Dear Editors,

Three cases of ‘Idiopathic Retroperitoneal Abscesses’ were reported in the issue of May’ 81.It was concluded that these cases respond well to incision and drainage and a broad spectrum antibiotic. A recent case which affirms the above conclusion is presented below.
A 25 year old male presented with pain in the left loin and fever of 20 days duration. The pain had spread to the left lumbar region since 10 days. The pain was initially throbbing and the fever high grade with rigors, but both had become less ‘characteristic’ after some treatment. He had no urinary or bowel complaints.
On examination, the patient was found to be anaemic, pulse was 132/min, and temperature was 102^oF. The concavity of the left flank was diminished on inspection and it was tender to palpation. There was tenderness and guarding in the left lumbar region anteriorly.
Investigations revealed a haemoglobin of 8 gm/dl, total leucocyte count 15,000/cumm and an erythrocyte sedimentation rate of 125 mm/lst hr. Urine examination and X-ray chest revealed no abnormality.
He was diagnosed as a case of perinephric abscess and was operated as an Emergency case. Under general anaesthesia, a left lumbar incision was given and the abscess was easily reached on deepening the incision. About I litre of pus mixed with blood was aspirated. A drain tube was retained which initially drained purulent material, but later serous fluid. The drain was removed after 7 days, but the deep sinus continued to discharge serous fluid for another 3 weeks.
Coagulase positive staphylococcus aureus was obtained from culture of the pus and the growth showed sensitivity to the antibiotics that were being administered viz. Ampicillin, Cloxacillin and Tobramycin. Ziehi-Neelsen staining did not show any acid-fast bacilli.
Post operative X-rays of the spine, in travenous pyelograms, stool examination and barium enema studies revealed no abnormality. A thorough search for a distant focus of infection was also negative. Therefore a retrospective diagnosis of Idiopathic (Isolated) Retroperitoneal Abscess was made.

Ayub A. Merchant, Mushtaq Ahmed
Civil Hospital, Karachi.