Table 2.

Summary of case reports focused on treatment of bone infections in MM patients (Jan 2000- Dec 2021).

References	Patient details	Medical history, sign, and symptoms	Infection site and causative pathogens	Treatments and clinical outcomes
Desikan, et al. (2003) [89]	72, Male	Stage IIA kappa light-chain disease, received 140 mg/m2 melphalan after induction therapy with 40 mg of dexamethasone Had a history of oxacillin-resistant Staphylococcus aureus infection, treated with intravenous vancomycin Three months later, readmitted with significant right shoulder pain and required intravenous morphine	Spondylodiscitis with prevertebral and epidural abscesses causing impingement of the cervical cord Blood culture was positive for S. aureus	Received discectomy and corpectomy of C4 and C5 vertebrae along with arthrodesis of the C3-C6 vertebrae.
Desikan, et al. (2003) [89]	56, Male	Stage IIIA IgG lambda multiple myeloma Received induction therapy and tandem transplants Recurrence of MM with severe low back pain	An MRI scan revealed spondylodiscitis of disc L4-L5 with an associated epidural abscess. Culture of the epidural abscess showed positive for Streptococcus pneumoniae with intermediate resistance to penicillin.	A partial laminectomy of L4 was performed to evacuate the epidural abscess. Received intravenous vancomycin for six weeks, and no recurrence of vertebral infection was observed. The patient suffered respiratory infections and died of progressive disease one year later.
Desikan, et al. (2003) [89]	61, Male	VAD refractory stage IIIB kappa light-chain myeloma received combination chemotherapy with dexamethasone, thalidomide, cisplatinum, adriamycin, cyclophosphamide and etoposide (DT-PACE) for stem cell procurement. Developed fever, complained of localized pain and tenderness of the lower back before admission for stem cell transplant. The back pain worsened during the post-transplant neutropenic period.	An MRI revealed spondylodiscitis of the L5-S1 disc space. A CT-guided aspirate was positive for coagulase-negative Staphylococci.	Received intravenous vancomycin for one month. The patient had no recurrence of pain. Evaluations were normal for the next three years.
Yu et al. (2010) [90]	57, Female	IgG kappa gammopathy (subsequent diagnosis of myeloma), had 3-week history of chill and low back pain. No history of trauma. The patient also had mild tenderness and knocking pain over the lumbar area. The MRI of spine demonstrated hyperintensity at the L2 body with a pre-vertebral abscess, suspected spondylitis.	Blood culture revealed Escherichia coli, and a CT-guided biopsy at the L2 vertebra confirmed infectious spondylitis.	First treated with intravenous oxacillin, then switched to cefazolin and cefuroxime. Neurological deficit was alleviated after eight weeks of antibiotic therapy. The patient was free of recurrent back pain and fever six months after discharge, and was subsequently treated with melphalan, dexamethasone and thalidomide for MM.
Mohan et al. (2016) [91]	69, Male	Relapsed refractory MM, admitted for chemotherapy and autologous stem cell transplant (ASCT). He was diagnosed with MM and had been heavily treated in the past including three prior ASCTs. He was admitted for velcade, dexamethasone, thalidomide, adriamycin, cytoxan, and etoposide administration days 1 to 4, with one dose of melphalan and ASCT on day 6. He developed new onset atrial fibrillation with acute renal failure, and the neutropenic phase was further complicated with sepsis caused by vancomycin- and daptomycin-resistant Enterococcus faecium bacteremia. The infection was successfully treated with quinapristin-dalfopristin.	Lasiodiplodia On day 6 post ASCT, the patient reported new swelling and erythema of the third right toe. Physical examination showed hemorrhagic bullae around the nail with reddish discoloration of the entire third right toe and minimal oedema.	Successfully treated with amputation and antifungal medications (oral voriconazole alone after 14 days of liposomal amphotericin B).
Park et al. (2016) [92]	74, Female, Korean	Fever and diffuse abdominal pain and septic shock Multiple myeloma, had 2 cycles of chemotherapy with thalidomide-cyclophosphamide-dexamethasone for relapsed MM after previous chemotherapy with bortezomib-melphalan-prednisolone and lenalidomide-dexamethasone	Escherichia coli in blood culture Chest computed tomography (CT) showed incidental intraosseous gas in her sternum and T6 vertebra, suggesting emphysematous osteomyelitis	Meropenem and supportive treatment The patient recovered and was discharged 20 days later.
Webber et al. (2017) [93]	25, Male	Femoral pyomyositis, hypercalcemia, mild anaemia, and elevated inflammatory markers. Diagnosed with IgG kappa multiple myeloma.	Streptococcus pneumoniae Femoral pyomyositis	Received zoledronic acid therapy for hypercalcemia. Completed a 4-week course of IV ceftriaxone.Received bortezomib-lenalidomide-dexamethasone (VRd) therapy and autologous bone marrow transplant. One year later, the swelling and the leg/thigh pain had resolved.
Cohen et al. (2019) [94]	56, Male	Undiagnosed multiple myeloma with severe sepsis associated with pneumonia, meningitis, polyarthritis, and osteomyelitis	Haemophilus quentini	Not determined.
Sassine, et al. (2021) [95]	77, Male	Had multiple myeloma treated with lenalidomide, developed a slowly progressive right upper thigh pain with no antecedent trauma or known history of osteolytic lesions. PET-CT showed a right proximal femoral diaphysis lesion with cortical destruction and intensely avid FDG uptake.	Tissue cultures positive for Cryptococcus neoformans. Bone histology was consistent with cryptococcosis. Serum positive for cryptococcal antigen.	Received intravenous liposomal amphotericin B (5 mg/kg daily) for one week and was discharged on a high dose (800 mg/d) of oral fluconazole. Had nailing of the femur to prevent fracture, following a switch to oral voriconazole (300 mg twice daily) for three months.
Roque et al. (2021) [96]	57, Male	Had lumbar pain, paraplegia, and fever. Diagnosed with spondylodiscitis. MRI identified a mass extending from D9 to the vertebral canal with numerous adjacent osteolytic lesions. A plasmacytoma was confirmed by C9′s biopsy.	B. melitensis	A short course of radiation therapy and high-dose corticosteroids were used to treat the patient.