A 34-year-old male with left loin pain and haematuria

A 34-year-old male presented with complaints of left loin pain for the past 1 month. The patient had insidious-onset left loin pain. It progressed gradually. It was not radiating to the groin. The pain was aggravated when he began to jog and go on a motorcycle ride. There was no history of fever or burning micturition. He had a history of episodic haematuria for the past 2 months. There was a history of loss of appetite and loss of weight. He has lost 10 kg in the past 3 months. He complained orthostatic nausea. He had a history of scrotal swelling on the left side for the past 3 months. He had no history of swelling of the lower limbs, breathlessness, cough or haemoptysis. There was no history of frothy urine, oliguria; hearing loss or blurring of vision; blunt trauma; or loose stools. There was no history of chest pain, palpitations or syncope. There was no histroy of diabetes mellitus or hypertension. He had no ischaemic heart disease, drug allergies, tuberculosis, seizures or stroke. He consumes a mixed diet, does not consume alcohol and is a non-smoker. He is married for 5 years, yet to have children. There is a history of painkiller usage for loin pain. On examination the patient was well built, ill-nourished, body mass index was 16 kg/m2; pulse 98/min, normal rate, rhythm, volume, character. There was no radio-radial or radio-femoral delay. All peripheral pulses were felt equally. Blood pressure was 110/70 mmHg. Abdominal examination was unremarkable except for a soft swelling in the left scrotal sac measuring 4 cm × 3 cm. There was no local tenderness or rise in the temperature. There were no sinuses and no scars. Testicular sensation was intact. Cardiovascular, respiratory and neurological examination were normal. Laboratory investigations are summarised in Table 1.Table 1: Laboratory investigationsDIFFERENTIAL DIAGNOSIS The differential diagnoses of this triad of symptoms fall into three categories (Table 2).Table 2: Differential diagnosis of loin pain, haematuria and scrotal swellingThe causes of exertion-induced left loin pain (exercise-related transient abdominal pain) are diaphragmatic ischaemia, stress on ligaments supporting diaphragm, splenic 9 infarction, intestinal ischaemia, obstructing nephrolithiasis, left renal vein (LRV) entrapment and loin pain haematuria syndrome (LPHS). The patient had complained orthostatic nausea, which is a part of orthostatic intolerance. The other symptoms of this syndrome include light headedness, dizziness, blurring of vision, generalised weakness, fatigue, palpitations, mental clouding, anxiety, dyspnoea and headache. The differential diagnosis at the end of the history is given in (Table 3).Table 3: Differential diagnosis at the end of the historyThe systemic examination and investigations revealed a 4 cm × 3 cm scrotal swelling present in left scrotal sac, no local tenderness/rise in temperature and the presence of red blood cells in urine. With these findings, the diagnosis of a few conditions could be ruled out. Chronic epididymo-orchitis requires the presence of local tenderness, scars and sinuses and Prehn's sign needs to be positive. Testicular cancer requires intact testicular sensation. As its absence was not mentioned, it was presumed to be intact. Varicocele could have had dilated pampiniform plexus of veins on standing and reduced on lying down. The absence of sinuses and scars ruled out tuberculosis (TB). Normal eye and ear examination excluded Alport's syndrome and the absence of palpable renal cysts had excluded autosomal dominant polycystic kidney disease. The absence of eosinophilia argues against schistosomiasis. However, additional information is required to confirm the following conditions, even though with the available information, these conditions could reasonably be ruled out. The conditions are tuberculosis (needs imaging), immunoglobulin A nephropathy, thin basement membrane disease (needs renal biopsy), Alport's syndrome (needs slit lamp examination), obstructive nephrolithiasis (needs imaging) and sickle cell trait/disease (needs osmotic fragility test and peripheral smear). Pending the above investigations, the differential diagnoses which should be considered are LRV entrapment (nutcracker syndrome [NCS]) and loin pain haematuria syndrome. The LPHS was first described in 1967 in a report of three young women (20–28 years of age) who had recurrent episodes of severe unilateral or bilateral loin (flank) pain that was accompanied by gross or microscopic haematuria.[1] The major causes of flank pain and haematuria, such as nephrolithiasis and blood clots, were not present. Renal arteriography suggested focally impaired cortical perfusion, while kidney biopsy showed interstitial fibrosis and arterial sclerosis.[1] RADIOLOGIST'S DIAGNOSIS The colour doppler ultrasonography of the left kidney showed normal colour uptake in intrarenal arteries and veins, at the level of renal hilum (Figure 1). The colour doppler ultrasonography findings are shown in Figures 1 and 2. On contrast-enhanced computed tomography (CECT) revealed aortomesenteric angle (AMA) was 13.6° (Figure 3). The computed tomography (CT) abdominal angiogram in the portal venous phase showed compression of LRV between the aorta and SMA suggestive of, the "beak sign" (Figure 4). The beak angle (angle 2 in the Figure) was 49° (Figure 5). On axial CT imaging, the compression ratio was 3.6 (Figure 6). Axial CECT showed normal calibre of bilateral gonadal veins (Figure 7) normal scrotal sac and no focal lesions and no evidence of varicocele (Figure 8).Figure 1: Colour Doppler ultrasonography image of the left kidney showing normal colour uptake in intrarenal arteries and veins, at the level of renal hilumFigure 2: Colour Doppler ultrasonography axial image at the level of superior mesenteric artery (SMA) (orange arrow), showing compression of left renal vein (white arrow) between aorta (green arrow) and SMA. Left renal vein is increased incalibre, proximal to the site of compressionFigure 3: CECT abdomen (sagittal section) showing aortomesenteric angle (circle) (labelled as 1) = 13.6°CECT=contrast--enhanced computerised tomographyFigure 4: Computed tomography abdominal angiogram (axial section), portal venous phase, showing compression (red arrow) of left renal vein between aorta (A) and superior mesenteric artery (SMA), suggestive of the "beak sign"LRV = Left renal veinFigure 5: CECT abdomen (sagittal section) showing beak angle (labelled as 2) = 49°CECT=contrast--enhanced computerised tomographyFigure 6: Contrast-enhanced computed tomography of abdomen showing ratio of precompressed vein (P) divided by that of the compressed vein (C) = 3.6Figure 7: CECT abdomen showing normal calibre of bilateral gonadal veins (yellow circles)CECT=Contrast enhanced computed tomographyFigure 8: CECT abdomen (axial section) showing normal scrotal sac. There are no focal lesions or evidence of varicocelCECT=Contrast enhanced computed tomographyImaging features are consistent with "nutcracker phenomenon".[1-6] The term "nutcracker phenomenon" has been used to refer to compression of the LRV which can occur primarily in two anatomic locations (Table 4). Anterior nutcracker phenomenon, is the classical variety that occurs at the branching of the SMA from the aorta. Posterior nutcracker phenomenon is the rarer form where in a retroaortic left renal vein is compressed between the aorta and vertebrae; rarely, a mixed form can occur.[1-6] Imaging criteria for the diagnosis of nutcracker phenomenon are an AMA lower than 35° (normal range = 38° to 65°) with evidence of beak sign on axial image (which represents stenosis of the LRV between the aorta and the SMA).[6]Table 4: Diagnostic criteria for nutcracker phenomenon[ 2-5 ]FINAL DIAGNOSIS Nutcracker syndrome (NCS) which is nutcracker phenomenon coupled with clinical symptoms. We suspected nutcracker phenomenon as the patient complained of worsening loin pain with physical activity. The symptoms of episodic haematuria and scrotal swelling on the left side are further directed towards the nutcracker phenomenon. The NCS is the clinical equivalent of nutcracker phenomenon characterised by a complex of symptoms with substantial variations. Although some patients have severe and persistent symptoms, many, especially children, are asymptomatic.[7-9] The symptoms are often aggravated by physical activity[10] and commonly include haematuria, pain or gonadal vein syndrome,[10,11] varicocele[10-13] and orthostatic proteinuria.[14-22] Varicoceles almost always occurs on the left side and affects up to 9.5% of men.[6] The LRV was compressed in 50% to 100% of all patients with varicocele,[12,23] although not all patients with varicocele have a distended LRV.[13,24] The alternatives for the treatment include the options from observation to nephrectomy. For mild haematuria, conservative treatment is recommended.[23,25] The conservative approach with observation for at least 2 years is recommended for patients younger than 18 years because as many as 75% of patients will have complete resolution of haematuria.[8,26-28] Angiotensin inhibitors may be help to reduce orthostatic proteinuria.[17,18,21] The interventions should be considered carefully, only when symptoms are severe or persistent, such as severe unrelenting pain, severe haematuria, renal insufficiency and failure to respond to conservative treatment after 24 months.[29-33] The caution is necessary because the correlation between imaging evidence of LRV compression and clinical symptoms remains weak. A few surgical approaches are medial nephropexy with excision of renal varicosities,[10] LRV bypass,[11] LRV transposition with or without Dacron wedge insertion between SMA and aorta,[29,32-37] SMA transposition,[37,38] renal-to-inferior vena cava shunt,[35] renal autotransplant,[32,39,40] gonadocaval bypass[41] and even nephrectomy for persistent haematuria.[29] In addition, external stunting with ringed polytetrafluoroethylene graft interposition around the LRV[42] and intravascular stunting have been applied relatively recently. Both balloon-expandable and self-expanding stents have been used in adult and paediatric patients.[28,37,42-50] Both the surgery and stent relieve the symptoms but the selection criteria are not well-defined. We treated this patient with reassurance and angiotensin-converting enzyme inhibitors. He is on regular follow-up. 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.