Case of Myeloma with Psoas Abscess mimicking TB Spine reported

Dr R K Sharma, Dr Dharmendra S Bhadauria and Dr Anupama Kaul from the Department of Nephrology, Sanjay Gandhi PGIMS, Lucknow and colleagues have reported a Case of PUO, Psoas Abscess, and Renal Failure. The case has appeared in the Journal of Association of Physicians of India.

Pyrexia of unknown origin (PUO) is a common phenomenon. Abscesses are well known to present as PUO. The authors have presented a case of PUO due to psoas abscess and renal failure, with a rare manifestation of a common entity.

The study demonstrated the case of a 37 yr old male farmer presented with a history of low-grade fever and low back pain for one month. With these complaints, he was evaluated by his physician. Haemogram and ESR were normal. Chest X-ray was unremarkable. CT scan of the abdomen (Figure 1) showed the collapse of a third lumbar vertebra with large paravertebral and psoas abscess with bilateral sacroiliitis.

Further, he was considered to have Koch's spine and was started on rifampicin, isoniazid, pyrazinamide, and ethambutol. After 3 weeks, the patient reported back with recurrent vomiting and was re-evaluated. He was found to have renal dysfunction (serum creatinine 6.2 mg/dl). He was referred to our institute for the management of renal failure.

After the clinical evaluation, the authors found that there was a history of weight loss of 6 kg in the past month. The patients also had severe anorexia and malaise. There was no significant past history. Clinical examination was unremarkable. The evaluation showed hemoglobin of 9.1 gm/dl, with leukocyte count being 7800 cells/cumm.

Other results were as follows: blood urea nitrogen-180mg/dl, creatinine 7.5mg/dl, ESR 36mm/hour, protein 8.0mg/dl, albumin 3.6 mg/dl, calcium 10.0mg/dl. His urine analysis had trace albuminuria and bland sediments. 24-hour urine protein was 1.7gm. Ultrasound of the abdomen was done, which revealed bilateral normal-sized kidneys, and heterogeneous collection over psoas muscle. CT reconfirmed the findings of the first scan done elsewhere. Ultrasound-guided aspiration of the psoas collection was done.

The cytology smear showed atypical plasma cells (Figure 2). Bone marrow biopsy was reported to be multiple myeloma. Free light chain assay proved it to be a kappa light chain myeloma. Immunofixation electrophoresis showed it to be of IgG origin. He was having cast nephropathy on renal biopsy. He was treated with 5 sessions of plasmapheresis and hemodialysis. He was given bortezomib and dexamethasone based chemotherapy. His urine output improved to 1.2-1.5 liter per day from 100-300 ml per day. He remained dialysis-dependent. He had refractory disease and died within eleven months of diagnosis.

Explaining the takeaway points of the case study Dr R K Sharma wrote that "psoas collections should always undergo cytopathological examination which is a simple procedure. This would be crucial for early diagnosis. Myeloma needs chemotherapy while spinal TB would need antitubercular treatment." "delaying aspiration the diagnosis was delayed by 4 weeks" he adds.