
==== Front
Indian J Nucl Med
Indian J Nucl Med
IJNM
Indian J Nucl Med
Indian Journal of Nuclear Medicine : IJNM : The Official Journal of the Society of Nuclear Medicine, India
0972-3919
0974-0244
Wolters Kluwer - Medknow India

IJNM-39-227
10.4103/ijnm.ijnm_25_24
Interesting Image
An Interesting Image of Carcinoma Breast with Renal Calyceal Diverticulum Mimicking Renal Metastasis on [18F]FDG PET/CT Scan
Bukke Surekha
Gavini Surya
Priya Rallapeta Ramya
Dhamarcherla S Hemalatha
Devi Bodagala Vijalakshmi 1
Kalawat Tekchand
Department of Nuclear Medicine, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India
1 Department of Radiology, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India
Address for correspondence: Dr. Tekchand Kalawat, Department of Nuclear Medicine, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India. E-mail: kalawat.svims@gmail.com
May-Jun 2024
17 8 2024
39 3 227228
26 2 2024
12 3 2024
14 3 2024
Copyright: © 2024 Indian Journal of Nuclear Medicine
2024
https://creativecommons.org/licenses/by-nc-sa/4.0/ This is an open access journal, and articles are distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as appropriate credit is given and the new creations are licensed under the identical terms.
A diverticulum is an outpouching of a hollow (or fluid-filled) structure in the body. They are most commonly seen in the urinary bladder, intestine, and pharyngeal region and are rarely seen in renal calyces. They are usually benign, asymptomatic, and are coincidentally detected. Due to their nonspecific clinical and radiological picture, sometimes they mimic malignant tumors, leading to misdiagnosis and treatment. We are presenting a case of 60-year-old female with right breast carcinoma, on whole body 18-fluorodeoxyglucose positron emission tomography-computed tomography; we observed an interesting finding in the right renal region mimicking renal metastasis.

18-fluorodeoxyglucose positron emission tomography-computed tomography scan
calyceal diverticulum
mimicking renal metastasis
==== Body
pmcPyelocalyceal diverticulum is an outpouching of renal calyx into the renal cortex, through narrow channel connecting with the central collecting system. They may be empty or filled with urine, stone, or calcium. It is most commonly congenital in origin with slight female preponderance.[1] Although they are usually asymptomatic, complaints of hematuria, flank pain, and urinary tract infections were also documented.[2] Diagnosis is usually made radiologically through modalities such as intravenous urograms and contrast-enhanced computed tomography (CECT), which demonstrates a lesion that connects with the pelvicalyceal system through an infundibulum and shows contrast fill-in during the excretory phase. Ultrasonography shows anechoic lesions with mobile hyperechogenic material within the diverticulum.[34]

In 18-fluorodeoxyglucose positron emission tomography examination, through physiological excretory route through the renal system, radiotracer accumulation would be seen in the diverticulum, and could be misinterpreted as renal neoplasm or metastasis leading to mismanagement.[5] However, such lesions will show washout of radiotracer on dual point imaging, and diagnosis would be confirmed by careful anatomical correlation as shown in Figure 1. Similar presentations were documented by Wang et al. and Kavanagh et al.[67] As in our case, delayed contrast filling in CECT aided in confirming the presence of benign calyceal diverticulum.

Figure 1 (a) 18-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) maximum intensity projection image shows abnormal FDG avidity in the right hemithorax that corresponds to metabolically active mass lesion in the right breast. Coronal sections (b) PET (c) contrast-enhanced computed tomography (CECT) (d) Fused PET-CT images show focus of FDG avidity in hypodense lesion in right kidney upper pole (green arrows), measuring 3.1 cm × 2.7 cm with maxSUV: 8.8. Delayed axial sections (e) PET (f) CECT (g) Fused PET-CT images show washout of radiotracer and diffuse contrast filling confirming diagnosis of calyceal diverticulum

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.
==== Refs
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