Renal abscess with paranephric extension in a gravid woman: Ultrasound and magnetic resonance imaging findings

Abstract

We present a case of renal abscess with perinephric and paranephric extension. Ultrasonography showed an intrarenal lesion. The extension into the perinephric and paranephric space was better defined on MRI.A 30-year-old woman at 25 weeks gestation was transferred for evaluation of a left renal mass. She presented to the emergency department with a 1-week history of left flank pain, which was exacerbated following a fall. On physical examination, she was afebrile and was markedly tender in the left renal flank.Microscopic urinalysis revealed 10-100 × 10 6 /L white blood cells. There was no bacterial growth on urine culture.Ultrasonography showed a complex, vascular mass measuring 11 × 6.5 cm arising from the mid to lower pole of the left kidney ( Fig. 1).As the nature of the mass was indeterminate, an MRI scan was performed at 27 weeks gestation. Axial T1-weighted gradient echo (Fig. 2a), axial T2 half-fourier acquisition single shot turbo spin echo, coronal T2 turbo spin-echo with fat suppression (Fig. 2b) and 2-D true free induction steady precession of the inferior vena cava (IVC) and renal veins were performed. Magnetic resonance imaging showed an enlarged heterogeneous mass arising from the mid and lower pole of the left kidney measuring approximately 12.0 cm in length, 8.0 cm in width and 8.5 cm in anteroposterior dimension. The mass was of both intermediate-and low-signal intensity in the T1-weighted acquisition and heterogeneous high-signal intensity in the T2-weighted sequences. The left kidney was displaced superiorly and anteromedially, and the tail of the pancreas was displaced anteriorly. There was mild dilatation of the left upper pole collecting system. The left quadratus lumborum and iliopsoas muscle showed high-signal intensity in the axial T2 and intermediate-to low-signal intensity in the T1-weighted sequences. There was loss of the fascial plane between the left renal mass and the paraspinal muscle. The M Puvaneswary MB BS, FRCR; A Bisits MB BS, FRANZCOG, Dip Clin Epi, M Med Stat; B Hosken MB BS, BSc, FRACS.Fig. 1. Ultrasound shows a large heterogeneous mass arising from the mid and lower pole of the left kidney.

Absceso renal en el embarazo

“…Dos casos reportados en la literatura de absceso renal en el embarazo detallan la presentación clínica del cuadro, siempre muy inespecífica. En un caso reportado en Australia en 2003, sobre una mujer de 30 años cursando un embarazo de 25 semanas, al momento de consultar la paciente refería historia de una semana de dolor en flanco izquierdo; al examen físico estaba afebril con puñopercusión positiva a izquierda, orina completa compatible con ITU y urocultivo negativo, realizándose posteriormente el diagnóstico definitivo con RM (3).…”

“…Esto fue descartado por aspiración percutánea, quedando con el diagnóstico definitivo de absceso renal. Se planteó realizar drenaje pero inició trabajo de parto por lo que finalmente se realizó posterior a éste, sin incidentes (3). En el reporte brasilero, dado que se trataba de un embarazo de término, con la paciente febril, leucocitosis de 14.000 /mm 3 y PCR aumentada (8,75 mg/dL) se decide iniciar tratamiento endovenoso con ampicilina e inducir el trabajo de parto.…”

“…El desarrollo del absceso renal durante el embarazo es excepcional, pese a que la prevalencia de la ITU aumenta con la gestación (10-15% de las gestantes) y que el 75% de los abscesos renales son secundarios a la infección (2,3).…”

Dynamic magnetic resonance imaging in acute pyelonephritis

“…Among male subjects, mean age was higher (55.33 years), presumably coinciding with the onset of prostatic hyperplasia, a cause of urinary stasis and possible risk factor for the pyelonephritic process [9]. Nevertheless, in one case of APN arising during pregnancy, unenhanced MRI [9,20] provided an additional diagnostic tool to ultrasound. In this case, the signal alterations seen on baseline scans were alone sufficient to confirm the clinical and sonographic suspicion, despite the limited accuracy of baseline scans.…”

“…Nella popolazione maschile l'età media è risultata superiore (55,33 anni), coincidendo più verosimilmente con l'insorgenza di iperplasia prostatica che, causando stasi urinaria, è considerata un fattore favorente il processo pielonefritico [9]. Non di meno, anche in un episodio di PNA insorta durante la gravidanza, l'RM senza mezzo di contrasto [9,20] (27,2%) dei pazienti con PNA. La riduzione o scomparsa del gradiente cortico-midollare è stata osservata solo nel 7,2% dei casi (per lo più associata -6/9 casi -a quadri di PNA più severi, complicati con segni di ascessualizzazione), in accordo con il dato che si tratta comunque di reperti incostanti, non patognomonici della malattia [6].…”