Summary
Human cysticercosis is caused by the ingestion of eggs of the pork tapeworm (Taenia solium) (1). The ingested eggs evolve into onconspheres that cross the intestinal mucous membrane, distributing themselves to the muscles, making man their intermediate host (3).
The condition of rare systemic infestation is known as disseminated cysticercosis.
Introduction
Human cysticercosis is caused by the ingestion of eggs of the pork tapeworm (Taenia solium) [1], which lodged in the small intestine in its adult stage, releases gravid proglottids with eggs that will be eliminated with human feces (definitive host) [2].
The eggs of T. solium, which mature in oncospheres and metacestodes, are lodged in the soft tissues of pigs (natural intermediate host) to finally evolve into cysticerci [2], which cross the intestinal mucous membrane and are distributed to all the soft tissues of humans making it an intermediate host [3].
Diagnosis is made by observing the parasite by radiography, computerised tomography, magnetic resonance imaging, and biopsy [4].
The characteristic radiological sign is the “rice grain calcifications” corresponding to the calcifications formed by the inflammatory response and granulomatous tissue reaction due to the death of the cysticercus [5].
Clinically, calcifications are hard, painless nodules less than one centimeter in size, and represent dead parasites, so they do not require treatment. Disseminated cysticercosis (DCC) is a rare form of systemic presentation due to cysticerci infestation and there are few published reports [5].
Epidemiology
T. solium is endemic in regions of Latin America, India, China, Africa, and in other [6] regions with unsanitary conditions. In these sites, neurocysticercosis is the main cause of neuroparasitosis, and the main cause of acquired epilepsy in adults [7].
In Ecuador, heterogeneity has been demonstrated in the geographical distribution of cysticercosis, reporting active infections with prevalences that vary from 0.94% to 4.99% [8].
The importance of public health makes human cysticercosis a challenge in diagnostic and epidemiological terms.
Clinical case
An 84-year-old woman with chronic hip pain exacerbated when walking, radiating to the right thigh. She denies any prior history.
On physical examination, superficial nodules less than one centimeter were palpated, nonulcerated, hard, non-tender, on the hip, thighs, and forearms. Neurological examination was normal.
An anteroposterior X-ray of the pelvis was requested. This shows: osteoarthritis in the right hip (the cause of the pain) and multiple nodular or tapered lesions of hyperdensity, this lesions less than one centimeter in diameter immersed in the muscular tissue of the abdomen, pelvis and upper third of the legs.
When inquiring about risk factors for parasitosis, she referred to eating undercooked meat for a long period (in rural area of Ecuador) approximately 30 years ago (Figure 1).
Anteroposterior X-ray of the pelvis. White arrows indicate numerous calcified lesions, most of which are embedded in the muscles of the lower limbs and pelvis. The black arrow indicates joint space narrowing and osteoarthritis in the right hip.Black arrow indicates the decrease in joint space and osteoarthritis in the right hip. The black arrow points rather a subcortical degenerative cyst/erosion than the decrease of joint space in the right hip (sign of osteoarthritis). Source: Images are from the Center for Medical Specialties “Comitédel Pueblo”. Ecuadorian Institute of Social Security. I.E.S.S. Quito, Ecuador
Citation: Imaging 14, 2; 10.1556/1647.2022.00076
Anteroposterior X-ray of the pelvis. White arrows indicate numerous calcified lesions, most of which are embedded in the muscles of the lower limbs and pelvis. The black arrow indicates joint space narrowing and osteoarthritis in the right hip.Black arrow indicates the decrease in joint space and osteoarthritis in the right hip. The black arrow points rather a subcortical degenerative cyst/erosion than the decrease of joint space in the right hip (sign of osteoarthritis). Source: Images are from the Center for Medical Specialties “Comitédel Pueblo”. Ecuadorian Institute of Social Security. I.E.S.S. Quito, Ecuador
Citation: Imaging 14, 2; 10.1556/1647.2022.00076
Anteroposterior X-ray of the pelvis. White arrows indicate numerous calcified lesions, most of which are embedded in the muscles of the lower limbs and pelvis. The black arrow indicates joint space narrowing and osteoarthritis in the right hip.Black arrow indicates the decrease in joint space and osteoarthritis in the right hip. The black arrow points rather a subcortical degenerative cyst/erosion than the decrease of joint space in the right hip (sign of osteoarthritis). Source: Images are from the Center for Medical Specialties “Comitédel Pueblo”. Ecuadorian Institute of Social Security. I.E.S.S. Quito, Ecuador
Citation: Imaging 14, 2; 10.1556/1647.2022.00076
After this, additional radiographs of the chest, upper limb, and right knee were requested (Figure 2, Figure 3 and Figure 4).
Posteroanterior chest X-ray. White arrows indicate numerous calcified lesions, most of which are embedded in the muscles of the thorax. Source: Images are from the Center for Medical Specialties “Comité del Pueblo”. Ecuadorian Institute of Social Security. I.E.S.S. Quito, Ecuador
Citation: Imaging 14, 2; 10.1556/1647.2022.00076
Posteroanterior chest X-ray. White arrows indicate numerous calcified lesions, most of which are embedded in the muscles of the thorax. Source: Images are from the Center for Medical Specialties “Comité del Pueblo”. Ecuadorian Institute of Social Security. I.E.S.S. Quito, Ecuador
Citation: Imaging 14, 2; 10.1556/1647.2022.00076
Posteroanterior chest X-ray. White arrows indicate numerous calcified lesions, most of which are embedded in the muscles of the thorax. Source: Images are from the Center for Medical Specialties “Comité del Pueblo”. Ecuadorian Institute of Social Security. I.E.S.S. Quito, Ecuador
Citation: Imaging 14, 2; 10.1556/1647.2022.00076
Anteroposterior X-ray of the right elbow. White arrows indicate numerous calcified lesions, most of which are embedded in the muscles of the right arm and axillary region. Source: Images are from the Center for Medical Specialties “Comité del Pueblo”. Ecuadorian Institute of Social Security. I.E.S.S. Quito, Ecuador
Citation: Imaging 14, 2; 10.1556/1647.2022.00076
Anteroposterior X-ray of the right elbow. White arrows indicate numerous calcified lesions, most of which are embedded in the muscles of the right arm and axillary region. Source: Images are from the Center for Medical Specialties “Comité del Pueblo”. Ecuadorian Institute of Social Security. I.E.S.S. Quito, Ecuador
Citation: Imaging 14, 2; 10.1556/1647.2022.00076
Anteroposterior X-ray of the right elbow. White arrows indicate numerous calcified lesions, most of which are embedded in the muscles of the right arm and axillary region. Source: Images are from the Center for Medical Specialties “Comité del Pueblo”. Ecuadorian Institute of Social Security. I.E.S.S. Quito, Ecuador
Citation: Imaging 14, 2; 10.1556/1647.2022.00076
Lateral X-ray of the right knee. White arrows indicate numerous calcified lesions, most of which are embedded in the muscles of the right knee. Source: Images are from the Center for Medical Specialties “Comité del Pueblo”. Ecuadorian Institute of Social Security. I.E.S.S. Quito, Ecuador.
Citation: Imaging 14, 2; 10.1556/1647.2022.00076
Lateral X-ray of the right knee. White arrows indicate numerous calcified lesions, most of which are embedded in the muscles of the right knee. Source: Images are from the Center for Medical Specialties “Comité del Pueblo”. Ecuadorian Institute of Social Security. I.E.S.S. Quito, Ecuador.
Citation: Imaging 14, 2; 10.1556/1647.2022.00076
Lateral X-ray of the right knee. White arrows indicate numerous calcified lesions, most of which are embedded in the muscles of the right knee. Source: Images are from the Center for Medical Specialties “Comité del Pueblo”. Ecuadorian Institute of Social Security. I.E.S.S. Quito, Ecuador.
Citation: Imaging 14, 2; 10.1556/1647.2022.00076
The four images show abundant calcifications described as a radiological sign of “rice grain calcifications”, lesions compatible with DCC.
Discussion
This research contributes to the dissemination of a public health problem of social, economic and environmental relevance. Also promoting biosecurity actions to prevent this parasitosis.
The main limitation was access to additional imaging tests such as brain computed tomography, necessary studies to establish the diagnosis of neurocysticercosis.
Imaging methods stand out in the diagnosis of cysticercosis for being sensitive and non-invasive.
The treatment includes antiparasitics such as praziquantel and albendazole, symptomatic medication, or surgery. Albendazole has better cerebrospinal fluid penetration, its concentrations are not affected when administered with steroids, and it is less expensive [9].
Mention that in the patient's condition, the treatment will not eliminate the calcifications already established. The patient received symptomatic treatment and is under follow-up for trauma, due to hip osteoarthritis.
Ethical statement
The work respects all ethical principles and maintains the anonymity of patient data.
Conflicts of interest
The authors declare no conflicts of interest.
Funding
Fully financed by the authors.
Acknowledgments
We ackowledge the work of the radiographer Tnlgo. Nivel Lenin for taking the X-ray images.
References
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Cruz M, Davis A, Dixon H, Pawlowski ZS, Proano J: Operational studies on the control of Taenia solium taeniasis/cysticercosis in Ecuador. Bull World Health Organ 1989; 67(4): 401–407. pmid:2805217.
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