Maxillary Sinus Osteosarcoma

Imaging Findings

As in several other expansile lesions of the sinonasal tract, many patients with a sarcoma may have undergone CT as the first imaging study. CT is particularly valuable in case of osteogenic sarcoma because it better defines the bony components of this malignant tumor (Lee et al. 1988). However, for most patients with soft tissue sarcomas, MR is the study of choice. It provides excellent definition of the relationship between tumor and neurovascular structures.

Imaging studies should be obtained before biopsy or exploration of the tumor, because surgery may blur the boundary between tumor and adjacent structures. When the internal carotid artery is thought to be at risk, MR angiography may help to detect arterial involvement. The diagnostic workup should include at least chest radiography, to rule out lung metastasis.

In most soft tissue sarcomas, cross sectional imaging findings are nonspecific and do not permit to distinguish among the different histotypes or even differentiate sarcomas from epithelial malignancies. However, in some lesions the presence of peculiar imaging features - combined with clinical and demographic findings - helps to suggest the proper diagnosis.

Unlike soft tissue sarcomas, the diagnosis of those arising from cartilage or bone may be easier due to specific imaging features related to the presence of cartilaginous or osteoid matrix, to peculiar intratu-moral calcifications, or to periosteal reaction.

On CT, most rhabdomyosarcomas appear as poorly defined, homogeneous (Hagiwara et al. 2001; Lee et al. 1996; Sohaib et al. 1998) or non homogeneous (Latack et al. 1987) solid masses, distorting soft tissues, destroying bone and extending into surrounding spaces. After contrast agent administration, enhancement is generally similar to adjacent muscles (Lee et al. 1996; Latack et al. 1987). Necrosis is an uncommon finding; hemorrhage or calcifications are generally not present (Lee et al. 1996; Hagiwara et al. 2001).

On T2 images, tumor signal is usually higher than muscles and fat (Yousem et al. 1990; Hagiwara et al. 2001), and very often heterogeneous (Ginsberg 1992) (Fig. 9.30). On T1, rhabdomyosarcomas appear isointense or slightly hyperintense than adjacent muscles. All tumors enhance. In some rhabdomyosarcoma multiple enhanced rings - resembling bunches of grapes - may be demonstrated. This has been described by Hagiwara et al. (2001) to be characteristic of botryoid embryonal rhabdomyosarcomas. This peculiar MR finding (botryoid sign) is probably related to the mucoid rich stroma covered by a thin layer of tumor cells (Hagiwara et al. 2001).

MR imaging seems to be better than CT for initial and follow up examination of rhabdomyosarcoma because of its multiplanar capability and ability to define the extent of lesion (Lee et al. 1996).

A part for the botryoid sign, several malignant tumors of the head and neck show similar finding. Lymphoma is different from rhabdomyosarcoma in its multifocal involvement and it is less often associated with invasion and destruction of adjacent bone. Liposarcomas usually have a component of fat density or intensity. Chordoma, chondrosarcoma, and osteosarcoma often have calcifications (Lee et al. 1996). Squamous cells carcinoma, which has imaging findings similar to rhabdomyosarcoma, mainly occurs in adults. Although rhabdomyosarcoma has a predilection for children less than 15 years, Nakhleh et al. (1991) reported a series of young adults (age ranging from 18 to 36 years) who had either embryonal or alveolar rhabdomyosarcoma of the head and neck. Therefore, the diagnosis of rhabdomyosarcoma should be considered in a young adult with an invasive soft tissue mass in the sinonasal tract.

Sinonasal tract chondrosarcomas may arise in tissues known to be formed of cartilage, as the nasal septum, or in bones that ossify in cartilage, as the sphenoid, the junction of the sphenoid with the perpendicular plate of the ethmoid, and with the vomer (Rassekh et al. 1996). A possible explanation for chondrosarcomas arising from sinuses that do not contain cartilage at any stage of their development, as the maxilla, is that the tumor arises from connective cells which possess the capacity to form chon-droblasts or osteoblasts (Jones 1973). It is interesting to observe that in the maxilla, chondrosarcoma more frequently develops in the walls, unlike the osteosar-coma that tends to arise from the alveolar ridge (Lee and van Tassel 1989).

Imaging findings distinctive of chondrosarcoma are optimally obtained by a combination of CT and MR (Lloyd et al. 1992). Owing to its slow-growing

Chondrosarcoma Maxilla

Fig. 9.30a-h. Rhabdomyosarcoma (embryonal type) arising from left fronto-ethmoidal sinuses in an adult male. a-c Coronal TSE T2 images show an homogeneous soft tissue mass with intermediate intensity, filling the left ethmoid sinus and extending, via the frontal recess, into the frontal sinus, partially surrounded by retained secretions (arrows on a). Due to its oblique course, the outline of fovea ethmoidalis appears less defined on b than on c, where tumor is clearly confined within the sinus without trespassing the roof (arrows on b and c). ^ ^ ^

Liposarcoma Tse

Fig. 9.30a-h. Rhabdomyosarcoma (embryonal type) arising from left fronto-ethmoidal sinuses in an adult male. a-c Coronal TSE T2 images show an homogeneous soft tissue mass with intermediate intensity, filling the left ethmoid sinus and extending, via the frontal recess, into the frontal sinus, partially surrounded by retained secretions (arrows on a). Due to its oblique course, the outline of fovea ethmoidalis appears less defined on b than on c, where tumor is clearly confined within the sinus without trespassing the roof (arrows on b and c). ^ ^ ^

nature and location in symptom-insensitive structures, sinonasal tract chondrosarcoma tends to present a considerable size at the time of diagnosis (Lee and van Tassel 1989). On CT, chondrosarcoma usually is shown as a lobulated soft tissue mass eroding the bone and extending into adjacent soft tissues. The transitional zone is sharp, without periosteal reaction (Lee and van Tassel 1989). Chondroid matrix within the tumor has a density lower than cancellous bone, although denser areas corresponding to local ized bone ossification can be present (Chen et al. 2002). When intratumoral calcifications are present, their nodular, plaque- or ring-like shape usually is a distinctive feature (Lee and van Tassel 1989; Lloyd et al. 1992; Rassekh et al. 1996) (Fig. 9.31).

At CT, the differential diagnosis is from other sinonasal tumors which present as a soft tissue mass with bone destruction and calcifications. Chondroma, os-teochondroma and osteoblastoma have high density internal areas, but these lesions tend not to invade a

Nasoethmoidal Recess

Fig. 9.31a-d. Chondrosarcoma of right naso-ethmoidal area. On coronal CT (a-b), the tumor both displaces (arrowhead on a) and invades adjacent structure (arrows). b Several small intratumoral densities, half-ring-like (arrowheads) can be recognized. On axial CT (c), invasion of maxillary sinus (white arrows), vertical lamella of the palatine bone (long black arrow), and pterygoid process (short black arrows) is shown. Intratumoral calcifications (arrowheads). d On T2 axial image, the chondrosarcoma has heterogeneous hyperintense signal with hypointense small areas corresponding to intratumoral calcifications (arrowheads)

Fig. 9.30a-h. (Continued) Tumor extends into the middle meatus and the ethmoidal infundibulum (black arrows on b) causing blockage of maxillary sinus, and invades its medial wall (arrowheads). On axial TSE T2 images (d-g) the portion of tumor within the left frontal sinus (T) is shown to abut the posterior wall (white arrows on e). The tumor invades also the posterior ethmoid cells causing blockage of the left sphenoid sinus (f). Anteriorly the lesion reaches the nasolacrimal duct (arrow on f). Invasion of middle meatus and maxillary sinus is seen on g (arrows). On sagittal enhanced T1 (h) the rhabdomyosarcoma (T) has mild, quite homogeneous enhancement. The extent within the frontal sinus is clearly defined as the signal of tumor differs from both fluid retention and mucosa thickening (short arrows). At the level of frontal sinus ostium, the lesion contacts a thick and prominent bony "beak" (arrowheads). A focal area of intracranial extent is demonstrated (long arrow)

b a d c the bone (Rassekh et al. 1996). Inverted papilloma can present with high densities in up to 50% of cases; more frequently multiple and discrete, in most cases they represent residual bone rather than calcifications (Som and Lidov 1994). Meningioma can have a similar appearance, but it tends to cause hyperostosis in the adjacent bone, rather than spotty calcifications. Osteosarcoma may resemble a chondrosarcoma with dense calcifications, but the calcifications are usually more diffuse and ill defined or linear with a "sunray" appearance (Lloyd et al. 1992).

The MR features of chondrosarcoma are more characteristic, they reflect the presence of an internal chondroid avascular matrix surrounded by a more vascularized peripheral growing tissue. On T2 weighted sequences, the chondroid matrix is hyper-intense because of high water content, while ossified or cartilage areas appear hypointense (Geirnaerdt et al. 1993). The administration of contrast agent results in enhancement of the vascularized peripheral rim and of several curvilinear septa that correspond to fibrovascular tissue components. A sharp demarcation between the enhancing rim or fibrovascular septa and the avascular chondroid matrix is usually observed. Other non-enhancing areas can be related to the presence of mucoid or necrosis.

Mesenchymal chondrosarcoma has a predilection for head and neck. In the sinonasal tract, skeletal le sions more commonly involve the maxilla. The presence of a bimorphic pattern on histology - a highly vascularized mesenchymal component surrounding cartilage islands - accounts for the relevant and inhomogeneous lobular enhancement on both CT and MR, mostly peripheral with a central low vascularized area. Arc- or ring-like, stippled and dense calcifications can be present (Shapeero et al. 1993; Chidambaram and Sanville 2000).

Most non radiation-induced osteosarcomas of the sinonasal tract arise from the inferior aspect of the maxilla (Lee et al. 1988), More rarely, other paranasal sinuses are the primary site (Park et al. 2004). An abnormal soft tissue mass with bone destruction is usually demonstrated by cross sectional imaging. Whereas CT is superior to MR in detecting tumor matrix mineralization - which occurs in up to 75% of the cases - and osteoid matrix calcification (Lee et al. 1988), MR is even more effective in demonstrating the intramedullary and extra osseous tumor components on both T1- and T2-weighted images (Boyko et al. 1987) (Fig. 9.32). When periosteal reaction is present, the typical sunburst appearance is better shown by thin-slice CT scans (Oot et al. 1986) (Fig. 9.33). Totally periosteal growth of a sphenoid sinus osteo-sarcoma with intracranial extent and absence of wall destruction has been recently described (Hayashi et al. 2000).

Osteosarcoma Maxillary

Fig- 9.32a-c. Osteosarcoma of left maxillary sinus. On axial CT (a), tumor presents as a soft tissue mass with large, irregular high densities at its posterior boundary corresponding to two nodules with different degree of tumor matrix mineralization (thick arrows). Medial maxillary wall is not recognizable. Erosion of nasolacrimal duct is shown (thin arrows). On unenhanced axial T1 image (b), a clear separation of tumor from intrasinusal hyperintense mucus is shown (black arrowheads). The medial maxillary sinus wall is displaced and distorted (short arrows). Invasion of nasolacrimal duct is present (black arrowheads). c After contrast agent administration, not only the intrasinusal portion enhances, but also the lesser mineralized nodule (asterisk). In addition, a soft tissue plaque-like enhancement is demonstrated surrounding the mineralized nodules (arrowheads)

Fig- 9.32a-c. Osteosarcoma of left maxillary sinus. On axial CT (a), tumor presents as a soft tissue mass with large, irregular high densities at its posterior boundary corresponding to two nodules with different degree of tumor matrix mineralization (thick arrows). Medial maxillary wall is not recognizable. Erosion of nasolacrimal duct is shown (thin arrows). On unenhanced axial T1 image (b), a clear separation of tumor from intrasinusal hyperintense mucus is shown (black arrowheads). The medial maxillary sinus wall is displaced and distorted (short arrows). Invasion of nasolacrimal duct is present (black arrowheads). c After contrast agent administration, not only the intrasinusal portion enhances, but also the lesser mineralized nodule (asterisk). In addition, a soft tissue plaque-like enhancement is demonstrated surrounding the mineralized nodules (arrowheads)

Sinus Osteosarcoma

Fig. 9.33a,b. Osteosarcoma of the right maxillary sinus. a CT shows that the tumor displaces the medial maxillary sinus wall with extensive periosteal reaction (thick arrows). Masticator space is invaded (thin arrows). Scattered intra-tumoral high densities are seen (arrowheads). b Enhanced T1 image demonstrates the submucosal spread of tumor (white arrowheads), invasion of the anterior (short arrows) and postero-lateral (black arrowheads) walls. Detailed map of masticator space spread is also shown (long arrows)

Fig. 9.33a,b. Osteosarcoma of the right maxillary sinus. a CT shows that the tumor displaces the medial maxillary sinus wall with extensive periosteal reaction (thick arrows). Masticator space is invaded (thin arrows). Scattered intra-tumoral high densities are seen (arrowheads). b Enhanced T1 image demonstrates the submucosal spread of tumor (white arrowheads), invasion of the anterior (short arrows) and postero-lateral (black arrowheads) walls. Detailed map of masticator space spread is also shown (long arrows)

Although most sinonasal tract leiomyosarcomas have been reported to arise from nasal cavity structures - such as the septum, the vestibule, the turbinates , and the choana - they can also origin from the paranasal sinuses and the hard palate (Tanaka et al. 1998; Sumida et al. 2001; Batra et al. 2001; Keck et al. 2001). Cross sectional imaging findings are nonspecific. In addition, the pattern of growth of the lesion may range from a non aggressive polypoid mass to a destructive lesion. On CT, leiomyosarcoma appears as a nonhomogeneous soft tissue bulky lesion (Batra et al. 2001), that remodels or invades the bone and shows slight to moderate enhancement. As in other locations in the body, the tumor is frequently associated with extensive necrotic or cystic changes and does not contain calcifications (Tanaka et al. 1998) (Fig. 9.34).

On MR, the tumor has been reported to present homogeneous intermediate signal on T1 weighted images and minimally inhomogeneous intermediate to slightly high signal on T2 weighted images compared to muscle. Moderate and inhomogeneous enhancement has been described (Tanaka et al. 1998) (Fig. 9.35).

Condrosarcoma Nasal

Fig. 9.34a-c. Leiomyosarcoma of right nasal fossa. a CT shows a soft tissue polypoid mass extending along lateral nasal wall and possibly invading the medial maxillary sinus wall (arrows). b-c Coronal CT images show remodeling (black arrows) and possible invasion of the medial maxillary sinus wall. (suggested by focal thickening on the sinusal surface of the wall) (white arrows)

Fig. 9.34a-c. Leiomyosarcoma of right nasal fossa. a CT shows a soft tissue polypoid mass extending along lateral nasal wall and possibly invading the medial maxillary sinus wall (arrows). b-c Coronal CT images show remodeling (black arrows) and possible invasion of the medial maxillary sinus wall. (suggested by focal thickening on the sinusal surface of the wall) (white arrows)

Jna Hard Palate

Fig. 9.35a,b. Leiomyosarcoma of hard palate with extensive erosion of bone on axial CT (a). The mass is characterized by upwards extent into the nasal cavity with submucosal spread into the nasal septum (thick white arrows), right medial maxillary sinus wall (arrowheads), and left maxillary sinus (black arrows). Bilateral involvement of hard palate by the hypointense tumor signal is seen (thin white arrows)

Fig. 9.35a,b. Leiomyosarcoma of hard palate with extensive erosion of bone on axial CT (a). The mass is characterized by upwards extent into the nasal cavity with submucosal spread into the nasal septum (thick white arrows), right medial maxillary sinus wall (arrowheads), and left maxillary sinus (black arrows). Bilateral involvement of hard palate by the hypointense tumor signal is seen (thin white arrows)

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Responses

  • jackie
    What is a lobulated soft tissue density in anterosuperior aspect of right nasal cavity?
    7 years ago

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