Community-Acquired Pneumonia And Solitary Bone Plasmacytoma In A Diabetic Patient
Introduction
Methicillin-resistant Staphylococcus aureus (MRSA) is being recognized increasingly as a cause of community-acquired infection. The organism usually causes skin and soft tissue infection. CA-MRSA strains were first reported in the 1980s, and were responsible for an outbreak of infection in intravenous drug users in North America. Later outbreaks were documented in separate community populations such as Australian aborigines, Native Americans, soldiers, male homosexuals, prisoners, and athletes. Although the reasons for MRSA emergence in these groups is not clear, possible commonalities include crowding, poor hygiene, socioeconomic factors, and extensive previous antibiotic use. The prevalence of CA-MRSA has increased in Saudi Arabia in the past 10 years, and CA-MRSA infections in healthy individuals without established risk factors have now been documented in the community in Saudi Arabia. The first CA-MRSA infections were reported from King Fahd Hospital of the university in the Eastern Province and within a short period of time, these strains spread widely in the community. The prevalence of CA-MRSA infections in KSA increased from 9. 9 per 10 000 admissions in 2001 to 67 per 10 000 admissions in 2008. The emergence of pandemic CA-MRSA clones not only limits therapeutic options but also presents significant challenges for infection control.
However, it may occasionally cause invasive and severe infections like necrotizing pneumonia, necrotizing fasciitis, pyomyositis, osteomyelitis, and sepsis. Spondylodiscitis due to staphylococcus aureus represent 2%-16% of MRSA cases. Excessive fighting with infection can leads to plasma cell neoplasm.
Case presentation
In March 2018, a 48 years old Saudi male known case of Diabetis Mallitus for 18 years presented to emergency department complaining of left sided back pain for 5 days started after he accidently hit a table on the site of the complaint. He denied any respiratory complaints. The temperature was 36. 5 C, Heart rate 70, blood pressure 135/87, and oxygen saturation on room air was 91%, and respiratory rate 26. His chest examination revealed decreased air entry with crepitations bilaterally. upon inspecting the back, he was noticed to have a crescent shaped scar on the site of trauma with tenderness on palpation, also a rounded shaped scar on the mid-upper back due to previous drained abcess was noticed, an amputated little toe of right foot was noticed.
Initial laboratory studies, including complete blood count, renal function test, coagulation profile, and ESR were remarkable for a white blood cell (WBC) count of 14. 69 cell/ul (normal, 4500-11, 000 cell/ul ) and ESR count of 100 mmhr (normal, 0-20 mmhr), initial chest radiograph showed diffuse bilateral patchy air space opacity with cardiomegaly and bronchogram and lower zonal atelectatic band. Sputum, blood cultures, HIV, and H1N1 were obtained. By hospital day 3, blood cultures were reported to be growing MRSA. Both H1N1 and HIV tests were reported as negative. Echocardiogram was requested to rule out infective endocarditis and was negative. D-test reported sensitive for macrolides and clindomycin. he was started on IV clindamycin 900 mg three times daily. chest radiograph repeated only one day after starting the antibiotic which revealed marked interval resolution of the bilateral large butterfly consolidation but lower zonal atelectatic band still seen. Repeated blood cultures after one week were Negative, but Repeated ESR indicated increasing from 100 mmhr at day of admission to 120mmhr. still the patient was complained of progressive back pain developed to inability to walk. neurosurgeon was consulted. on examination, decreased muscle power, positive Babinski sign on left leg more than right leg have been noticed. MRI of the spine was done which showed multi-level discopathy spicifically at T9-10 with exiting nerve root conflict.
High resolution CT-scan of the chest concluded Perivertebral multiloculated fluid collection at the level of T 9-10 with adjacent vertebral bodies destruction with abscess formation. Posterior spine fixation has been done by neurosurgeons at the site of spinal destruction. biopsy of T9 vertebral body diagnosed histopathologically plasma cell neoplasm.
Discussion
MRSA commonly affect the skin, and less commonly affect the lung, and rarely affect bones and spine. Community acquired MRSA has higher prevalence in patients with uncontrolled diabetis mallitus, ischemic heart disease, and alcoholism. MRSA is a notorious organism causing Infections mainly in Health Care Institutions. Outbreaks of such infection in hospitals are also accelerated with marked increase in morbidity and mortality. Center for disease control and prevention (CDC) reported that “more than 90, 000 life-threatening illness and nearly 19, 000 deaths associated with MRSA occur yearly in the United States”. During the 2006-2007 in the United State reported mortality rate 51% due to MRSA associated pneumonia. KSA covers over 2 million Km2 area and estimated population over 27 million and considered potentially hot spot for the collection of MRSA because up to 6 million of their populations are expatriates from many countries. However, In Saudi Arabia, very few studies have been conducted so far to investigate the incidence or prevalence of MRSA(2). The majority of MRSA infections are cutaneous, involving cellulitis, an abscess, or both. Pain and pus production at the site of infection are characteristic of S aureus infection. Cutaneous MRSA lesions will frequently occur at the site of an abrasion or cut, even if the injury is mild. The first step in confirming MRSA is to isolate S. aureus from a culture of blood, tissue, or pus. If S. aureusis not found in a culture, it is unlikely that the individual has MRSA. Cultures may also be obtained when a cluster of infections is reported, when local infection is severe, or when there is systemic infection.
MRSA associated community acquired pneumonia should be suspected when patient admitted as a case of pneumonia associated with recent history of furuncles, hemoptysis, or sputum culture resulted positive for gram positive cocci. Our case has history of multiple abscesses and gram positive cocci in sputum culture, C-xray showed diffused patchy opacities which can indicate as a radiological finding of severe pneumonia. the incidence of non specific spondylodiscitis is about 1:250, 000. 36% of s. aureus cause spondylodiscitis, which should be brought in mind for diffuse back pain cases. Spondylodiscitis means infection of interverterbral disc associated with secondary infection of vertebral bodies. MRI is a diagnostic modalities of detecting spondylodiscitis. CT scan is inferior to MRI which respect to the specificity and sensitivity in the diagnosis of spondylitis. CT scan can provide more detailed image regarding bone destruction and providing good image for paravertebral abscess.
MRI and CT scan have been useful in our case. MRI without contrast indicated multi-level discopathy spicifically at T9-10 with exiting nerve root conflict. CT-scan of the chest concluded Perivertebral multiloculated fluid collection at the level of T 9-10 with adjacent vertebral bodies destruction. Bone biopsy and aspiration of parvertebral abcess in like this case is essential to avoid any catastrophic complications, It is important to exclude TB or malignancy. In our case: the biopsy indicated plasma cell neoplasm. Plasma cells develop from B lymphocytes (B cells), a type of white blood cell that is made in the bone marrow. Normally, when bacteria or viruses enter the body, some of the B cells will change into plasma cells. The plasma cells make antibodies to fight bacteria and viruses, to stop infection and disease.
Plasma Cell Neoplasms are a family of disorders characterized by clonal proliferation of a plasma cell. These include: Multiple Myeloma (MM) and its precursor states MGUS and SMM, solitary osseous or non-osseous plasmacytoma, POEMS syndrome, heavy chain disease, and systemic AL amyloidosis.
Monoclonal gammopathy of undetermined significance (MGUS)which less than 10% of the bone marrow is made up of abnormal plasma cells and there is no cancer and it is asymptomatic. multible myeloma criterized as the following :
- Clonal bone marrow plasma cells OR
- Biopsy proven bony or extramedullary plasmacytoma AND any one or more of the following myeloma-defining events: End organ damage (CRAB) Hypercalcemia, Renal insufficiency, Anemia, Bone lesions.
Plasmacytoma is Well defined, monoclonal proliferation of plasma cells that occurs inside (solitary bone plasmacytoma) or outside (extramedullary plasmacytoma) the bone. Generally speaking, a common yet nonspecific clinical symptom of solitary bone plasmacytoma (SBP) is pain. Motor and sensory deficits can also occur, secondary to nerve impingement from compression fractures.
Complications of SBP include pathological fractures due to lytic bone disease. According to our case : history of persistent back pain which developed gradually to motor and sensory deficit, histopathological finding which strongly suggest plasma neoplasm confirmed by showing CD138, CD38, CD 79, Kappa, and lambda, and radiological finding of veretebral body destruction and pathological fracture with nerve root compression suggest solitary bone plasmacytoma. the definitive treatment for SBP is radiotherapy. Plasmacytoma of the bone often becomes multiple myeloma when plasma cell tumor continue to grow and reaching >30%.
The treatment of MRSA is based upon the type of infection, the location, and the severity. For skin abscesses, medical care using incision and drainage is the treatment of choice. Vancomycin continues to be the drug of choice for treating most MRSA infections caused by multi-drug resistant strains. Clindamycin, co-trimoxazole, fluoroquinolones or minocycline may be useful when patients do not have life-threatening infections caused by strains susceptible to these agents. In a single institution with a low rate of clindamycin resistance, there were no significant differences between vancomycin and clindamycin for the treatment of these hospitalized patients with MRSA infections, on the basis of clinical outcomes data. Because of high rate of complications due to vancomycin injection in comparing to clindamycin injection, and because D-test indicated no resistant for clindamycin, so clindamycin was preferred in this case.
