A 61-year-old with a history of gout, atrial fibrillation, Raynaud phenomenon, hypertension, and congestive heart failure presented to the emergency department with a 2-week history of gradually worsening right upper-extremity weakness and paresthesias. Physical examination revealed mildly decreased sensation and strength, greater in the right arm than in the left. The patient’s initial laboratory values were calcium, 10.1 mg/dL (nl 9-10.5); creatinine, 1.1 mg/dL; phosphorus, 5.2 mg/dL (nl 3-4.5); alkaline phosphatase, 109 U/L (nl 36-92); and lactic acid, 3.1 mmol/L (nl 0.7-1.8).
Cervical spine MRI demonstrated anterolistheses from C2 to C5 with resultant multilevel, severe, central canal stenosis and corresponding T2 signal abnormality of the spinal cord. Numerous lobulated T1 and T2 hypointense foci extended from the craniocervical junction to the mid-cervical spine with involvement of the posterior elements (Figure 1).
Shortly afterward, the patient decompensated, with hypertension, bradycardia, and acute decline in motor strength in all four extremities. The patient was resuscitated and CT of the head and cervical spine were performed in preparation for emergent surgical decompression.
This demonstrated the lobulated structures seen on the prior MRI to be of homogeneous layering calcific density (Figure 2).
The patient underwent C1-C6 laminectomy, occipital-T3 posterior fusion and extensive debridement. Per the operative report, the cervical spine had erosive features and a calcified necrotic process identified in pockets of soft tissue throughout the neck. Multi-level lateral masses were eroded. The C1-C2 joint space was filled with pockets of “cheese-like” calcific material.
Pathology demonstrated extensive amorphous and granular appearing calcifications in the soft tissue. The smear preparations showed tiny, mixed amorphous calcium crystals, which aggregated into groups and lacked the typical needle or rhomboid shapes of monosodium urate (gout) or calcium pyrophosphate (pseudogout) crystals.
The fixed tissue sections displayed multiple lobules of granular calcifications within the soft tissue, separated by fibrous septa. Rare areas had more active lesions containing macrophages, occasional osteoclast-like multinucleated giant cells, and mild chronic inflammation at the periphery of the lobules. However, most appeared inactive, with only central small, granular and larger, dense psammomatous-like calcifications within fibrous septa (Figure 3).
Tumoral calcinosis. Differential diagnoses include calcific tendinosis, calcium pyrophosphate dihydrate crystal deposition disease (CPPD), tophaceous gout, calcific myonecrosis, myositis ossificans and synovial osteochondromatosis.
Tumoral calcinosis (TC) is characterized by lobular, densely calcified, mass-like lesions classically confined to the soft tissues, generally at the extensor surface of a joint.1 Reports of TC can be traced back to 1898; however, it was first described in the American literature in 1943 by Inclan et al.2
Tumoral calcinosis may be genetic, the result of prior traumatic injury, or the result of a metabolic derangement, most commonly chronic renal failure, which accounts for approximately 23% of cases.3 Onset is typically in the second decade of life, with a reported increased frequency in African Americans.4 The condition can be divided into primary and secondary varieties, and there are two primary subtypes: hyper-phosphatemic TC secondary to a gene mutation in GaINAc or FGF23, and normo-phosphatemic TC secondary to a gene mutation in the SAMD9 gene.5 The secondary type results from chronic renal failure.
Tumoral calcinosis of the spine is rare, with only 30 cases reported in the literature, most involving the cervical (48%) and lumbar (45%) spine. Only two reported cases involve the thoracic spine.6 In descending order of prevalence, TC most commonly involves the hip, elbow, shoulder, foot, and wrist joints.2
Owing to the characteristic soft-tissue calcifications of tumoral calcinosis, CT plays a primary role in diagnosis. In cases of advanced disease, the condition may be identified on radiographs. MRI is often performed after CT to evaluate for spinal cord signal abnormalities and for presurgical planning.
The characteristic CT imaging appearance of TC is multilobulated cystic or amorphous periarticular calcifications. Erosive changes of adjacent osseous structures are common. Homogeneous or layering density can also be seen on CT. These lesions typically demonstrate T1 hypointense signal on MRI. There is variable T2 signal, which may be hypo- or hyperintense despite the high amount of calcium.1
Imaging appearance, anatomic distribution, clinical history, and laboratory values are helpful in differentiating these processes. Treatment is individualized after the condition is subtyped into one of the above etiologies. The choice between medical and surgical therapy depends on multiple variables, including subtype, location, and severity.
The cervical spine is an uncharacteristic anatomic location for tumoral calcinosis. However, this case illustrates TC’s potentially devastating effects on the spinal cord, as well as the importance of including TC in the differential diagnosis of soft-tissue, periarticular calcific process in the cervical spine.
Christiansen EM, Mallon S, Felicella MM, Pitt A, Hughes J. Tumoral Calcinosis. Appl Radiol. 2021;50(3):53-55.
Affiliations: St. Joseph’s Hospital, Phoenix, AZ (Dr Christiansen); Barrow Neurological Institute, Phoenix, AZ (Drs Mallon, Felicella, Pitt, Hughes).