Globe calcification in congenital toxoplasmosis
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《美国医学杂志》
1 Department of Radiodiagnosis, Christian Medical College Hospital, Vellore Tamil Nadu, India
2 Department of Radiodiagnosis, Department of Neonatology, Christian Medical College Hospital, Vellore Tamil Nadu, India
Abstract
Various patterns of distribution of intracerebral calcification have been described in congenital toxoplasmosis. We report a case of congenital toxoplasmosis with a rare finding of calcification in the globe detected by CT scan that has not been described earlier.
Keywords: Globe calcification; Congenital toxoplasmosis; Retinochoroiditis
Congenital toxoplasmosis usually presents with a triad of chorioretinitis, cerebral calcification and convulsions. Retinochoroiditis is pathognomic of ocular toxoplasmosis, accounting for 95% of cases.[1] These patients may also present with retinal vasculitis, vitritis, anterior uveitis and scleritis.[2] Later, they may develop retinochoroidal scars.[3] We report a case of congenital toxoplasmosis with a rare finding of calcification in the globe detected by CT scan.
Case Report
A single live preterm boy baby born at 35 weeks' gestation was admitted to the nursery for respiratory distress. He was born to a primigravida by normal vaginal delivery with Apgar scores of 9 and 10 at 1 and 5 minutes, respectively. His birth weight was 2780 g, head circumference 32.5 cm and length 47 cm. On examination, the notable findings were tachypnoea and dry, erythematous skin. The liver was soft and palpable 5 cm below the right costal margin; a soft spleen was also palpable 4 cm below the left costal margin. Complete blood counts were normal except for thrombocytopenia (platelets 77,000/cumm). Serum electrolytes, calcium, phosphorus and blood sugar levels were in the normal range. The chest radiograph showed pneumonitis. On the second day, the baby was found to be jittery and had two episodes of convulsions. These features of a preterm baby raised the suspicion of congenital intrauterine infection and a detailed work-up was performed.
Radiograph of the skull anteroposterior view Figure1, showed multiple cortical calcifications and a calcific focus in the left orbit. Axial CT sections of the brain showed multiple foci of calcification bilaterally in cerebral cortex cerebellum and in the basal ganglia. In addition, nodular calcification at the posterior pole of the globe in the left orbit was present Figure2. Ophthalmological evaluation showed anterior uveitis, bilateral cataract and hemorrhages in the retina. Serology for Toxoplasma-specific IgM antibodies was positive both in the mother and infant, confirming the diagnosis of congenital toxoplasmosis. Serology for CMV, rubella and herpes simplex viruses 1 and 2 was negative.
Therapy for congenital toxoplasmosis was commenced with sulfadoxime, pyrimethamine and folinic acid. In addition, local and systemic steroid therapy was administered for ophthalmic involvement.
Discussion
Cerebral calcification is described in 65% of patients of congenital toxoplasmosis.[1] Usually the calcific foci are distributed diffusely in the cerebral parenchyma, predominantly in the cortex, basal ganglia or periventricular region. In a review of the English language press, nodular calcification at the posterior pole of the globe that was present in this case has not been reported.
The coats of the eye cannot be identified separately on CT scan: calcification in the wall of the posterior half of the globe could be scleral, choroidal or retinal in location. Intraretinal calcification classically occurs in retinoblastoma. It may also be seen in retinocytoma, tuberous sclerosis and epiretinal membranes.[4] Sclerochoroidal calcification could be dystrophic or metastatic in nature.[5] Dystrophic calcification is caused by secondary deposition of calcium in abnormal tissues despite normal serum levels of calcium and phosphate, whereas metastatic calcification results from deposition of calcium in normal tissues caused by abnormal calcium-phosphorus metabolism.[5] Metastatic calcification occurs in primary and secondary hyperparathyroidism, pseudohypoparathyroidism, sarcoidosis or in renal tubular alkalosis syndromes such as Bartter and Gitelman syndromes. [6],[7],[8] Rarely, sclerochoroidal calcification is idiopathic and seen in elderly white males.[9]
Chorioretinitis is the primary ocular pathology of congenital toxoplasmosis occurring in 95% of cases. Eye involvement is bilateral in 88% of patients[1]; however, in this case, calcification of the globe was unilateral. The hallmark of the disease is focal necrotizing retinochoroiditis that leads to a retinochoroidal atrophic scar.[3] Clinically established retinochoroidal scars have been identified at birth in some infants.[10] The diagnosis may be made by ophthalmic examination, fluorescein angiography, or ocular ultrasonography and confirmed on computed tomography.[6],[8],[9] In congenital toxoplasmosis, the calcification seen in the globe can be considered to be chorioretinal in location with involvement of sclera. The presumed mechanism would be dystrophic calcification at the site of chorioretinal and scleral inflammation.
Among children being evaluated for suspected congenital toxoplasmosis with neurological involvement, radiologists, pediatricians and ophthalmologists should be familiar with this rare finding of globe calcification.
References
1. Safadi MA, Berezin EN, Farhat CK, Carvalho ES. Clinical presentation and follow up of children with congenital toxoplasmosis in Brazil. Braz J Infect Dis 2003; 7 : 325-331.
2. Nussenblatt RB, Whitcup SM, Palestine AG. Ocular toxoplasmosis. In Uveitis: Fundamentals and the Clinical Practice. 2nd edn. St Louis; Mosby, 1996; 211-288.
3. Bosch-Driessen LE, Berendschot TT, Ongkosuwito JV, Rothova A. Ocular toxoplasmosis: clinical features and prognosis of 154 patients. Ophthalmology 2002; 109 : 869-878.
4. Miller DM, Benz MS, Murray TG, Dubovy SR. Intraretinal calcification and osseous metaplasia in Coats Disease. Arch Ophthalmol 2004; 122:1710-1712.
5. Boutboul S, Bourcier T, Heligon JP et al. Familial pseudotumoral sclerochoroidal calcification associated with chondrocalcinosis. Br J Ophthalmol 2004; 88:1094-1095.
6. Suzuki JI, Takeda M, Sekine N et al. Bilateral metastatic sclerochoroidal calcification in a patient with hyperparathyroidism. Ophthalmologica 1992; 205 : 10-14.
7. Bourcier T, Blain P, Massin P, Grunfeld JP, Gaudric A. Sclerochoroidal calcification associated with Gitelman syndrome. Am J Ophthalmol 1999; 128 : 767-768.
8. Vezzoli G, Soldati L, Jansen A et al. Choroidal calcifications in patients with Gitelman's syndrome. Am J Kidney Dis 2000; 6 : 855.
9. Schonherr U, Graupner M. Sclerochoroidal calcification-a rare disease pattern report on two patients, differential diagnosis and review of the literature. Klin Monatsbl Augenheilkd 2003; 220 : 39-43.
10. Mets MB, Holfels E, Boyer KM et al. Eye manifestations of congenital toxoplasmosis. Am J Ophthalmol 1996; 122 : 309-324.(Surendrababu NRS, Kuruvil)
2 Department of Radiodiagnosis, Department of Neonatology, Christian Medical College Hospital, Vellore Tamil Nadu, India
Abstract
Various patterns of distribution of intracerebral calcification have been described in congenital toxoplasmosis. We report a case of congenital toxoplasmosis with a rare finding of calcification in the globe detected by CT scan that has not been described earlier.
Keywords: Globe calcification; Congenital toxoplasmosis; Retinochoroiditis
Congenital toxoplasmosis usually presents with a triad of chorioretinitis, cerebral calcification and convulsions. Retinochoroiditis is pathognomic of ocular toxoplasmosis, accounting for 95% of cases.[1] These patients may also present with retinal vasculitis, vitritis, anterior uveitis and scleritis.[2] Later, they may develop retinochoroidal scars.[3] We report a case of congenital toxoplasmosis with a rare finding of calcification in the globe detected by CT scan.
Case Report
A single live preterm boy baby born at 35 weeks' gestation was admitted to the nursery for respiratory distress. He was born to a primigravida by normal vaginal delivery with Apgar scores of 9 and 10 at 1 and 5 minutes, respectively. His birth weight was 2780 g, head circumference 32.5 cm and length 47 cm. On examination, the notable findings were tachypnoea and dry, erythematous skin. The liver was soft and palpable 5 cm below the right costal margin; a soft spleen was also palpable 4 cm below the left costal margin. Complete blood counts were normal except for thrombocytopenia (platelets 77,000/cumm). Serum electrolytes, calcium, phosphorus and blood sugar levels were in the normal range. The chest radiograph showed pneumonitis. On the second day, the baby was found to be jittery and had two episodes of convulsions. These features of a preterm baby raised the suspicion of congenital intrauterine infection and a detailed work-up was performed.
Radiograph of the skull anteroposterior view Figure1, showed multiple cortical calcifications and a calcific focus in the left orbit. Axial CT sections of the brain showed multiple foci of calcification bilaterally in cerebral cortex cerebellum and in the basal ganglia. In addition, nodular calcification at the posterior pole of the globe in the left orbit was present Figure2. Ophthalmological evaluation showed anterior uveitis, bilateral cataract and hemorrhages in the retina. Serology for Toxoplasma-specific IgM antibodies was positive both in the mother and infant, confirming the diagnosis of congenital toxoplasmosis. Serology for CMV, rubella and herpes simplex viruses 1 and 2 was negative.
Therapy for congenital toxoplasmosis was commenced with sulfadoxime, pyrimethamine and folinic acid. In addition, local and systemic steroid therapy was administered for ophthalmic involvement.
Discussion
Cerebral calcification is described in 65% of patients of congenital toxoplasmosis.[1] Usually the calcific foci are distributed diffusely in the cerebral parenchyma, predominantly in the cortex, basal ganglia or periventricular region. In a review of the English language press, nodular calcification at the posterior pole of the globe that was present in this case has not been reported.
The coats of the eye cannot be identified separately on CT scan: calcification in the wall of the posterior half of the globe could be scleral, choroidal or retinal in location. Intraretinal calcification classically occurs in retinoblastoma. It may also be seen in retinocytoma, tuberous sclerosis and epiretinal membranes.[4] Sclerochoroidal calcification could be dystrophic or metastatic in nature.[5] Dystrophic calcification is caused by secondary deposition of calcium in abnormal tissues despite normal serum levels of calcium and phosphate, whereas metastatic calcification results from deposition of calcium in normal tissues caused by abnormal calcium-phosphorus metabolism.[5] Metastatic calcification occurs in primary and secondary hyperparathyroidism, pseudohypoparathyroidism, sarcoidosis or in renal tubular alkalosis syndromes such as Bartter and Gitelman syndromes. [6],[7],[8] Rarely, sclerochoroidal calcification is idiopathic and seen in elderly white males.[9]
Chorioretinitis is the primary ocular pathology of congenital toxoplasmosis occurring in 95% of cases. Eye involvement is bilateral in 88% of patients[1]; however, in this case, calcification of the globe was unilateral. The hallmark of the disease is focal necrotizing retinochoroiditis that leads to a retinochoroidal atrophic scar.[3] Clinically established retinochoroidal scars have been identified at birth in some infants.[10] The diagnosis may be made by ophthalmic examination, fluorescein angiography, or ocular ultrasonography and confirmed on computed tomography.[6],[8],[9] In congenital toxoplasmosis, the calcification seen in the globe can be considered to be chorioretinal in location with involvement of sclera. The presumed mechanism would be dystrophic calcification at the site of chorioretinal and scleral inflammation.
Among children being evaluated for suspected congenital toxoplasmosis with neurological involvement, radiologists, pediatricians and ophthalmologists should be familiar with this rare finding of globe calcification.
References
1. Safadi MA, Berezin EN, Farhat CK, Carvalho ES. Clinical presentation and follow up of children with congenital toxoplasmosis in Brazil. Braz J Infect Dis 2003; 7 : 325-331.
2. Nussenblatt RB, Whitcup SM, Palestine AG. Ocular toxoplasmosis. In Uveitis: Fundamentals and the Clinical Practice. 2nd edn. St Louis; Mosby, 1996; 211-288.
3. Bosch-Driessen LE, Berendschot TT, Ongkosuwito JV, Rothova A. Ocular toxoplasmosis: clinical features and prognosis of 154 patients. Ophthalmology 2002; 109 : 869-878.
4. Miller DM, Benz MS, Murray TG, Dubovy SR. Intraretinal calcification and osseous metaplasia in Coats Disease. Arch Ophthalmol 2004; 122:1710-1712.
5. Boutboul S, Bourcier T, Heligon JP et al. Familial pseudotumoral sclerochoroidal calcification associated with chondrocalcinosis. Br J Ophthalmol 2004; 88:1094-1095.
6. Suzuki JI, Takeda M, Sekine N et al. Bilateral metastatic sclerochoroidal calcification in a patient with hyperparathyroidism. Ophthalmologica 1992; 205 : 10-14.
7. Bourcier T, Blain P, Massin P, Grunfeld JP, Gaudric A. Sclerochoroidal calcification associated with Gitelman syndrome. Am J Ophthalmol 1999; 128 : 767-768.
8. Vezzoli G, Soldati L, Jansen A et al. Choroidal calcifications in patients with Gitelman's syndrome. Am J Kidney Dis 2000; 6 : 855.
9. Schonherr U, Graupner M. Sclerochoroidal calcification-a rare disease pattern report on two patients, differential diagnosis and review of the literature. Klin Monatsbl Augenheilkd 2003; 220 : 39-43.
10. Mets MB, Holfels E, Boyer KM et al. Eye manifestations of congenital toxoplasmosis. Am J Ophthalmol 1996; 122 : 309-324.(Surendrababu NRS, Kuruvil)