In March 2010, a 65-year-old woman was transferred from the National Police Hospital (NPH) to our facility, Shinchon Severance Hospital (Seoul, Korea) via the emergency room (ER), presenting with a decreased level of consciousness. According to her medical history, she had hypertension, diabetes mellitus for 10 years, recurrent cystitis, and degenerative arthritis. She had been taking dexamethasone (5 mg, once a day) for the degenerative arthritis for approximately five years up to the time of admission. Three weeks before the admission, she had been hospitalized at NPH due to drowsy mentality for 3 or 4 hours. On the day of admission at NPH, she presented with a fever (38.8
) and dyspnea. The patient was given antibiotics (ceftriaxone and azithromycin) for 14 days, on suspicion of community-acquired pneumonia. Thereafter, her presenting symptoms were improved, but she complained of consistent pain in the left lower quadrant of the abdomen. Abdomen-pelvis computed tomography (CT) scan was performed, which showed the mass-like lesion in the left renal area suspecting abscess. While being treated with ciprofloxacin, she developed a decreased level of consciousness.
Upon physical examination on the day of the admission to our hospital, her initial vital signs were as follows: blood pressure 134/71 mm Hg, pulse rate 95 bits per minute, body temperature 36.4
, and respiration rate 18 breaths per minute. Her level of consciousness was drowsy. Her breathing sound was clear, and her heart sound was normal without any murmurs. There was no specific finding upon abdominal examination without peripheral edema. Laboratory studies had the following results (reference values): low sodium (Na) levels of 112 mmol/L (135.0-145.0), potassium (K) 3.4 mmol/L (3.5-5.5), chloride (Cl) 77.0 mmol/L (98-110), total CO2
21.0 mmol/L (24-30), low serum osmolality 240.0 mOsm (289.0-308.0), and normal urine osmolality 315.0 (50.0-1200). The thyroid function test was normal. Morning serum cortisol levels decreased to 7.1 (). Initial urinalysis results showed 3-5 white blood cells/high-power field and yeast-like organisms. In the radiological examination, there was no acute ischemic lesion in the brain magnetic re sonance imaging and angiography with neck angiography (3D), and no specific finding on the chest X-ray. Sodium replacement therapy for hypotonic euvolemic hyponatremia had been started from the day of admission. At that stage, secondary adrenal insufficiency due to exogenous steroid was suspected. A low dose adrenocorticotropic hormone (1 µg cosynthropin) stimulation test was conducted to diagnose the secondary adrenal insufficiency. The stimulation test showed that there was adrenal insufficiency; basal level of cortisol 8.56 µg/dL, peak level during the hour-long test 13.94 µg/dL (). Steroid hormone (hydrocortisone sodium succinate; solucortef) was replaced.
Results of laboratory analysis performed on the day of hospitalization.
Results of low dose adrenocorticotropic hormone stimulation Test on the third day of hospitalization.
On the third day after admission, her general condition including clear consciousness was improved, with a normal level of serum sodium (136 mmol/L), and her steroid hormone dosage had been gradually tapered down and was maintained at 7.5 mg (5 mg, 2.5 mg two times a day) of prednisolone acetate. However, the patient complained of myalgia, which was accompanied with leukocytosis (white blood cell count 13,650 µg/L [neutrophil 84.9 %]). Radiological reading of the abdomen-pelvic CT conducted on the second day after admission showed that there was an ill-defined inflammatory lesion with multifocal abscess pockets in the left perirenal space, which was suspected of actinomycosis of the descending colon, extended to the left kidney (). Compared to the abdomen-pelvic CT finding performed outside, the lesion seemed to have decreased slightly in size. Urinalysis was repeated and showed many white blood cells per high-power field and yeast-like organisms, which was confirmed as yeast in the urine culture. Considering the laboratory and radiologic findings, intravenous antibiotic treatment was started (ubacillin 1,500 mg a day) for suspected actinomycosis. No specific lesion was found at the colonoscopy performed to confirm the diagnosis of actinomycosis.
Figure 1 Abdomen-pelvic computed tomography (CT) scan. An abdomen-pelvic CT image obtained on the second day after admission (A) shows an ill-defined inflammatory lesion in the left kidney with multifocal abscess pockets in the left perirenal space, extending (more ...)
On the 12th day after admission, we conducted an ultrasonography-guided renal biopsy. The histology of the lesion showed a collection of foamy histiocytes also known as von Hansemann cells with von-kossa stain positive spheres (Michelis-Gutmann body) (). These findings are consistent with Malakoplakia. The patient presented dysuria and urgency, and antibiotic treatment was changed to oral ciprofloxacin (500 mg a day). On the 15th day after admission, she was discharged, as her presenting symptoms and laboratory findings were improved.
Figure 2 Renal biopsy (photomicrograph). (A) shows histiocytes with acellular basophilic precipitations (arrow) (H&E, ×400). (B) shows concentric, acellular basophilic precipitation (a.k.a Michaelis-Gutmann bodies) demonstrating calcium deposition (more ...)
About 4 months after discharge, the patient was readmitted presenting with general weakness for one month. The findings of the abdomen-pelvic CT conducted upon readmission () showed that the extent of the malakoplakia in the perirenal space had decreased since 9 week prior, as she had been taking the oral antibiotics. She has had follow-up in our outpatient clinic ever since, taking oral trimethoprim-sulfamethoxazole.