Ascaris lumbricoides is one of the most common helminthic infections of the intestinal tract in endemic areas [1].Ascariasis is an endemic disease in our country due to the prevailing poor sanitary conditions [2]. Physical migration of adult Ascaris is seen in sites such as biliary duct, liver parenchyma, pancreas, peritoneum, thoracic cavity, lacrimal duct, Eustachian tube, fallopian tube, brain, and even a pulmonary artery. Areas that are not commonly part of the Ascaris migration pattern are accessed through fistulization from sites that are normally infested with Ascaris [3].

We report a unique and extremely rare case of Ascaris lumbricoides extracted from Psoas abscess in an adult female.

Case Presentation

A 24-year-old female residing in a slum area was admitted to Urology department of a tertiary care hospital with complaints of abdominal pain in the right flank region, fever with chills and dysuria. Patient gave history of administering medication from a local medical practitioner one month back for abdominal pain and passage of worms in stool details of which were not known.

An Ultrasonography (USG) of abdomen and pelvis revealed mild ascites, mild worm infestation in the small bowel. Right kidney showed features suggestive of pyelonephritis with multiple renal abscesses. Worm in right Psoas muscle was also noted with resulting abscess formation in the upper and mid one third of psoas muscle. Left kidney was normal.

Computerised tomography (CT) abdomen and pelvis (plain and contrast) was performed in which right kidney showed suboptimal nephrogram which did not show excretion even after one hour delayed scan. Features suggestive of right pyelonephritis with multiple abscesses were noted. It also showed one of the abscess had ruptured and was traversing across posterior renal fascia and extending into posterior renal space, quadratus lumborum and psoas muscle. 

DTPA renogram study of the right kidney showed decreased perfusion and severely reduced cortical tracer uptake. Other parameter could not be commented upon due to severely reduced cortical function. DTPA renogram study of the left kidney was normal. Glomerular filtration rate was markedly reduced in the right kidney.

Routine blood analysis showed patient had hypochromic microcytic anaemia and leucocytosis. Stool for ova and parasites was negative for Ascaris eggs, larvae, or worms.

The patient was posted for right open nephrectomy. During the procedure, purulent discharge along with worm was seen after entering in the retroperitoneum. The worm was retrieved and sent to Department of Microbiology of the same hospital for identification where it was identified to be Ascaris lumbricoides based on its morphological features.

Figure 1: USG Abdomen Showing Worm in Psoas Abscess (Right Side) [Courtesy: Department of Radiology, LTMMC and GH].

Figure 2: Adult Ascaris lumbricoides Extracted from Psoas Abscess

The patient had an uneventful recovery thereafter.

Ascaris lumbricoides is the largest and most common intestinal nematode parasitising man. The only definitive host of Ascaris lumbricoides is man. The female can lay both fertilized and unfertilized eggs. The mature female worm can liberate about 2,00,000 eggs daily [4].

Prior studies have shown that Ascaris larva can mature into the adult worm form only in the gastro-intestinal (GI) system. Ascaris lumbricoides can be introduced into the urinary system either by fistula formation between the GI and urinary system or by retrograde migration of the adult worm through the urethra. Stressful conditions such as fever, illness, anaesthesia, or prior anthelmintic medications can precipitate urethral migration of the worm [3,5,6].

Bladder is the most commonly reported site of urinary ascariasis. Ascaris localizing to other parts of the urinary system is extremely rare. Quick et al. [7] reported a case of 39 year old male who expelled the worm form during urination. The patient had no symptoms other than tingling sensation in the penis and painless gross hematuria. Further investigation revealed that there was no connection between the gastrointestinal tract and the urinary system, but presence of a right renal stone was noted. Examinations for ova and parasites were negative for Ascaris [3,7]

Bustamante-Sarabia described a case of a 25 year old female who had history of three adult Ascaris worms being released from a subcutaneous abscess. A fistula that connected the transverse colon, proximal third of left ureter, and subcutaneous tissue was found during postmortem examination. Six live adult Ascaris forms occupying the renal pelvis and major calyces were also seen [3,7].

Taylor reported a case of a 6 year old boy who was hospitalized a few days after anti-helminthic treatment was started with symptoms of abdominal pain, cough, loss of appetite, fever. The patient also passed two adult Ascaris worms from the urethra. The right kidney was non-functional on isotope renal scan and it was then surgically removed. Ascaris lumbricoides ova in the kidney specimen were discovered on pathologic analysis [3,5].

Given the current data, we believe that our patient experienced retrograde migration of Ascaris through urethra as there was no sign of fistulization present radiologically and she gave history of consumption of medication for passage of worm in stool which is one of the factors favouring urethral migration of Ascaris lumbricoides. By this route the worm could have possibly reached the right kidney. As evidenced by CT abdomen and pelvis, one among the multiple renal abscesses present in right kidney had ruptured and was traversing across posterior renal fascia and extending into posterior renal space, quadratus lumborum and psoas muscle. It might be through this route that the worm gained access to the right Psoas muscle.

Ascaris infestation is a major health problem in endemic areas like India clinical presentation of which can be highly variable.

1. Heyman, H., et al. “Acute Urinary Retention as Presenting Symptom of Ascaris lumbricoides Infection in Children.”Pediatrics, vol. 71, no. 1, 1983, pp. 125–126.

2. Sundriyal, D., et al. “Biliary Ascariasis: Radiological Clue to Diagnosis.”Oxford Medical Case Reports, no. 3, 2015, pp. 246–247.

3. Baralo, B., et al. “Ascaris in the Urinary Tract: A Case Report and Review of the Literature.” Urology Case Reports, vol. 17, 2018, pp. 82–84.

4. Balasubramaniam, M., et al. “Ascaris lumbricoides in the Lacrimal Passage.” Indian Journal of Ophthalmology, vol. 48, no. 1, 1995, pp. 53–54.

5. Taylor, K.L. “Ascariasis of the Kidney.” Pediatric Pathology and Laboratory Medicine, vol. 15, 1995, pp. 609–615.

6. Bustemente-Sarabia, J., et al.“Ectopic Ascariasis.”American Journal of Tropical Medicine, vol. 26, 1957, pp. 568–569.

7. Quick, G., et al. “Urinary Ascariasis in a Man with Hematuria.” Southern Medical Journal, vol. 94, 2001, pp. 454–455