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Year : 2016  |  Volume : 4  |  Issue : 1  |  Page : 27-29

Urinothorax: An uncommon case of pleural effusion

1 Department of Pulmonary Medicine, Ispat General Hospital, Rourkela, Odisha, India
2 Department of Surgery, Ispat General Hospital, Rourkela, Odisha, India
3 Department of Radiology, Ispat General Hospital, Rourkela, Odisha, India
4 Department of Infectious Disease Biology Unit, Institute of Life Sciences, Bhubaneshwar, Odisha, India
5 Department of Molecular and Immunology Laboratory, Ispat General Hospital, Rourkela, Odisha, India

Date of Web Publication23-Dec-2015

Correspondence Address:
Anita Mohanty
Department of Pulmonary Medicine, Ispat General Hospital, Rourkela - 769 005, Odisha
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/2320-8775.172480

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Urinothorax is classically described as the formation of urinoma as a result of retroperitoneal leakage and accumulation of urine in the pleural cavity. Since respiratory manifestations could be uncommon or rare and dominated by urological signs, which could be due to secondary or obstructive uropathy; the diagnosis of urinothorax warrants high clinical suspicion. We report such an uncommon case of urinothorax in a patient with chronic kidney disease admitted to a tertiary industrial hospital and treated successfully. Increased awareness among the physicians of such a rare clinical entity may facilitate prompt diagnosis and appropriate clinical management.

Keywords: Chronic kidney disease, pleural effusion, urinothorax

How to cite this article:
Mohanty A, Rao C M, Rath B, Sarkar B, Majhi M, Panda P, Chattopadhyay S, Mohanty AK, Sahu PK. Urinothorax: An uncommon case of pleural effusion. J Assoc Chest Physicians 2016;4:27-9

How to cite this URL:
Mohanty A, Rao C M, Rath B, Sarkar B, Majhi M, Panda P, Chattopadhyay S, Mohanty AK, Sahu PK. Urinothorax: An uncommon case of pleural effusion. J Assoc Chest Physicians [serial online] 2016 [cited 2021 Dec 7];4:27-9. Available from: https://www.jacpjournal.org/text.asp?2016/4/1/27/172480

  Introduction Top

Urinothorax is an infrequent cause of pleural effusion. It is defined as presence of urine in pleural space. The condition is due to the retroperitoneal leakage of urine leading to urinoma formation. The urine then passes into the pleural cavity through an anatomical defect in diaphragm or via lymphatic system.[1] Such diagnosis requires a high degree of clinical suspicion as the respiratory symptoms tend to be absent or mild and urological signs tend to dominate. It is usually secondary to obstructive uropathy or traumatic (iatrogenic) injury of the urinary system.[2]

  Case Report Top

A 64-year-old male, presented with chief complaints of insidious onset, gradually progressive breathlessness of Modified Medical Research Council grade III and persistent dry cough for 7 days. There was no history of fever, chest pain, hemoptysis, wheezing, palpitation, swelling of feet or alteration of speech. He had undergone excision of right upper pole renal mass 1 month back, which was closed with perinephric fat and double-J (D-J) stenting. Histopathology of the mass was suggestive of infective etiology and postoperative period was uneventful. He was a known hypertensive and chronic kidney disease (CKD) for 3 years. On general examination, he was conscious, oriented with normal built. There was no pallor, icterus, cyanosis, clubbing, or edema feet. Jugular venous pressure was not raised and no palpable lymphadenopathy.

His pulse was 86/min, the temperature was normal, SpO2 was 96%. There was a 10 cm horizontal scar mark over right lumbar region posteriorly due to a surgical procedure for renal mass. On lower respiratory tract examination, there was markedly decreased breath sound on right-side of the chest with the shifting of apex beat and trachea to left, suggestive of pleural effusion. No abnormality was detected on other systemic examination. The chest radiograph (CXR) a s shown in [Figure 1]a, revealed right-sided massive pleural effusion. His hemogram was normal with hemoglobin - 11.3 g%, total leucocyte count - 6400/mm 3 (neutrophil-59; eosinophil-4; lymphocyte-30; monocyte-7; basophil-0) platelet - 340000/mm 3, erythrocyte sedimentation rate - 15 mm. Among the biochemical parameters, fasting blood sugar - 101 mg%, serum sodium - 143 mml/L, serum potassium - 3.9 mml/L, serum urea - 72 mg%, serum creatinine - 3.1 mg%, serum protein - 6.8 g%, serum albumin - 4 g%, serum lactate dehydrogenase (LDH) - 304 U/L, electrocardiogram -normal. Thoracocentesis was performed which yielded 3.5 L of straw-colored fluid with distinctive smell and look of urine [Figure 1]b. Pleural fluid analysis revealed protein of 3.6 g%, glucose of 122 mg%, LDH was 278 U/L with cellularity of 50 cells/mm 3 out of which mononuclear cells were 98% and polymorph of 2%, few mesothelial cells and no malignant cells were seen. The bacteriological examination of the fluid revealed no micro-organism in Gram's stain and no acid-fast bacilli in Ziehl–Neelsen stain. The fluid culture was negative. Pleural fluid adenosine deaminase was 17.3 U/L.
Figure 1: (a) CXR-showing right sided massive pleural effusion; (b) aspirated pleural fluid; (c) CXR-PA view (right sided ICT in situ;) (d) USG of thorax showing pleural effusion

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The serum to pleural fluid protein gradient was > 3.1 g/dL, which implies a transudate. Further analysis of pleural fluid, showed a urea level of 73 mg% and pleural fluid creatinine of 4.9 mg%. The serum urea was 72 mg% and serum creatinine was 3.1 mg%. Pleural fluid creatine to serum creatinine ratio was more than one. So it was a case of urinothorax probably as a complication of renal surgery. Due to the rapid and recurrent collection of pleural fluid, inter-costal tube drain (ICTD) was inserted [Figure 1]c. Further investigation was done in the form of ultrasonogram (USG) and computed tomography (CT) scans. USG of thorax revealed right-sided pleural effusion [Figure 1]d. USG of the abdomen revealed bilateral (B/L) renal parenchymal disease and an abnormal communicating tract was suspected [Figure 2]a and hence CT scan of the abdomen was advised. As the patient was a case of CKD, intravenous contrast could not be given, but noncontrast computed tomography (NCCT) revealed the communication between the retroperitoneal urinoma and the right pleural cavity [Figure 2]b and [Figure 2]c. No other mass lesion was detected in CT thorax and CT abdomen [Figure 3]a and [Figure 3]b. It was decided to observe the patient until pleural fluid was drained completely; a decision based on the radiological anatomy of the tract. The patient was discharged with ICTD in situ. ICTD was removed after 3 weeks as there was no more drainage in last 3 days. Repeat CXR showed almost resolution of the effusion [Figure 3]c.
Figure 2: (a) USG of abdomen showing suspected communication; (b): CT abdomen axial section showing the communication tract; (c) CT thoraco-abdominal sagittal section showing urinoma and the tract

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Figure 3: (a) CT thoraco-abdominal coronal section showing right sided pleural effusion; (b): CT abdomen axial section showing D-J stent in situ; (c) CXR showing resolution of pathology

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  Discussion Top

Urinothorax is an unusual cause of pleural effusion that is often overlooked.[3],[4] Fewer than 70 cases have been reported globally.[5] It most frequently develops secondary to obstructive uropathy blunt abdominal trauma or urinary tract surgery.[2],[6] Various etiologies of urinothorax have been observed as illustrated in earlier studies,[7] which could be broadly of two categories, i.e., obstructive or latrogenic/traumatic. Blockage or leakage to urine flow results in leakage of urine into the retroperitoneal space forming an urinoma. Urinoma can lead to pleural effusion. Mechanism of pleural fluid accumulation is unknown, but it is hypothesized that the retroperitoneal fluid drains along the pressure gradient into pleural space.[8] There are two theories concerning the mechanism for urinothorax, i.e. either the urine passes to pleural space through diaphragmatic lymphatic or, through defects in the diaphragm.[1]

In general, the patients with urinothorax have low pH, high LDH, resulting in misinterpretation of being an exudate. The average pleural fluid to serum creatinine ratio is in the range of 1.09–19.80.[2] Our patient presented with breathlessness and persistent dry cough 1 month after renal surgery (partial nephrectomy). The chest radiograph was suggestive of massive right-sided pleural effusion and thoracocentesis led to high suspicion of urinothorax due to distinctive smell and look of urine. The biochemical analysis was characteristic of exudate on the basis of light's criteria but transudate on the basis of protein gradient. The pleural fluid to serum creatinine ratio of more than one confirmed the diagnosis of urinothorax. Advanced imaging techniques, like renal scintigraphy with technetium-99m diethylene triamine pentaacetic acid, technetium-99m methylene dicysteine or with technetium-99m mercaptoacetyl triglycerine-3 can demonstrate any extravasation of urine from kidney or ureter.[2],[9] As our patient was a known CKD, and intravenous contrast was held not to be risk-free, a NCCT was done which showed the communication.

The possible causes of urinothorax in our case could be sloughing out of tissue from the repaired pelvicalyceal system and there might be temporary leakage of urine causing retroperitoneal urinoma leading to urinothorax subsequently in spite of functioning D-J stent. It is also possible that there may have been a temporary blockage of D-J stent by slough or clot which was cleared later on. When the urinothorax was drained by inter-costal tube the whole space collapsed and later on the defect in pelvicalyceal region was healed by fibrosis without further recollection of urine as the D-J stent was functioning. Therefore, this may be the possible cause for the spontaneous reversal of the process of urinary leakage to the pleural space. Increased awareness of this entity, high degree of clinical suspicion coupled with the availability of advanced imaging techniques and early intervention would result in early diagnosis and management of such extremely rare cases of urinothorax.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Bhattacharya A, Venkataramarao SH, Kumar S, Mittal BR. Urinothorax demonstrated on 99mTc ethylene dicysteine renal scintigraphy. Nephrol Dial Transplant 2007;22:1782-3.  Back to cited text no. 1
Garcia-Pachon E, Padilla-Navas I. Urinothorax: Case report and review of the literature with emphasis on biochemical diagnosis. Respiration 2004;71:533-6.  Back to cited text no. 2
Batura D, Haylock-Vize P, Naji Y, Tennant R, Fawcett K. Management of iatrogenic urinothorax following ultrasound guided percutaneous nephrostomy. J Radiol Case Rep 2014;8:34-40.  Back to cited text no. 3
Laskaridis L, Kampantais S, Toutziaris C, Chachopoulos B, Perdikis I, Tahmatzopoulos A, et al. Urinothorax-an underdiagnosed cause of acute dyspnea: Report of a bilateral and of an ipsilateral urinothorax case. Case Rep Emerg Med 2012;2012:395653.  Back to cited text no. 4
Kamble RT, Bhat SP, Joshi JM. Urinothorax: A case report. Indian J Chest Dis Allied Sci 2000;42:189-90.  Back to cited text no. 5
Dimitriadis G, Tahmatzopoulos A, Kampantais S, Ioannidis S, Radopoulos D, Katsikas V. Unilateral urinothorax can occur contralateral to the affected kidney. Scand J Urol 2013;47:242-3.  Back to cited text no. 6
Wei B, Takayama H, Bacchetta MD. Urinothorax: An uncommon cause of pleural effusion. Respir Med CME 2009;2:179-80.  Back to cited text no. 7
Broaddus VC, Light RW. Pleural Effusion. Mason RJ, Broaddus VC, Martin T, King Jr, TE, Schraufnagel D, Murray JF, Nadel, JA. editors. Murray and Nadel's Text Book of Respiratory Medicine 5th ed. Philadelphia: Saunders Elsevier Press: 2010. p. 1719-63.2.  Back to cited text no. 8
Jelic S, Sampogna RV. Detection of unrecognized urinothorax with renal scintigraphy. Kidney Int 2009;76:353.  Back to cited text no. 9


  [Figure 1], [Figure 2], [Figure 3]


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