Indian Journal of Pathology and Microbiology

: 2018  |  Volume : 61  |  Issue : 4  |  Page : 640--642

Isolated spinal epidural hydatid disease: A diagnostic challenge in a needle core biopsy

Arpita Saha1, Kaushik Saha1, Vinita Agrawal2, Zafar Neyaz3, Awadesh Kumar Jaiswal4,  
1 Department of Histopathology, Health World Hospital, Durgapur, West Bengal, India
2 Department of Pathology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
3 Department of Radiodiagnosis, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
4 Department of Neurosurgery, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India

Correspondence Address:
Vinita Agrawal
Department of Pathology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow - 226 014, Uttar Pradesh

How to cite this article:
Saha A, Saha K, Agrawal V, Neyaz Z, Jaiswal AK. Isolated spinal epidural hydatid disease: A diagnostic challenge in a needle core biopsy.Indian J Pathol Microbiol 2018;61:640-642

How to cite this URL:
Saha A, Saha K, Agrawal V, Neyaz Z, Jaiswal AK. Isolated spinal epidural hydatid disease: A diagnostic challenge in a needle core biopsy. Indian J Pathol Microbiol [serial online] 2018 [cited 2023 Jan 27 ];61:640-642
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Full Text


Isolated primary spinal extradural hydatid cyst is very rare and is a diagnostic and therapeutic challenge.[1] We hereby share our experience of diagnosing the disease on computed tomography (CT)-guided linear tissue core in a patient having an epidural mass lesion, which was clinically and radiologically unsuspected.

A 22-year-old male patient presented to the neurosurgery department at our institute with complaints of backache for 8 months and with progressive weakness of both lower limbs for 6 months. It was associated with numbness below midtrunk with sphincter involvement for 3 months. There was no history of trauma, fever, or history of contact with tuberculosis patients. Neurological examination revealed spastic paraplegia with hypoesthesia below D4 level.

Magnetic resonance imaging (MRI) of the dorsolumbar spine showed mixed hypodense and hyperdense epidural soft tissue with few fluid intensities, along with cord compression and cord edema involving D2–D12. No intradural extension or vertebral changes were seen [Figure 1]. Ultrasonography of abdomen, chest X-ray, and cranial CT were unremarkable. His hematologic and biochemical parameters showed no abnormality. Tuberculosis was suspected, and a CT-guided biopsy was performed. It showed fibrocollagenous tissue and muscle bundles containing multiple palisaded nonnecrotizing granulomas comprising of plump histiocytes, lymphocytes, and foreign body-type giant cells. Foci of collections of foamy histiocytes and calcification were noted. Occasional fragmented small acellular eosinophilic membrane-like structures were noted within and around the foreign body-type giant cells. Ziehl–Neelsen stain for acid-fast bacilli was negative. No fungal element was seen. Periodic–acid Schiff (PAS) stain showed lamellations in the fuschinophilic membrane-like structures. Diagnosis of granulomatous inflammation associated with hydatid cyst-like membrane was suggested. Serology for Echinococcus infection was advised which was, however, negative.{Figure 1}

The patient was taken for operative management, and D1 to L1 laminectomy was done. Dirty granulation tissue was noted outside the dura with thick yellow pus inside. No membrane-like structure was identified. Dura was completely decompressed with due care to avoid spillage of content. The intraoperative squash smears were reported as inflammatory pathology.

The excision biopsy showed granulomas of similar morphology surrounding PAS-positive acellular-laminated membrane as in the previous biopsy [Figure 2].{Figure 2}

Postoperative period was uneventful with significant improvement in bilateral lower limb weakness and pain. The patient was discharged in satisfactory condition with instructions to continue antihelminthic treatment. The patient is in follow-up for 6 months with no recurrence of symptoms.

Hydatid (Greek for “watery cyst”) disease is a rare but important parasitic disease in endemic areas caused by the larval stage of the cestode Echinococcus granulosus.[2] Spinal hydatid accounts for <1% of all echinococcal lesions in the body. The ingested echinococcal egg hatches to embryo in intestine and penetrate the duodenal mucosa to reach the blood stream. Blood-borne echinococcal embryo usually spreads to the spine through vertebral venous plexuses and most commonly affects the thoracic (52%), followed by the lumbar (37%) and then the cervical and sacral spine.[3]

Braithwaite and Lees classified spinal hydatid disease into five types on the basis of its location into primary intramedullary, intradural extramedullary, extradural intraspinal, vertebral, and paravertebral.[4] Our patient presented with an extradural intraspinal lesion.

Presentation of the spinal hydatid ranges from initial asymptomatic stage to appearance of compressive myelopathic features including back pain (85%), radicular pain (25%–95%), and paraparesis (25%–77%).[3] Other uncommon features include secondary infections as in our case. Our patient presented with complete paraplegia which improved significantly following surgery.

Diagnosis of hydatid disease is done by radiology, serology, and histopathological confirmation. On MRI, the appearance of spinal hydatid cyst is quite characteristic with a sausage-shaped lesion with two domed ends, regular thin walls without septations or debris in the lumen. Signal intensity of the cyst content is similar to that of CSF.[5] However, in our case, the MRI findings of mixed hypodense and hyperdense epidural soft tissue mass lesion with few fluid intensities were observed which added to the diagnostic dilemma. Moreover, seronegativity of the patient and the absence of any membrane-like structure peroperatively was added to the diagnostic challenge. A high index of suspicion is warranted to make a preoperative diagnosis. This is important to prevent rupture and spillage of cyst content during surgery and for the addition of pharmacotherapeutic measures to prevent anaphylaxis and recurrence. Surgical excision is the mainstay of treatment, followed by antihelmintic drugs for 6 months to avoid recurrence. The disease usually has a poor clinical outcome with reports of relapse and progressive destruction of the vertebral column and neurological deterioration.[6]

The aim of this editorial is to highlight the importance of keeping the differential of hydatid disease in mind while evaluating cases of epidural mass even without characteristic radiological, serological, and operative findings. Even in tiny CT-guided biopsy specimen, the presence of ingested fragmented laminated membrane-like structure within the histiocytic giant cells should prompt the pathologist to suspect a diagnosis of spinal hydatid disease.

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.

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Conflicts of interest

There are no conflicts of interest.


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