Journal of Indian Association of Pediatric Surgeons
Journal of Indian Association of Pediatric Surgeons
                                                   Official journal of the Indian Association of Pediatric Surgeons                           
Year : 2023  |  Volume : 28  |  Issue : 1  |  Page : 75--79

Frozen section biopsy and nephron-sparing surgery for a multiloculated cyst of the kidney; Is this the ideal approach?

M Aditya1, Sujit K Chowdhary1, Vikas Kashyap2,  
1 Department of Pediatric Urology and Pediatric Surgery, Indraprastha Apollo Hospitals, New Delhi, India
2 Department of Histopathology, Indraprastha Apollo Hospitals, New Delhi, India

Correspondence Address:
Sujit K Chowdhary
Department of Pediatric Urology and Pediatric Surgery, Indraprastha Apollo Hospitals, Sarita Vihar, New Delhi - 110 044


Multiloculated cystic renal masses are uncommon in the pediatric population. The presentation may be as an asymptomatic incidental finding on imaging, abdominal mass, abdominal pain, or urinary tract infection. The differentiation between benign and malignant causes of a cystic lesion by clinical and radiological examination is difficult. Tru-cut biopsy is not recommended due to fear of upgrading a malignant tumor. A definitive diagnosis is confirmed histopathologically only after surgery. Based on certain imaging characteristics, benign nature can be suspected and a conservative approach to surgery can be contemplated to save the kidney. Frozen section biopsy is useful in ruling out malignancy while doing nephron-sparing surgery (NSS) in these patients. NSS may be done by an open or minimally invasive approach. After histological confirmation of cystic nephroma, no other adjuvant treatment is necessary, but long-term surveillance is strongly recommended.

How to cite this article:
Aditya M, Chowdhary SK, Kashyap V. Frozen section biopsy and nephron-sparing surgery for a multiloculated cyst of the kidney; Is this the ideal approach?.J Indian Assoc Pediatr Surg 2023;28:75-79

How to cite this URL:
Aditya M, Chowdhary SK, Kashyap V. Frozen section biopsy and nephron-sparing surgery for a multiloculated cyst of the kidney; Is this the ideal approach?. J Indian Assoc Pediatr Surg [serial online] 2023 [cited 2023 Mar 28 ];28:75-79
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The contemporary practice of diagnosing and treating renal tumors of unknown etiology, particularly multiloculated cystic renal tumor (MLCRT) has remained controversial. Despite many combinations of treatments proposed, recent series reported from India have recommended radical nephrectomy (RN).[1],[2] Authors report a successful outcome with a minimally invasive approach (robotic) in such a lesion and discuss the appropriate and ideal approach for polar lesions of the kidney, i.e., a multilocular cyst.

 Case Report

A 7-year-old female child presented with intermittent episodes of high-grade fever and left flank pain for 2 months. Abdominal examination revealed left flank and left renal angle tenderness. contrast-enhanced computed tomography showed a Bosniak Type III large complex cyst measuring 6.3 cm × 6.1 cm × 6 cm arising from the upper pole pushing the hilum anteriorly, with internal septations and septal calcification, with no solid component or fat content [Figure 1].{Figure 1}

She was initially treated in a teaching hospital as a renal abscess with 2 weeks of intravenous culture-sensitive antibiotics, following which her fever resolved. When the symptoms recurred after a month, she was advised to undergo a total nephrectomy. She then came to us for a second opinion. On reviewing the case, we have considered MLCRT, infective pathologies such as a renal abscess, or xanthogranulomatous pyelonephritis (XGPN) as differential diagnoses and planned for intraoperative frozen section biopsy and robotic left partial/total nephrectomy.

On robotic exploration following retrograde pyelogram and Double J stenting, the lesion was seen involving the left renal upper pole with omentum and splenic flexure densely adhered to it. The lesion was seen extending up to the renal pelvis, but no communication was noted. Robotic-assisted partial nephrectomy was done with a rim of the normal renal parenchyma. Frozen section of the lesion was done which showed chronic inflammatory infiltrates with no evidence of malignancy. Hence, the surgery was concluded. Postoperative recovery was uneventful without any urinary leaks.

The histopathological examination showed benign multiloculated cystic neoplasm, lined with cytologically bland cuboidal epithelium. Intervening fibrous septae showed chronic inflammatory infiltrates with no blastemal, nephrogenic rests, or epitheloid cell granulomas. At interphase with a normal band of renal parenchyma, there were varying degrees of atrophy due to compression by the lesion. These features prove the diagnosis of cystic nephroma with surrounding chronic tubulointerstitial nephritis [Figure 2].{Figure 2}


Renal tumors may appear in atypical presentation with imaging suggestive of the multiloculated cystic lesion. While the majority are benign, malignant cystic Wilms' tumor (CWT) is well known.[3],[4] While RN is a safer long-term option, partial nephrectomy nephron-sparing surgery (NSS) may be an equally good option with the scope of renal preservation. The widespread availability of frozen section biopsy and minimally invasive NSS makes it an attractive and perhaps an ideal approach as a treatment option instead of RN.

Multiloculated cystic nephroma and its differentials

Multilocular cystic nephroma (MLCN) usually presents in children between 3 months and 4 years of age with a male predominance (2:1).[5] They can involve any pole of the kidney with equal incidence on right and left kidney. It is the benign end of the spectrum of MLCRT including cystic partially differentiated nephroblastoma (CPDN) and CWT.[4],[6],[7]

Powell et al.[8] established the diagnostic criteria for MLCN as a unilateral, solitary, noncommunicating, multilocular cystic lesion lined by epithelium, with no renal parenchyma or blastemal cells in the intralocular septa and normal surrounding renal tissue. The presence of blastemal cells in the septa makes it CPDN. The presence of blastemal cells and solid components with or without stromal/epithelial elements makes it CWT. The presence of normal renal parenchyma between the cysts makes it a localized renal cystic disease.[3],[9] Focal XGPN is another close differential with a similar presentation and imaging, confirmed by cystic necrosis of renal parenchyma replaced by lipid-laden foam cells.[10]

Soft pointers in imaging

Cystic Wilms' tumor

There are solid components present within the mass.

Multilocular cystic nephroma/cystic partially differentiated nephroblastoma

It is not possible to differentiate them by imaging. Both of them are well-circumscribed, encapsulated with septations, but no solid components. Surrounding renal parenchyma is effaced with claw sign present. There can be displacement of the rest of the kidney.

Focal XNPG

It is indistinguishable from MLCN by imaging.[10]

Localized renal cystic disease

Cysts localized to one region of the kidney with intervening normal renal parenchyma. They lack a capsule. There is no displacement of the rest of the kidney.[3]

Distinguishing a malignant mass from a benign lesion is not possible with the imaging findings alone. The absence of solid elements with the presence of homogeneous renal tissue suggests the benign nature of the lesion and whenever possible should undergo conservative excision.[11]

Pitfalls of preoperative tissue sampling

Fine needle aspiration cytology of the cyst has low sensitivity and a high false-positive rate of malignancy.[1],[12] Trucut biopsy of such cystic lesion is contraindicated as it may lead to rupture of the cyst with tumor spill and upstaging of the disease.[5],[13]

Role of frozen section biopsy

Frozen section biopsy becomes significant whenever NSS is contemplated to rule out the possibility of malignancy in the excised specimen.[5],[9],[14] The diagnostic accuracy of frozen section biopsy ranges from 81% to 97% in the literature.[15] It is typically performed in a small portion of the specimen, especially any solid mural nodules along with parts of the cyst wall are sampled thoroughly and examined.[15] If malignancy is detected, then total nephrectomy is done in the same sitting avoiding a second surgery.

Treatment guidelines and role of nephron-sparing surgery

In such a case of the multiloculated cystic renal lesion, upfront surgery is advised with no tumor spill and avoiding unnecessary preoperative chemotherapy.[2],[13],[16] On reviewing the literature [Table 1], total/RN was done in around 80% of the cases, while only 18.5% underwent NSS.[11],[17] Complete excision without rupture of the cysts is mandatory and adequate treatment in such patients.[2],[5] There is a definite role of NSS whenever possible.[6],[11],[14],[18],[19] A minimally invasive approach may be considered for doing NSS.[20]{Table 1}

After NSS and histological confirmation, MLCN and Stage 1 CPDN does not require any adjuvant treatment, while higher stages of CPDN and CWT patients require adjuvant treatment.[2],[13],[16]

Follow-up of multilocular cystic nephroma

They are known to be associated with Wilms' tumor in the same or contralateral kidney and other secondary tumors such as pleuropulmonary blastoma, rhabdomyosarcoma, neuroblastoma, and anaplastic sarcoma.[14],[17] Rarely, recurrence or malignant transformation is reported in 3.4% of cases mandating long-term surveillance of these patients.[11],[17],[21]


Upfront NSS should be attempted in all complex cystic renal lesions, whenever possible, with the aid of frozen section biopsy to rule out malignancy intraoperatively. This may be done by open surgery or a minimally invasive approach. There is a limited role for preoperative tissue sampling. Long-term surveillance is recommended in all these patients.

Declaration of patient consent

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

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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