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1. IMAGING OF TUMORAL CALCINOSISI. CHERIF, M. CHELLI BOUAZIZ, M. ATTIA, MF. LADEBDepartment of Radiology, Institut MT Kassabd’Orthopédie,Ksar Saïd, Tunisia. MK 22

2. INTRODUCTION • Idiopathic tumoral calcinosis is an unusual benign condition characterized by the presence of calcified soft tissue masses of varying size around the joints • The purpose of our study is to describe the imaging findings in idiopathic tumoral calcinosis with emphasis on MR imaging

3. PATIENTS AND METHODS • We retrospectively reviewed nine patients with histopathologically proven tumoralcalcinosis explored at two institutions over a ten-years period • Data relative to age, sex, location, clinical presentation, radiological features, histological findings and follow-up are reviewed

4. PATIENTS AND METHODS • All patients had radiographs and MR scans • Three patients underwent ultrasound studies • Computed tomography (CT) scans were performed in five patients • An additional Tc-99m labelled phosphate bone scintigraphy was performed in two patients

5. RESULTS • Patients were 6 males and 3 females • Age ranged from 2 to 53 years (mean 13 years) • Patients had no particular familial history nor biological abnormalities • A history of trauma was found in 2 cases • Clinical data are summarized in table 1

7. RADIOGRAPHS • Radiographs showed well-demarcated, lobulated and calcified juxta-articular soft tissue masses, unattached to bone in all cases • The masses consisted of conglomeration of multiple small and round opacities with different size and density separated by radiolucent septa • Fluid-calcium levels were observed in 2 cases (fig 1)

8. Fig. 1. — Anteroposterior radiograph of the left hip in a12- year-old boy shows well-demarcated lobulated calcified mass with fluid-calcium levels (arrow) also known as the “sedimentation sign” (case # 7)

9. RADIOGRAPHS • Radiographs also showed periosteal reaction associated with ill-defined patchy areas of bone condensation within the medullary cavity of the tibia in one patient • On scintigrams, increased radionuclide uptake was seen in the tibialdiaphysis • These lesions completely resolved on follow-up

10. ULTRASOUND (US) • US showed well-defined lobulatedsoft tissue masses demonstratingheterogeneousechogenicity • Cysts were separated by hyper-echoic thin septa, sometimes partially calcified • Colour Doppler detected blood flow within the septa in 2 cases • Fluid-calcium levels in two cases (fig 2) • Irregular and calcified areas in two cases

11. a b c Fig.2. — Same patient. Ultrasound study shows multi cystic mass(a). Cysts contain hypo-echoic liquid and are separated by hyper-echoic vascularized thin septa(b) Fluid-fluid levels are noted (c)

12. CT • One lesion showed a nodular calcified component separated by low-attenuation septa • Another lesion consisted of mainly large cystic components with low attenuation centres and thin calcified walls • Three lesions showed both patterns • Fluid-calcium levels were seen in 4 patients (fig 3) • Septal enhancement after contrast injection was seenin one case

13. Fig. 3. — Same patient. CT image of the left hip : the mass shows a mainly cystic component with low attenuation centres and thin calcified walls. Fluid-calcium levels are noted

14. MRI • On T1-weighted MR images, all lesions showed intermediate to low signal with more hypointense round or semi-lunar foci • On T2-weighted images, all lesions were heterogeneous and almost all presented mainly hyperintense multi loculated cystic structure associated to hypointense foci

15. MRI • Septa separating the cysts were thin, showing low signal on T1-weighted images and variable signal on T2-weighted images • Fluid-calcium levels were noticed in 5 cysts, upper layers being hyperintense and inferior ones hypointense • Peripheral and septal enhancements were noticed in all cases after Gadolinium administration.

16. MRI • Pseudo-tumoral areas were seen in 4 lesions showing • low signal intensity on T1-weighted images • heterogeneous and variable intensity on T2-weighted images • heterogeneous and marked enhancement after contrast injection. • These areas corresponded to mainly calcified zones on CT scans in 2 cases (figures4a,b,c&d) • No bone or joint involvement was seen on imaging

17. b c a Fig.4. — Same patient. Pseudo-tumoral area showing low signal intensity on T1-weighted MR images (a), heterogeneous variable intensity T2-weighted MR images (5) and fluid-calcium levels(c)

18. Fig.4d.— Gross examination of this area shows multiple small and empty cysts. We speculate that the particular pattern of collapsed cysts walls accounts for the pseudo-tumoral feature on MRI

19. Evolution • All patients underwent surgical resection • On gross pathological examinations, the masses were multiloculated and exuded yellowish creamy to chalky fluid • Microscopic analysis showed granulomas with calcified central area and separated by large fibrous walls

20. DISCUSSION • Idiopathic tumoral calcinosis is an unusual benign condition characterized by the presence of calcified soft tissue masses of varying size around the joints • Previously described by Giard in 1898, Duret in 1899 and Teutschländer in 1935 • The term “tumoral calcinosis” was used, and the first radiographs of the condition were published for the very first time by Inclan in 1943 (Figure 5) (1)

21. a b c Fig.5. : First published radiographs of tumoralcalcinosis lesions (a) Tumoralcalcinosis of the hip (b) Lateraland (c) anteroposteriorviews show tumoralcalcinosis of the elbow (Inclan A, Leon P, Camejo MG. Tumoral calcinosis.J Am Med Assoc 1943;121:490–495.)

22. DISCUSSION • Idiopathic tumoral calcinosis is a hereditary metabolic dysfunction of phosphate regulation associated with massive periarticular calcinosis. • Occurs in the first three decades of life • There is apparently no sex predominance (2) • Predilection for black people and people from tropical climates has been reported (3)

23. DISCUSSION • Slow growing soft tissue mass, painless in most cases, arising in the vicinity of large joints • Most common locations in descending order are the hip, elbow, shoulder, foot, and wrist (2) • In our series, the most affected site was the elbow (n = 9), with the hip coming in second position (n = 6) • Two thirds of patients have multiple lesions (4)

24. DISCUSSION • The tumor may : • interfere with joint motion, • cause pain by nerve compression, • Ulcerations and secondary infection occasionally appear • Laboratory analysis usually indicates : • Normal calcemia, parathyroid hormone level, renal function, alkaline phosphatase and uremia • Phosphatemia and Vitamin D levels are normal or slightly elevated

25. DISCUSSION • On radiographs typical appearance : Amorphous, cystic, and multilobulated calcification located in a periarticular distribution • CTbetter delineates the calcified mass • The cystic appearance shows fluid-calcium levels caused by calcium layering and commonly termed the sedimentation sign (5) • No adjacent bone erosion or destruction

26. DISCUSSION MR imaging : • T1-weighted sequences usually show inhomogeneous lesions with low signal intensity (6) • T2-weighted sequences generally shows inhomogeneous high signal intensity even though there is a large amount of calcification

27. DISCUSSION • The diagnosis of idiopathic tumoral calcinosis is one of exclusion • The differential diagnosis includes : chronic renal failure, primary hyperparathyroidism, calcinosis universalis, calcinosis circumscripta, chronic vitamin D intoxication, milk-alkali syndrome and collagen vascular diseases (6,7) • Such diseases are excluded by history and laboratory findings in our patients

28. DISCUSSION • These latter diseases are associated with a high serum calcium level while normocalcemia is seen in idiopathic tumoral calcinosis • Thediagnosis of tumoral calcinosis has to be refuted if an elevation of the blood levels of urea, calcium or non-protein nitrogen is found (7)

29. DISCUSSION • Complete surgical excision is the optimum treatment • In some patients, masses tend to recur easily despite repeated complete surgical resections • It is thought that recurrences are quite common in cases with hyperphosphatemiaor with predisposing geneticabnormality (8) • Management will be easier once all mechanisms of the disease are elucidated

30. CONCLUSION • Because many conditions mimic idiopathic tumoral calcinosis, diagnosis is difficult with diagnostic imaging alone • The radiologist plays a critical role in : • Avoiding unnecessary invasive procedures • Guiding the selection of appropriate biological tests • Making conclusive diagnosis of tumoral calcinosis

31. REFERENCES • Inclan A, Leon P, Camejo MG. Tumoral calcinosis. J Am Med Assoc 1943;121:490–495. • Aprin H, Sinha A. Tumoral calcinosis. Report of a case in a one-year-old child. Clin Orthop 1984 ; 185 : 83-86. • Barnacle AM, Gower PE, Mitchell AW. Ultrasonography of acute and chronic tumoral calcinosis. Clin Radiol 2002 ;57 : 146-149. • Fujii T, Matsui N, Yamamoto T, Yoshiya S, Kurosaka M. Solitary intra-articular tumoral calcinosis of the knee.Arthroscopy 2003 ; 19 : 1-4. • Hug I, Guncaga J. Tumoral calcinosis with sedimentation sign. Br J Radiol 1974;47:734–736. • Idiopathic tumoral calcinosis Skander CHAABANE, Mouna CHELLI-BOUAZIZ, Helmi JELASSI and al Acta Orthop. Belg., 2008, 74, 00-00 • Tumoral Calcinosis: Pearls, Polemics, and Alternative Possibilities Kathryn M. Olsen,Felix S. Chew, RadioGraphics 2006; 26:871–885. • Hammoud S, McCarthy EF, Weber K. Tumoral calcinosis in infants : A report of three cases and review of the literature. Clin Orthop 2005 ; 436 : 261-264.