—  SPECIALTY CONFERENCE HANDOUT  —

Bone and Soft Tissue Pathology
Tuesday, March 9, 2004 - 7:30 pm
Ballroom B




Moderator:

ANTONIO NASCIMENTO
Mayo Clinic
Rochester, MN



Clinical histories are printed below.
Click on the case numbers for text and references of each case.
Click on each slide thumbnail image for an enlarged view

Case 1

DAVID R. LUCAS
University of Michigan
Ann Arbor, MI

Clinical Summary:

A 21-year-old man with hereditary multiple exostosis (HME) presented with new-onset pain and swelling in his left leg. Radiographs disclosed a large osteochondroma that formed a synostosis between the proximal fibula and tibia. The gross resection specimen contained a 10 cm ostechondroma with a lobulated cartilage cap, which varied from 0.2 to 2.0 cm in thickness. Destructive involvement of the stalk was not present, and there was no gross evidence of peripheral soft tissue invasion.



Case 1 - Figure 1 - Low-power photomicrograph depicting residual osteochondroma consisting of perichondrium on top, columns of chondrocytes reminiscent of the normal growth plate in the middle, and endochondral ossification at the base.

Case 1 - Figure 2 - Low-power view showing the lobular architecture of the cap consisting of lobules of cartilage separated by slit-like spaces as well as by thick fibrous bands at the bottom.


Case 1 - Figure 3 - Occasional cartilage lobules appeared to separate from the cap and invade beyond the perichondrium into skeletal muscle, as depicted in this low-power view.

Case 1 - Figure 4 - High-power photomicrograph illustratrating the bland cytological features of the tumor cells.

Case 1 - Figure 5




Case 2

GENE P. SIEGAL
University of Alabama
Birmingham, AL

Clinical Summary:

A 55 year old Caucasian woman presented with headache and neck pain of three months duration. She was otherwise in excellent health without known major illnesses or surgeries. A course of antibiotic therapy did not relieve her pain. A subsequent trial of steroids was similarly unsuccessful in alleviating her symptoms.

Three weeks prior to admission she developed blurred vision and "double vision" with drooping of her left eyelid. On physical examination she appeared healthy but with ptosis of her left eyelid with inhibition of both lateral and medial gaze. An MRI examination was performed which revealed a 4 cm mass replacing the sphenoid sinus and extending into the nasal pharynx while compressing and laterally displacing both internal carotid arteries. The upper tumor margin was seen to be at the level of the optic chiasm. On a T1 weighted image the signal intensity was isointense to muscle but heterogenous. The heterogeneity was slightly increased in its intensity on FLAIR and T2 weighted views.

Following intravenous contrast, the lesion demonstrated homogenous enhancement. Replacement of the cavernous sinuses was noted and the lesion was seen to be slightly larger on the left at the upper margin and eccentrically expanded to the right-inferiorly. The left wing of the sphenoid was enhanced as was the tuberculum sella. The brain parenchyma was viewed as normal throughout.

On maxillofacial CT of the sinuses diffuse changes were seen in the skull bones. A large soft tissue mass was again appreciated involving the sphenoid bone, including its body, greater and lesser wings, and pterygoids and the lesion was also seen to extend into the right nasal cavity. Marked hyperostosis of the posterior ethmoid sinus, mainly on the right, with a mass-effect on the posterior aspect of the nasal septum (causing deviation to the left) was further appreciated. Taken together the changes were thought to favor the diagnosis of a meningioma radiologically within the sphenoid sinus and pitutitary fossa.

Nasal endoscopy demonstrated a bulging of the posterior nasal cavity inferior to the sphenoid sinus and superior to the nasopharynx. This mass was smooth and mucosally covered with a thin shell of bone over the neoplasm. The tumor was white, and fleshy with minimal vascularity. Following endoscopic evaluation she underwent a biopsy of the mass.


Case 2 - Figure 1 - MRI following contrast demonstrating homogenous enhancement of a mass.

Case 2 - Figure 2 - Maxillofacial CT demonstrating marked changes in the bones surrounding the mass.


Case 2 - Figure 3 - Low power photomicrograph - note tumor osteoid admixed with highly vascular neoplastic spindle cell population & woven bone.

Case 2 - Figure 4 - Higher power photomicrograph - increased mitotic activity is seen.




Case 3

ANDREW HUVOS
Memorial Hospital for Cancer
New York, NY

Clinical Summary:

This is a destructive lytic intramedullary lesion of the right proximal femur in a 7 year old girl. Imaging workup showed a 9cm intramedullary metadiaphyseal tumor with cortical penetration and adjacent soft tissue extension. There were no skip lesions nor were any other bones affected. No pulmonary metastases were demonstrable.

An open biopsy was performed with appropriate immunohistochemical panel, electron microscopic analysis as well as RT-PCR study.


Case 3 - Figure 1 - Ewing's sarcoma. Clusters of small, round cells infiltrating bone. HE; 40x

Case 3 - Figure 2 - High-power views of Ewing's sarcoma. HE; 100x


Case 3 - Figure 3 - High-power views of Ewing's sarcoma. HE; 200x

Case 3 - Figure 4 - High-power views of Ewing's sarcoma. HE; 400x




Case 4

ANDREW G. ROSENBERG
Massachusetts General Hospital
Boston, MA

Clinical Summary:

A 64 year old woman presented to her physician complaining of a 1 year history of headaches and diplopia. The symptoms had become progressively more severe during this time period. Radiographic imaging studies revealed a focally calcified, well circumscribed mass in the region of the clivus that impinged upon the brain stem. A biopsy was performed.



Case 4 - Figure 1 - Lobular growth pattern of tumor.

Case 4 - Figure 2 - Periphery of lobules are hypercelluar.

Case 4 - Figure 3 - Myxoid component of tumor composed of bipolar and stellate cells arranged in interconnecting cords.


Case 4 - Figure 4 - Neoplastic cells in myxoid component have round to elongate nuclei with somewhat irregular contours. Small nucleoli are present in some nuclei.

Case 4 - Figure 5 - Chondroid areas composed of more homogenous solid appearing matrix with tumor cells located in lacunar spaces.


Case 4 - Figure 6 - Tumor cells stain strongly for S-100.

Case 4 - Figure 7 - Tumor cells are negative for keratin cocktail (AE1,3)




Case 5

K. KRISHNAN UNNI
Mayo Clinic
Rochester, MN

Clinical Summary:

22-year-old man presented with pain in the lower back and constipation. Roentgenograms revealed a mineralizing mass involving the coccyx.



Case 5 - Figure 1 - CT scan shows expansile lesion of coccyx with mineralization.

Case 5 - Figure 2 - MRI shows mass lesion expanding into soft tissue but still well demarcated.


Case 5 - Figure 3 - Bone-forming neoplasm juxtaposed to soft tissue. However, there is no permeation.

Case 5 - Figure 4 - Bony trabeculae lined with a single layer of osteoblasts. There is capillary proliferation between bony trabeculae.