The first observation on the solitary ectopic pelvic kidney was made by Henot in 1830. It was made on an autopsy of 8 months of age whose sex was indefinite owing to the absence of the genitalia [10]. Necropsy records were derived from many sources which had indicated that ectopic kidney is found once in from 2150 to 3000 [11]. There are many factors that inhibit the kidney from gradual ascend to the abdomen and away from the midline. The factors can be in the form of ureteral bud maldevelopment, defective metanephric tissue, genetic abnormalities, maternal illness and teratogenic causes [12]. Clinically the renal ectopia is more readily recognized in females because they undergo uro-radiological evaluation more frequently than that of males. As a result of which, a higher rate of urinary tract infection gets associated with genital anomalies [13]. Ectopic kidneys are usually smaller than the normal size of kidneys. The renal pelvis is usually anterior to the parenchyma because it is incompletely rotated. It has been observed that the major portion of the ectopic kidneys is clinically asymptomatic. Ectopic kidneys are no more susceptible to disease than normal. Exceptions are there such as hydronephrosis development, renal stones formation, and urinary tract infections [14].
In our case, the unnecessary surgical operation was avoided by just 2 min. With the implementation of POCUS and diagnosis, it was confirmed that CT abdomen with IV contrast. Ultrasound can recognize the ectopic kidney by its overall similarity in shape, size and structure to normal kidneys. However, the pelvic kidneys might get developed with unusual shapes and degrees of rotation can form. Moreover, it may show some dilatation of the collecting system [15]. These unusual features may make an ectopic kidney difficult to recognize as a kidney, especially if an unexpected finding is observed which might present a mass during an examination. This can be highly confusing, as it can have similarities with appendicular mass, bowel tumors, and pelvic lymphadenopathy. Here the color Doppler is of great value as it demonstrates a normal vascular architecture that is compatible with renal vessels [16] (Fig. 4).
Both POCUS and abdominal helical computed tomography (CT) are essential tools in managing the patient who is affected with acute abdominal pain in the emergency department. Both are considered to have acceptable sensitivities, specificities, and positive and negative predictive values. It has been regarded that CT to be more superior in numerous studies [17]. Although with the advantage of the high sensitivity of abdominal CT, there are mainly three disadvantages of the abdominal CT. The first is exposing the patient to the risk of ionizing radiation, with an estimated 2% of future cancers being triggered just by CT scans [18]. The second disadvantage is that the CT abdomen is highly expensive and is not accessible in all medical providing institutions primarily in developing countries. Finally, prolonged emergency department stays when CT abdomen order with oral and/or rectal administration. It has also been inculcated that there is a risk of allergic reaction and nephrotoxicity from IV contrast administration. The advantages of the POCUS are lack of ionizing radiation, noninvasive, simple to handle, document the entire ultrasound finding, widely available, real-time imaging, portable and cheap. Furthermore, repetitive ultrasound examinations can be done easily simultaneously which leads to enhancing clinicians’ ability to perform serial reassessments and assists in further management. POCUS is recognized to be useful in children and pregnant patients and is one of the principal modality for these patients based on the American College of Radiology guidelines [19]. The disadvantages are decrease sensitivity, lack of operator experience, patient factors like obesity. A few of the other disadvantages can be superimposed bowel gas or typically located appendix. There can also be greater pain during the application of the graded compression process. Poortman et al. [20] concluded that a diagnostic pathway includes the initial US and complimentary CT in patients with negative or inconclusive US. The results yield high diagnostic accuracy in the management of acute appendicitis without adverse events.