Calcifying fibrous tumor
Calcifying fibrous tumors, previously known as calcifying fibrous pseudotumors, are rare, benign fibroblastic tumors of the soft tissues.
It can occur at all ages and there is no strong gender predilection 1. Fewer than 200 cases have been reported in the English literature 1.
Most cases are asymptomatic, so the tumor is found incidentally on imaging 1. When symptoms are present, they are nonspecific and include palpable painless mass or localized pain 1.
Calcifying fibrous tumors can occur throughout the body's subcutaneous or deep soft tissues, with a few sites being more commonly reported 1:
- stomach (18%) 6
- pleura (10%)
- small intestine (9%) 5
- peritoneum (7%) 3
- neck (6%) 8
- mesentery (5%)
Many other sites have been described, including calcifying fibrous tumor of the lung, liver 2, and between muscles 8. Association with bone is unusual but a case involving the clivus has been reported 4.
The entity is included in the WHO classification of tumors of soft tissue under the fibroblastic/myofibroblastic tumors category.
It is a circumscribed, nonencapsulated mass and occasionally infiltrates surrounding tissues 1.
The lesion is composed predominantly of hyalinized stroma with interspersed psammomatous and dystrophic calcifications, fibroblastic spindle cells, and mononuclear/lymphoplasmacytic inflammatory infiltrate 1,3.
The appearance depends on the site but in general reflect the histology 1-7.
A mass is present with calcifications.
Partially calcified mass is demonstrated with some contrast enhancement, which progresses on delayed images.
The mass is hypoechoic with acoustic shadowing and foci of hyperechoic calcifications.
The mass has the following signal characteristics suggesting fibrosis/collagenous content:
- T1: slightly low signal intensity
- T2: low signal intensity
- T1 C+: relatively hypovascular but with slow progressive enhancement
Treatment and prognosis
Surgical excision is curative. The condition is benign, without reports of mortality; recurrence is rare 1.
The differential diagnosis is broad and depends on location but includes mesenchymal tumors such as 1:
- 1. Chorti A, Papavramidis TS, Michalopoulos A. Calcifying Fibrous Tumor: Review of 157 Patients Reported in International Literature. (2016) Medicine. 95 (20): e3690. doi:10.1097/MD.0000000000003690 - Pubmed
- 2. Jo BJ, Yoon SW, Ahn HJ, Kwon SW. Imaging findings of calcifying fibrous tumour of the liver. (2011) The British journal of radiology. 84 (998): e31-4. doi:10.1259/bjr/30585776 - Pubmed
- 3. Sudhakar S, Mistry Y, Dastidar A, Sen S, Gibikote S. Calcifying fibrous tumour: an unusual omental lesion. (2008) Pediatric radiology. 38 (11): 1246-8. doi:10.1007/s00247-008-0955-1 - Pubmed
- 4. Zhang T, Xu L, Gu L, Chen W, Pandey G, Wang J, Wu Y. Calcifying fibrous tumor of the clivus presenting in an adult. (2019) Radiology case reports. 14 (6): 771-774. doi:10.1016/j.radcr.2019.03.028 - Pubmed
- 5. Giardino AA, Ramaiya NH, Shinagare AB, Jagannathan JP, Stachler MD, Raut CP. Case report: Calcifying fibrous tumor presenting as an asymptomatic pelvic mass. (2011) The Indian journal of radiology & imaging. 21 (4): 306-8. doi:10.4103/0971-3026.90700 - Pubmed
- 6. Zhang X, Liu K, Li J. CT Features of Calcifying Fibrous Tumor of the Stomach. (2018) Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract. 22 (8): 1455-1456. doi:10.1007/s11605-018-3679-z - Pubmed
- 7. Liu Y, Lu Q, Wu XL, Shen GJ, Luo T. Ultrasonographic imaging of calcifying fibrous tumor of cervical esophagus: A case report. (2019) Medicine. 98 (28): e16425. doi:10.1097/MD.0000000000016425 - Pubmed
- 8. Hoffmann H, Beaver ME, Maillard AA. Calcifying fibrous pseudotumor of the neck. (2000) Archives of pathology & laboratory medicine. 124 (3): 435-7. doi:10.1043/0003-9985(2000)124<0435:CFPOTN>2.0.CO;2 - Pubmed