Spontaneous Retroperitoneal Hemorrhage Causing Page Kidney as the Initial Presentation of Clear Cell Renal Cell Carcinoma

Abstract

Spontaneous retroperitoneal hemorrhage is an uncommon presentation of renal pathology, and its association with Page kidney secondary to underlying renal cell carcinoma is exceedingly rare. We describe a 56-year-old man with no prior comorbidities who presented with acute abdominal pain, hemodynamic instability, and a significant hemoglobin drop. CT angiography revealed a massive left retroperitoneal hematoma measuring 16 × 12 × 32 cm, associated with Page kidney physiology, and a 7.7 × 8.6 × 8.7 cm exophytic complex hemorrhagic cystic lesion arising from the lower pole of the left kidney. Emergency super-selective angioembolization successfully controlled active bleeding. Serial imaging over subsequent weeks demonstrated hematoma regression and interval necrosis of the renal lesion without further contrast extravasation. Despite initial obscuration by hemorrhage, the lesion remained radiologically suspicious, prompting repeated multidisciplinary review. Functional studies showed preserved but reduced split renal function. Given persistent concern for malignancy, the patient underwent laparoscopic radical nephrectomy. Histopathology confirmed clear cell renal cell carcinoma with perinephric extension (pT3a) and no lymphovascular or nodal invasion. He was subsequently referred for adjuvant pembrolizumab therapy. This case underscores the importance of recognizing Page kidney in spontaneous renal hemorrhage, maintaining vigilance for occult malignancy, and adopting a staged multidisciplinary approach that prioritizes hemorrhage control while preserving oncologic decision-making.

Introduction

Page kidney refers to external compression of the renal parenchyma, most commonly by a subcapsular or perinephric collection, leading to renal hypoperfusion, activation of the renin-angiotensin-aldosterone system, and potentially secondary hypertension or renal dysfunction [1-4]. Although historically linked to trauma, contemporary reports show an increasing proportion of iatrogenic and spontaneous causes [3,4]. One important spontaneous presentation is Wunderlich syndrome, defined as nontraumatic spontaneous renal hemorrhage into the subcapsular and/or perirenal space [5]. Across meta-analyses and systematic reviews, renal neoplasms remain the leading cause of spontaneous perirenal hemorrhage, and a substantial proportion of these lesions are malignant, with renal cell carcinoma representing a major diagnosis to exclude [6,7]. CT is the key first-line imaging modality because it can confirm hemorrhage, assess hemodynamic severity, and identify an underlying renal lesion; however, the primary pathology may be partially masked at presentation by a large-volume hematoma or posthemorrhagic changes [5-8].

We report a rare case of the Page kidney phenomenon caused by spontaneous hemorrhage from an underlying clear cell renal cell carcinoma, initially stabilized by superselective angioembolization and subsequently managed with interval radical nephrectomy and referral for adjuvant immunotherapy.

Case presentation

A 56-year-old man with no known chronic medical illness presented to the emergency department with acute abdominal pain and an acute drop in hemoglobin. At presentation, he was tachycardic and hypertensive, with a blood pressure of 165/110 mmHg, a pulse rate of 136 beats/minute, a respiratory rate of 20 breaths/minute, a temperature of 36.7°C, and an oxygen saturation of 98% on room air. He was hemodynamically unstable and was transferred to the resuscitation area for supportive management, including fluid resuscitation and close monitoring.

On abdominal examination, the abdomen was soft and nondistended, with left flank tenderness; localized guarding was noted during the initial clinical assessment. Laboratory evaluation demonstrated an acute drop in hemoglobin, mild leukocytosis, normal inflammatory markers, and preserved renal function (Table 1).

Table 1. Laboratory investigations on presentation.

Parameter	Value	Reference range
Hemoglobin	11.7 → 10.2 g/dL	13.5-17.5 g/dL
WBC	12.8 × 10⁹/L	4.0-11.0 × 10⁹/L
CRP	1.3 mg/L	<3 mg/L
Procalcitonin	0.06 ng/L	<0.05 ng/L
Serum creatinine	0.9 mg/dL	0.6-1.2 mg/dL

Initial departmental ultrasonography was nonspecific apart from calcific densities in the left lumbar region. Evaluation with contrast-enhanced CT angiography of the abdomen subsequently demonstrated a large acute left retroperitoneal hemorrhage measuring approximately 16 × 12 × 32 cm, associated with the Page kidney phenomenon. In addition, the left kidney showed a large 7.7 × 8.6 × 8.7 cm exophytic complex hemorrhagic cystic lesion arising from the lower pole (Figure 1).

Figure 1. CT abdominal angiogram showing a large hyperdense retroperitoneal hematoma measuring 16 × 12 × 32 cm, occupying the lateral and anterior perinephric spaces and extending cranially to the subdiaphragmatic surface, as indicated by the arrow. In addition, a complex cystic exophytic mass measuring 7.7 × 8.6 × 8.7 cm can be seen arising from the lower pole of the kidney, marked by the circle and star.

The patient underwent emergency super-selective angioembolization for hemostatic control (Figure 2). Right femoral artery access was obtained using an 18-gauge needle to puncture the right common femoral artery, followed by insertion of a 5F sheath over a guidewire. Selective catheterization of the abdominal aorta and left renal artery was then performed. Left renal angiography demonstrated a large lower-pole renal mass supplied by multiple branches of the lower-pole artery, with evidence of active bleeding. Embolization of the supplying arteries was performed using 400- to 600-micron embolization particles, followed by coil embolization of the proximal lower-pole arterial branches using 5-6 mm coils. Post-embolization angiography demonstrated no further filling of the arterial supply to the lower-pole mass and no active bleeding. No immediate procedural complications occurred, and the patient was transferred to the high-dependency unit in stable condition.

Figure 2. (A, B) Primary feeding artery to the exophytic lesion, marked by an arrow, and the area of the lesion, indicated by a circle. (C, D) Successful post-embolization images.

Immediately after embolization, hemoglobin remained stable at 10.6 g/dL. His blood pressure improved to 112/79 mmHg, pulse rate was 119 beats/minute, respiratory rate was 20 breaths/minute, temperature was 37.3°C, and oxygen saturation was 97% on room air. During the inpatient course, there was a slight further decline in hemoglobin to 8.9 g/dL, for which he received one unit of packed red blood cells. At that time, his blood pressure was 128/77 mmHg, pulse rate was 114 beats/minute, temperature was 36.8°C, and oxygen saturation was 100%. Over the following days, hemoglobin improved to 10.1 g/dL.

Follow-up CT angiography performed during the early post-embolization period showed no contrast extravasation from the vessels or renal collecting system, with interval regression of the retroperitoneal hematoma (Figure 3). Gas locules were seen within the left renal mass, interpreted as post-embolization necrotic change. Subsequent staging CT imaging of the chest, abdomen, and pelvis showed no metastatic lesions. On later follow-up imaging, there was no ongoing leak, with mild regression of the retroperitoneal and perirenal hematoma and complete resolution of the gas locules within the complex left renal lesion.

Figure 3. CT angiogram post-embolization showing no active contrast extravasation from the vessels and evidence of super-selective embolization coils in place, marked by the arrow, with regression of the retroperitoneal hematoma.

The case was discussed in a multidisciplinary team meeting involving urologists, radiologists, pathologists, and oncologists. Because the initial posthemorrhagic and post-embolization appearance did not conclusively establish malignancy, ultrasound of the kidneys, ureters, and bladder (KUB) and dimercaptosuccinic acid (DMSA) renal cortical scintigraphy were recommended. DMSA demonstrated preserved right renal cortical function and a smaller left kidney with mildly reduced function; split renal function was 58% on the right and 42% on the left (Figure 4). Ultrasound KUB showed a regressing retroperitoneal bleed with a residual subcapsular hematoma extending toward the upper pole, measuring 9.6 × 5.3 × 8.7 cm (Figure 5A, 5B). Left renal parenchymal echogenicity and perfusion were preserved, while the exophytic complex hemorrhagic cystic lesion remained visible without appreciable internal vascularity.

Figure 4. DMSA scan indicating good cortical function of the right kidney and a smaller left kidney with slightly reduced function and slight cortical irregularity at the lateral aspect.

DMSA, dimercaptosuccinic acid

Figure 5. (A, B) Ultrasound follow-up showing a regressing retroperitoneal hematoma and an 8.3 × 7 × 7.1 cm exophytic complex hemorrhagic cystic lesion (encircled) in the lower pole of the left kidney without internal vascularity. (C) Contrast-enhanced CT showing a regressed retroperitoneal hematoma, with the arrow indicating endovascular embolization and the asterisk indicating the left renal complex cystic lesion. (D) Surveillance contrast-enhanced CT following left radical nephrectomy showing a clear operative bed with no recurrence or residual disease.

The patient was re-discussed at a subsequent multidisciplinary meeting, where the lesion was considered a large, high-risk complex renal mass, radiologically in keeping with Bosniak III/IV morphology. Repeat CT of the abdomen and pelvis with contrast showed broadly similar findings (Figure 5C). Two weeks later, the patient underwent laparoscopic left radical nephrectomy.

Histopathological examination confirmed clear cell renal cell carcinoma with extension into perinephric tissue beyond the renal capsule, without lymphovascular invasion or regional lymph node involvement, consistent with pT3a disease (Figure 6).

Figure 6. Histopathology of the radical nephrectomy specimen. (A) Low-power view (10×) showing capsular breach by clear cell renal cell carcinoma, indicated by the arrow. (B) Low-power view (10×) showing a clear cell tumor nest in the perirenal fat, indicated by the arrow. (C and D) High-power views (40×) showing sheets of tumor cells with clear cytoplasm and conspicuous eosinophilic nucleoli.

Following final pathology review at a third multidisciplinary meeting, the patient was referred to oncology and offered adjuvant pembrolizumab 200 mg every three weeks for 12 months, with surveillance CT staging (Figure 5D) and baseline laboratory follow-up, with an unremarkable clinical course.

Discussion

Page kidney was first described experimentally by Irvine Page and is now understood as renal parenchymal compression causing hypoperfusion, renin-driven hypertension, and, in some patients, impaired renal function [1-4]. In contemporary practice, Page kidney is no longer limited to blunt trauma; nontraumatic, postprocedural, and mass-related causes are increasingly recognized [3,4]. In our patient, the compressive effect of a very large retroperitoneal/perirenal hemorrhage created the Page phenomenon in the setting of a bleeding renal tumor rather than the more typical traumatic mechanism.

Spontaneous renal hemorrhage, often referred to as Wunderlich syndrome, is an uncommon but potentially life-threatening presentation that should always prompt investigation for an underlying cause [5,9]. The literature consistently shows that renal neoplasms are the most common etiologic category and that malignant tumors account for a substantial share of cases [6,7]. Zhang et al. found that neoplasms were responsible for most spontaneous perirenal hemorrhages in their meta-analysis, with renal cell carcinoma representing a major malignant source [6]. More contemporary systematic review data support the same principle: although management strategies have evolved, the need to exclude occult renal malignancy remains central [7]. This is particularly relevant when the initial scan is dominated by hematoma, clot, mass effect, and devascularization, all of which can reduce confidence in lesion characterization at the time of acute presentation.

The radiologic course in this patient also reflects a common diagnostic challenge. CT is the cornerstone of acute assessment because it rapidly identifies hemorrhage, estimates its extent, detects contrast extravasation, and surveys for an underlying renal lesion [5,8,9]. Nevertheless, CT sensitivity for identifying the precise etiology of spontaneous renal hemorrhage is imperfect, especially when large hematomas obscure enhancement patterns [6,8]. For that reason, repeat imaging after partial hematoma resolution is strongly supported in patients whose underlying pathology remains uncertain [6-8].

In the present case, early imaging demonstrated a hemorrhagic cystic lower-pole lesion, but the combination of acute bleeding and post-embolization necrosis initially limited radiologic certainty. Serial cross-sectional imaging, supplemented by ultrasound and DMSA functional assessment, allowed a safer and more confident transition from emergency hemorrhage control to definitive oncologic treatment.

Management in this setting must balance hemodynamic urgency against the risk of unnecessary emergency nephrectomy. Renal arteriography with selective embolization has become an important organ-directed strategy for acute hemorrhage control and can stabilize patients while preserving time for diagnostic clarification and multidisciplinary planning [5,7,9]. In our patient, super-selective embolization achieved prompt hemostasis and converted an unstable presentation into a controlled interval pathway. That approach was especially valuable because the lesion's malignant nature was not unequivocal immediately after the bleed.

This staged strategy aligns with contemporary practice, in which embolization is frequently used as first-line management for active renal bleeding, reserving surgery for persistent instability, nonsalvageable anatomy, or a confirmed or highly suspicious underlying neoplasm [5,7,9].

A further strength of this case is that it illustrates the relevance, but also the limitations, of cystic renal mass classification in the posthemorrhagic setting. The Bosniak version 2019 provides a standardized framework for estimating malignancy risk in cystic renal lesions based on imaging morphology [10]. However, acute hemorrhage and post-embolization changes can complicate the interpretation of septa, wall irregularity, and enhancement. Despite these limitations, repeated multidisciplinary review in our case appropriately maintained concern for a high-risk Bosniak III/IV lesion and supported definitive resection once the patient had stabilized. Final pathology confirmed clear cell renal cell carcinoma with extension into perinephric tissue beyond the renal capsule, corresponding to pT3a disease, thereby validating the cautious oncologic concern raised on interval imaging.

The postoperative management is also noteworthy. For patients with high-risk clear cell renal cell carcinoma after nephrectomy, adjuvant pembrolizumab has emerged as an evidence-based option. In KEYNOTE-564, adjuvant pembrolizumab improved disease-free survival after surgery, and later overall survival analysis further supported its role in this setting [11,12]. Given the patient's pT3a clear cell histology, referral for adjuvant pembrolizumab was appropriate and consistent with contemporary oncologic practice.

Overall, this case highlights three practical lessons. First, spontaneous retroperitoneal hemorrhage should not be considered a diagnosis in itself; it is often a manifestation of underlying renal pathology, including malignancy. Second, Page kidney can arise in the acute hemorrhagic setting and may coexist with preserved contralateral renal function, making recognition dependent on careful imaging interpretation rather than dramatic renal failure alone. Third, a staged multidisciplinary approach consisting of emergency embolization, interval reimaging, functional assessment, and delayed definitive nephrectomy can be both safe and oncologically sound when a renal mass is initially obscured by hemorrhage.

Conclusions

This case demonstrates a rare presentation of clear cell renal cell carcinoma as a spontaneous retroperitoneal hemorrhage complicated by the Page kidney phenomenon. The acute bleed initially obscured the underlying malignancy, making staged decision-making essential. Emergency super-selective angioembolization provided effective hemorrhage control and allowed interval reassessment, after which persistent concern for a high-risk renal mass led to radical nephrectomy and definitive diagnosis of pT3a clear cell renal cell carcinoma. Clinicians should maintain a high index of suspicion for occult renal malignancy in spontaneous renal hemorrhage and should consider repeat imaging and multidisciplinary review before concluding that posthemorrhagic lesions are benign.