Published online Mar 6, 2022. doi: 10.12998/wjcc.v10.i7.2307
Peer-review started: September 21, 2021
First decision: October 22, 2021
Revised: November 6, 2021
Accepted: January 22, 2021
Article in press: January 22, 2022
Published online: March 6, 2022
Processing time: 161 Days and 16.5 Hours
Smoldering multiple myeloma (SMM) is an asymptomatic plasma cell proliferative disorder that can progress to multiple myeloma (MM). Amyloidosis (light chain) (AL) is the most common form of systemic amyloidosis. There are few reports of SMM coexisting with AL involving the digestive tract.
A 63-year-old woman presented with lower limb edema, abdominal distension, abdominal pain, and hematochezia. Gastroscopy showed gastric retention, gastric angler mucosal coarseness, hyperemia, and mild oozing of blood. Colonoscopy showed hyperemic and edematous mucosa of the distal ascending colon and sigmoid colon with the presence of multiple round and irregular ulcers, submucosal ecchymosis, and hematoma. Gastric and colonic tissue biopsy confirmed the diagnosis of AL by positive Congo red staining. MM was confirmed by bone marrow biopsy and immunohistochemistry. The patient had no hypercalcemia, renal dysfunction, anemia, bone lesions or biomarkers of malignancy defined as plasma cells > 60% in bone marrow. Additionally, no elevated serum free light chain ratio, or presence of bone marrow lesions by magnetic resonance imaging (SLiM criteria) were detected. The patient was finally diagnosed with SMM coexisting with AL. She received chemotherapy and was discharged when the symptoms were relieved. She is doing well at nearly five years of follow up.
This case highlights that high index of suspicion is required to diagnose gastrointestinal AL. It should be suspected in elderly patients with endoscopic findings of granular-appearing mucosa, ecchymosis, and submucosal hematoma. Timely diagnosis and appropriate therapy can help to improve the prognosis of these patients.
Core Tip: We report an unusual case of smoldering multiple myeloma with gastrointestinal symptoms (abdominal distension, abdominal pain, and blood in the stool). Gastrointestinal amyloidosis (light chain) (AL) was suspected based on the endoscopic findings of granular-appearing mucosa, ecchymosis, and submucosal hematoma. The diagnosis of gastrointestinal AL was confirmed by Congo red staining of biopsied tissues. The patient was doing well at the last follow-up of 5 years after chemotherapy which is the best prognosis among the reported cases of multiple myeloma with gastrointestinal AL.