric malignancy can initially present as back pain with lytic bone lesions, mimicking multiple myeloma. Endoscopy early in the course of investigations may help reduce associated morbidities. Further, more extensive studies are required to understand better the clinical characteristics, demographics, and management of such patients.

Keywords: Back pain; Gastric cancer; Metastatic Malignancy; Multiple Myeloma.

Figure 1.

MRI spine showing multiple lytic lesions demonstrating post-contrast enhancement (widespread variable-sized bony metastatic versus myeloma lesions in the cervical, thoracic, lumbar, and sacral spine). Lesions exemplified with solid white arrows.

Figure 2.

Positron emission tomography (PET scan) of the patient revealing multiple areas of uptake. (a) The solid white arrows show vertebral osteolytic lesions at multiple levels throughout the spine. (b) The solid white arrow denotes the uptake in left-sided pleural-based lesion, and the hollow white arrow shows the uptake in segment IV of the liver. (c) The solid white arrow demonstrates the uptake in the lateral aortic lymph node, and the hollow white arrow shows hypermetabolic spleen. (d) The solid white arrow shows the uptake in the pylorus of the stomach, and the hollow white arrow demonstrates the uptake in aortocaval lymph node. (e) The hollow white arrows denote lytic lesions in the bony pelvis.

Figure 3.

Endoscopy (solid white arrow) showing gastric mass (an irregular, infiltrative lesion causing partial obstruction of pyloric channel suggestive of adenocarcinoma or lymphoma)

Figure 4.

(A) Tumor cells aggregating in small clusters and single cells (black arrows) in pools of mucin (stars). Hematoxylin and eosin (H&E) staining, 200 × . (B) Tumor cells (black arrows) infiltrating gastric submucosa. Adjacent non-neoplastic mucosal glandular lining is also noted (stars). H&E staining, 200 × . (C) Tumor cells expressing PD-L1 immunostain (black arrows). PD-L1 immunohistochemical stain, 200 × . (D) Negative Her2/neu immunostain (black arrows point at tumor cells). Her2/neu immunohistochemical stain, 200 × .