Bone & Soft Tissue Pathology
Case 3 -
Soft Tissue Chondroma
Carrie Y. Inwards
Virtual Slides as well as Still Images are displayed below.
For the fastest viewing of virtual slides, click:
under each thumbnail image below. You must have Aperio ImageScope installed on your PC.
Or, click on slide thumbnail images to view each slide
If you do not already have Aperio ImageScope, Windows users with administrator privileges may download and install a free version in order to view USCAP Virtual Slides. Click the icon on the right to get your free copy: ||
in a Web-based slide viewer, which is somewhat slower.
If you have any difficulties viewing these slides, email or call George Clay at +1.724.449.1137.
A 35-year-old male presented with a mass involving his "distal ring finger" that had been there since
he was a teenager.
Case 3 - Slide 1
Case 3 - Figure 1 - Low power view of a cellular hyaline cartilaginous neoplasm with a nodular growth pattern. The nodules are closely associated with spicules of bone.
Case 3 - Figure 2 - The tumor nodules tend to pull away from the bone. Loose fibrous connective tissue also surrounds some of the bone.
Case 3 - Figure 3 - Low power view of a cellular hyaline cartilaginous neoplasm with a nodular growth pattern. The nodules are closely associated with spicules of bone.
Case 3 - Figure 4 - The tumor nodules tend to pull away from the bone. Loose fibrous connective tissue also surrounds some of the bone.
Case 3 - Figure 5 - Calcification diffusely involving some of the cartilage nodules.
Case 3 - Figure 6 - Some of the chondrocytes contain abundant eosinophilic cytoplasm.
Radiographs showed a nodular mass in the soft tissues adjacent to the base of the second proximal
phalanx with matrix mineralization. The mass was near the bone but the epicenter of the mass was in the
soft tissues with a concave deformity of the adjacent cortex, typical of a chronic extrinsic-type of
erosion secondary to an adjacent soft tissue mass. The imaging findings are consistent with a soft
tissue chondroma. A tiny metallic foreign body in the adjacent soft tissues was likely an incidental
The mass was submitted as multiple pieces of rubbery, gray-brown tissue aggregating 2.3 x 2.0 x 0.3
cm. Histologically, the tumor was composed of hyaline cartilage with a nodular growth pattern. It was
hypercellular and contained scattered areas of myxoid change within the stroma. The chodrocytes showed
mild to moderate cytologic atypia. Throughout the lesion nodules of tumor were closely associated with
thick, irregular trabeculae of bone. Dark blue granular calcification filled some of the cartilage
Soft tissue chondroma
Soft tissue chondroma is a rare benign cartilage lesion that has also been called extraskeletal
chondroma or chondroma of soft parts. It occurs most commonly in the soft tissues of the hands and
feet. The majority are located in the hands and wrists, especially in the fingers. The tumor is
typically associated with a tendon, tendon sheath or joint capsule. They can be seen in patients of any
age, but most are diagnosed in the fourth to sixth decades of life. Patients typically present with a
slowly growing and painless mass. They are solitary lesions and relatively small, rarely exceeding 3 cm
There is some overlap between the histologic features of chondrosarcoma and soft tissue chondroma of
the distal extremities. Therefore, one of the most helpful pieces of information the radiologist can
give a pathologist who is dealing with this differential is whether the lesion is arising primary in soft
tissue or bone. Radiographically, soft tissue chondroma is a well-demarcated extraskeletal tumor.
Occasionally it erodes the underlying bone giving rise to histologic and radiographic findings that may
be mistaken as features of malignancy. Radiographic evidence of calcification described as punctate,
ring-like, dystrophic, dense, or curvilinear has been reported in 30% – 70% of cases. MR signal
intensity can vary depending on the degree of calcification.
Most soft tissue chondromas contain variable amounts of mature hyaline cartilage with a lobular growth
pattern. They display increased cellularity and cytologic atypia when compared to benign intraosseous
cartilage tumors. The tumor cells oftentimes display a clustering pattern similar to synovial
chondromatosis. In addition, a variety of microscopic changes commonly occur in soft tissue chondroma
that can lead to confusion and misdiagnosis. These include myxoid degeneration, ossification, ischemic
necrosis, cystic change, a granuloma-like proliferation of epithelioid cells and multinucleated giant
cells around the periphery of cartilaginous nodules, and focal or diffuse calcification. The
calcification can be heavy and chunky or granular and lace-like. Chondroblastoma-like chondroma of soft
tissue is the term that has been used for soft tissue chondromas that contain hypercellular areas of
cells resembling the mononuclear cells of chondroblastoma.
Abnormalities of chromosomal region 12q14-15 and extra copies of chromosome 5 have been prominent in
the few cases that have been characterized cytogenetically. HMGA2 expression has also been documented in
a few cases of soft tissue chondroma.
Chondrosarcoma: Hypercellularity, cytologic atypia, and myxoid change are all histologic
features of both soft tissue chondroma and chondrosarcoma of bone. In addition, biopsies of soft tissue
chondroma containing areas of cortical erosion or metaplastic bone could be misinterpreted as
chondrosarcoma invading cortical bone. All of these features were seen in this case, emphasizing the
need for radiographic and clinical correlation. Histologic and/or radiographic evidence of destructive
permeation of bone are the most important criteria for diagnosing chondrosarcoma of the hands and feet.
Therefore, care should be taken when assessing a cartilage tumor for invasion. When soft tissue
chondromas erode cortical bone, nodules of the tumor are situated adjacent to the bone. This differs
from the destructive permeation of chondrosarcoma where fragments of pre-existing bone are totally
engulfed by tumor pouring through bone. It is also important to remember that among bone tumors of the
hands and feet, enchondroma is the most common tumor and chondrosarcoma is quite rare, representing less
than 10% in the Mayo files.
Bizarre parosteal osteochondromatous proliferation (Nora's lesion): The calcified cartilage of
Nora's lesion and soft tissue chondroma are histologically similar. However, in Nora's lesion the
cartilage matures into reactive new bone surrounded by a fibrovascular stroma. Radiographically, Nora's
lesion also differs from soft tissue chondroma since it shows a broad based attachment to the underlying
Periosteal chondroma: Radiographic information is probably the most helpful tool in separating
soft tissue chondroma composed entirely of cartilaginous nodules from periosteal chondroma.
Radiographically, periosteal chondroma typically is juxtacortical, attaches to the bone from beneath the
periosteum, and has saucer-like erosion.
Tenosynovial chondromatosis: Tenosynovial chondromatosis is an extraarticular counterpart of
synovial chondromatosis. Histologically, it shows the same features as soft tissue chondromas composed
predominately of mature hyaline cartilaginous nodules. However, grossly they differ since soft tissue
chondroma is a solitary lesion and tenosynovial chondromatosis is composed of multiple nodules.
Distinguishing the two lesions is important since tenosynovial chondromatosis reportedly has a higher
rate of local recurrence.
Tenosynovial giant cell tumors: Chondroblastoma-like soft tissue chondroma may be confused
with tenosynovial giant cell tumor due to a resemblance between the mononuclear cells of both lesions and
the presence of multinucleated giant cells. However, metaplastic cartilage is rarely seen in
tenosynovial giant cell tumor. Unlike most soft tissue chondromas, they usually contain scattered
lymphocytes and foamy histiocytes admixed with the mononuclear cells.
Synovial chondrosarcoma: Synovial chondrosarcoma is probably the rarest of chondrosarcomas.
Approximately 30 cases have been reported in the English literature. They usually occur with signs of
pre-existing or concurrent synovial chondromatosis. There is only one reported case of acral synovial
chondrosarcoma in the literature. It occurred de novo and involved the metacarpophalangeal joint of the
thumb in a 69-year-old male. Microscopically, synovial chondrosarcoma shows prominent nuclear atypia,
spindling at the periphery of chondroid lobues, necrosis, and myxoid change
Local excision is the treatment of choice for soft tissue chondromas. With complete removal of the
lesion, recurrence is rare.
This case emphasizes the importance of correlating the clinical, radiographic and histologic features
when dealing with cartilage tumors. Benign extraskeletal cartilage tumors and chondrosarcoma of bone
can have similar histologic features. In addition to soft tissue chondromas, synovial chondromatosis can
be mistaken for chondrosarcoma, particularly when it occurs at uncommon sites such as the vertebral
column and temporomandibular joint.
- Bertoni F, Unni KK, Beabout JW, Sim FH. Chondrosarcomas of the synovium. Cancer 67:155-162, 1991.
- Buddingh EP, Naumann S, Nelson M, Neff JR, Birch N, Bridge JA. Cytogenetic findings in benign cartilaginous neoplasms. Cancer Genet Cytogenet 2003;141:164-8.
- Cates JM, Rosenberg AE, O'Connell JX, Nielsen GP. Chondroblastoma-like chondroma of soft tissue. Underrecognized variant and its differential diagnosis. Surg Pathol 25(5):661-666, 2001.
- Cawte TG, SteinerGC, Beltran J, Dorfman HD. Chondrosarcoma of the short tubular bones of the hands and feet. Skel Radiol 27:625-632, 1998.
- Chung EB, Enzinger FM. Chondroma of soft parts. Cancer 41:1414-1424, 1978.
- Dahlen A, Mertens F, Rydholm A, Brosjo O, Wejde J, Mandahl N, Panagopoulos I. Fusion, disruption, and expression of HMGA2 in bone and soft tissue chondromas. Mod Pathol 2003;16(11):1132-1140
- Dahlin DC, Salvador AH. Cartilaginous tumors of the soft tissues of the hands and feet. Mayo Clin Proc 49:721-726, 1974.
- Fetsch JF, Vinh TN, Remotti F, Walker EA, Murphey MD, Sweet DE. Tenosynovial (extraarticular) chondromatosis. An analysis of 37 cases of an underrecognized clinicopathologic entity with a strong predilection for the hands and feet and a high local recurrence rate. Am J Surg Pathol 27(9):1260-1268, 2003.
- Fletcher CD, Krausz T. Cartilaginous tumours of soft tissue. Appl Pathol 6:208-220, 1988.
- Hondar Wu H-T, Chen W, Lee O, Chang C-Y. Imaging and pathological correlation of soft-tissue chondroma. A serial five-case study and literature review. Clinical Imaging 30(1):32-36, 2006.
- Humphreys S, Pambakian H, McKee PH. Soft tissue chondroma – a study of 15 tumours. Histopathology 10:147-159, 1986.
- Ogose A, Unni KK, Swee RG, May GK, Rowland CM, Sim FH. Chondrosarcoma of small bones of the hands and feet. Cancer 80(1):50-59, 1997.
- Wenger DE, Sundaram M, Unni KK, Janney CG, Merkel K. Acral synovial chondrosarcoma. Skel Radiol 31:125-129, 2002.
- Zlatkin MB, Lander PH, Begin LR, Hadjipavlou A. Soft tissue chondromas. AJR 144:1263-1267, 1985.