Radiographic Interpretation of Malignant Lesions (Part I) PDF

Radiographic Interpretation of Malignant lesions (Part I) 2024 - 2025 - 128 -  Radiographic Interpretation of Malignant lesions (Part I) Introduction Malignant tumors represent an uncontrolled growth of tissue. U...

Radiographic Interpretation of Malignant lesions (Part I) 2024 - 2025 - 128 -  Radiographic Interpretation of Malignant lesions (Part I) Introduction Malignant tumors represent an uncontrolled growth of tissue. Unlike benign neoplasms, they are more locally invasive, have a greater degree of cellular anaplasia, and have the ability to metastasize regionally to lymph nodes or distantly to other sites. Malignant tumors that arise de novo are termed primary tumors, and a lesion that originates from a distant primary tumor is termed a secondary or metastatic malignancy. Cancers may be caused by viruses, significant radiation exposure, genetic defects, or exposure to carcinogenic chemicals Common jaw malignancies have been divided into four categories: (1) Carcinomas (lesions of epithelial origin) (2) Metastatic lesions from distant sites (3) Sarcomas (lesions of mesenchymal origin) (4) Malignancies of the hematopoietic system. GENERAL CLINICAL FEATURES:  Pain or rapid swelling with no demonstrable dental cause.  Ulceration, presence of an indurated or rolled border may lead to underlying bone exposure.  Teeth may be displaced or loosened teeth over a short time.  Lymphadenopathy.  Foul smell. - 129 -  Radiographic Interpretation of Malignant lesions (Part I)  Weight loss, dysgeusia, dysphagia, dysphonia, hemorrhage.  Lack of normal healing after oral surgery. Age: Most oral cancers occur in men 50 years old and older; however, malignant tumors may occur at any age in either gender. GENERAL RADIOGRAPHIC FEATURES: Location:  Primary and metastatic malignant tumors may occur anywhere in the oral and maxillofacial region.  Primary carcinomas are more commonly seen in the tongue, floor of the mouth, tonsillar area, lip, soft palate, or gingiva and may invade the jaws from any of these sites.  Sarcomas are more common in the mandible and in posterior regions of both jaws.  Metastatic tumors are most common in the posterior mandible and maxilla. Some metastatic lesions grow at the apices of teeth or in the follicles of developing teeth Periphery and Shape: The periphery (border) of a malignant lesion is typically ill-defined border with lack of cortication and absence of encapsulation (a soft tissue or radiolucent periphery). This border usually extends from an area of bone destruction (radiolucent) to a region of normal bone with uneven extensions and is referred to as an infiltrating pattern. - 130 -  Radiographic Interpretation of Malignant lesions (Part I) This border is produced by finger-like extension of the tumor in many directions. However, some malignancies, especially squamous carcinomas arising in adjacent soft tissues and invading the mandible, may have well-defined borders (saucer shape or scoped appearance) The shape of a malignant tumor of the jaw is commonly irregular. Internal structure: The internal aspect is typically radiolucent in most instances (most malignancies do not produce bone and do not stimulate the formation of reactive bone). Occasionally, residual islands of bone are present, resulting in a pattern of patchy destruction with some scattered residual internal osseous structure. Some tumors, such as metastatic prostate or breast lesions, can induce bone formation, resulting in an abnormal-appearing internal sclerotic osseous architecture, whereas others, such as osteogenic sarcomas, can produce abnormal bone giving the involved bone a sclerotic (radiopaque) appearance. Effects on the surrounding structures: The effect on surrounding structures mirrors the destructive behavior of malignancies. Rapidly growing malignant lesions generally destroy supporting alveolar bone so that teeth may appear to be floating in space Internal trabecular bone is destroyed, as are cortical boundaries such as the sinus floor, inferior border of the mandible, follicular cortices of developing teeth, and cortex of the inferior alveolar neurovascular canal. - 131 -  Radiographic Interpretation of Malignant lesions (Part I) Because malignant tumors tend to grow rapidly, they invade via the easiest routes, such as through the maxillary antrum or through the periodontal ligament space around teeth, resulting in irregular widening with destruction of the lamina dura, they also may spread through the inferior alveolar neurovascular canal, causing widening with destruction of its cortical boundaries. Usually, no periosteal reaction occurs where the tumor has destroyed the outer cortex of bone; however, some tumors stimulate unusual periosteal new bone formation (see below diagram). Lesions such as osteosarcoma and metastatic prostate lesions as well as other tumors can stimulate the formation of thin straight spicules of bone, giving a “hair-on-end” or “sunburst” appearance. If there is a secondary inflammatory lesion coexisting with the malignancy, a periosteal reaction normally associated with an inflammatory lesion (e.g. onion skin–like) may be seen. Diagrammatic representation of radiologic features of oral malignancy. A, Ill-defined invasive borders followed by bone destruction. B, Destruction of the cortical boundary (floor of maxillary antrum) with an adjacent soft tissue mass (arrows). C, Tumor invasion along the periodontal membrane space causing irregular thickening of this space. D, Multifocal lesions located at root apices and in the papilla of a developing tooth destroying the crypt cortex and displacing the developing tooth in an occlusal direction (arrow). F, Bone destruction around existing teeth, producing an appearance of teeth floating in space. - 132 -  Radiographic Interpretation of Malignant lesions (Part I) Four types of effects on cortical bone and periosteal reaction, from left to right: (1) cortical bone destruction without periosteal reaction, (2) laminated periosteal reaction with destruction of the cortical bone and the new periosteal bone, (3) destruction of cortical bone with periosteal reaction at the periphery forming Codman’s triangles, and (4) a spiculated or sunray type of periosteal reaction. I. CARCINOMAS 1. Squamous Cell Carcinoma SCC in soft tissue (Epidermoid carcinoma). It is considered as the most common oral malignancy, may be defined as a malignant tumor originating from surface epithelium. Clinical Features: Most squamous cell carcinomas occur in persons older than 50 years. It appears initially as white or red (sometimes mixed), irregular patchy lesions of the affected epithelium. With time, these lesions exhibit central ulceration; a rolled or indurated border, which represents invasion of malignant cells; and palpable infiltration into adjacent muscle or bone. Pain may be variable, and regional lymphadenopathy with hard lymph nodes that may or may not be tethered to underlying structures may be present. Other clinical features include a soft tissue mass, paresthesia, anesthesia, dysesthesia, pain, foul smell, trismus, grossly loosened teeth, or hemorrhage. - 133 -  Radiographic Interpretation of Malignant lesions (Part I) Large lesions can obstruct the airway, the opening of the eustachian tube (leading to diminished hearing), or the nasopharynx. Patients often report significant weight loss and feel unwell. Radiographic Features: Location: Common in lateral border of the tongue, where bone invasion is observed in the posterior lingual aspect of the mandible. Lesions of the lip and floor of the mouth may similarly invade the anterior mandible. Lesions involving attached gingiva and underlying alveolar bone may mimic inflammatory disease, such as periodontal disease. This malignancy is also seen on the tonsils, soft palate, and buccal vestibule. Periphery and Shape: Polymorphous and irregular in shape due to underlying bone erosion. Invasion occurs in half of cases and is characterized most commonly by an ill-defined, non-corticated border. Other lesions have an ill-defined border with a wide transition zone with finger-like extensions into the surrounding bone Internal Structure: Totally radiolucent; the original osseous structure can be completely lost. Effects on Surrounding Structures: Evidence of invasion of bone around teeth may first appear as widening of the periodontal ligament space with loss (destruction) of adjacent lamina dura. Teeth - 134 -  Radiographic Interpretation of Malignant lesions (Part I) may appear to float in a mass of radiolucent soft tissue bereft of any bony support. Tumors may grow along the inferior neurovascular canal and through the mental foramen, resulting in an increase in the width and loss of the cortical boundary Destruction of adjacent normal cortical boundaries, such as the floor of the nose, maxillary sinus, or buccal or lingual mandibular plate, may occur. The inferior border of the mandible may be thinned or destroyed. If the tumor is extensive, pathologic fracture may occur. Differential Diagnosis: Squamous cell carcinoma is discernible from other malignancies by its clinical and histologic features. Occasionally, it is difficult to differentiate inflammatory lesions such as osteomyelitis from squamous cell carcinoma. However, Osteomyelitis usually produces some periosteal reaction, whereas squamous cell carcinoma does not. The bone loss from squamous cell carcinoma originating in the soft tissues of the alveolar process may appear very similar to periodontal disease, however the periodontal space widening in SCC is more irregular in shape, and characterized by band-like shape. SCC in different jaw locations - 135 -  Radiographic Interpretation of Malignant lesions (Part I) 2. Squamous Cell Carcinoma in Bone (primary intraosseous carcinoma): Primary intraosseous carcinoma is a squamous cell carcinoma arising within the jaw that has no original connection with the surface epithelium of the oral mucosa. Clinical Features: Gender: It is more common in males Age: It is more common in patient aged between 4th to 8th decades of life. Lesions may remain clinically silent until they have reached a fairly large size. The surface epithelium is invariably normal in appearance. Pain, pathologic fracture, and sensory nerve abnormalities such as lip paresthesia and lymphadenopathy may occur with this tumor. Radiographic Features: Location: more common in the mandible compared to the maxilla, with most cases being present in the molar region, in tooth bearing areas Periphery and Shape: ill-defined, although some have been described as well- defined. They are most often rounded or irregular in shape Internal Structure: Totally radiolucent with no evidence of bone production Effects on Surrounding Structure: These lesions are capable of causing destruction of the antral or nasal floors, loss of the cortical outline of the mandibular neurovascular canal, and loss of the lamina dura. Root resorption is - 136 -  Radiographic Interpretation of Malignant lesions (Part I) unusual. Teeth that lose both lamina dura and supporting bone appear to be floating in space. Differential Diagnosis If the border is obviously infiltrative with extensive bone destruction, a metastatic lesion must be excluded as well as multiple myeloma, fibrosarcoma, and carcinoma arising in a dental cyst. N.B: If the lesions are not aggressive and have a smooth border and radiolucent area, they may be mistaken for periapical cysts or granulomas 1ry intraosseous SCC - 137 -  Radiographic Interpretation of Malignant lesions (Part I) Note That: Squamous cell carcinoma may also originate in different locations (below table) SCC originating in Cyst SCC originating in maxillary sinus Clinical Features Dull pain of several months’ duration Initial signs may be very similar to May be associated with pathologic fracture inflammatory disease and may include and fistula recurrent sinusitis, nasal obstruction, epistaxis, sinus pain, and facial paresthesia Radiographic F. Anywhere an odontogenic cyst, most Maxillary Sinus Location commonly in the mandible posterior Shape Round or ovoid. Periphery Small lesions mostly well-defined and even corticated. Advanced lesions ill-defined with infiltrative margin Internal structure Radiolucent Radiolucent Effects Destroy LD, destruct the surrounding opacification of the maxillary sinus with cortices soft tissue and destruction of the surrounding osseous structures - 138 -  Radiographic Interpretation of Malignant lesions (Part I) 3. Central Mucoepidermoid Carcinoma: It is an epithelial tumor arising in bone, likely originating from pluripotential odontogenic epithelium or from a cyst lining. Clinical Features: It mimics a benign tumor or cyst with most common complaint is a painless swelling. Paresthesia of the inferior alveolar nerve and spreading of the lesion to regional lymph nodes Radiographic Features: Location: 3-4 times more common in the mandible compared to the maxilla, usually above the mandibular canal in premolar molar area. Periphery and Shape: unilocular or multilocular expansile mass The border is most often well-defined and well corticated and often crenated or undulating in nature, which is similar to benign odontogenic tumors. The peripheral cortication may be impressively thick, which belies its malignant nature. Rarely, the periphery is not corticated and has a more malignant appearance. Internal Structure: multilocular radiolucency having either a soap bubble or a honeycomb internal structure, which is displayed as round radiolucent areas with or without thick or sclerotic bony peripheries Effects on Surrounding Structures: expansion of adjacent cortical plates, often with perforation and sometimes extension into the surrounding soft tissues. - 139 -  Radiographic Interpretation of Malignant lesions (Part I) Similar to benign tumors, the mandibular canal may be depressed or pushed laterally or medially. Teeth remain largely unaffected by this disease, although adjacent lamina dura may be lost. There may be some regions of amorphous sclerotic bone on the lesion’s margins. Differential Diagnosis It may appear similar to a benign odontogenic tumor. Its malignant nature is revealed if there is expansion with perforation of the outer cortex with extension of the tumor into the surrounding soft tissues. The chief differential diagnosis is a recurrent ameloblastoma, Odontogenic myxoma and central giant cell granuloma also may be confused with mucoepidermoid tumor. Multilocular RL mucoepidermoid carcinoma with marginal sclerosis - 140 -  Radiographic Interpretation of Malignant lesions (Part I) 4. Malignant Ameloblastoma and Ameloblastic Carcinoma: Please Note the Following Malignant ameloblastoma is defined as an ameloblastoma with typical benign histologic features that is deemed malignant because of its biologic behavior (metastasis). Ameloblastic carcinoma is an ameloblastoma exhibiting the histologic criteria of a malignant neoplasm, such as increased and abnormal mitosis and hyperchromatic, large, pleomorphic nuclei. Clinical Features: Similar to benign ameloblastoma, appears in the jaw as a hard expansile mass with displaced and perhaps loosened teeth and normal overlying mucosa. Tenderness of the overlying soft tissue has been reported. Metastatic spread may be to the cervical lymph nodes; lung or other viscera; and the skeleton, especially the spine. - 141 -  Radiographic Interpretation of Malignant lesions (Part I) Radiographic Features: Location: more common in the mandible than in the maxilla, in premolar and molar region. Periphery and Shape: well-defined border occurs with cortication. However, malignant ameloblastoma may show some of the signs more commonly seen in malignant neoplasms—that is, loss of and subsequent breaching of the cortical boundary invading into the surrounding soft tissue. Internal Structure: commonly, multilocular, giving the appearance of a honeycomb or soap bubble pattern with robust and thick septa. Effects on Surrounding Structures: Teeth displacement and root resorption are common findings. The lesions may erode lamina dura and displace normal anatomic boundaries, such as the floor of the nose and maxillary sinus. The mandibular neurovascular canal may be displaced or eroded. Differential Diagnosis Benign ameloblastoma Odontogenic keratocyst Odontogenic myxoma Central mucoepidermoid tumor - 142 -  Radiographic Interpretation of Malignant lesions (Part I) 5. Metastatic Malignancy (2ry tumor) Metastatic lesions in the jaws usually arise from sites that are anatomically inferior to the clavicle. Jaw involvement accounts for less than 1% of metastatic malignancies found elsewhere. Most frequently the tumor is a type of carcinoma; the most common primary tumors are breast, lung, prostate, colon and rectum, kidney, thyroid, stomach, melanoma, testicle, bladder, ovarian, and cervical. Clinical features: Age: 5th to 7th decades Sex: Women have almost twice the number of metastatic tumors as men as breast metastases outnumber all other types. Patients may complain of dental pain, numbness or paresthesia of the third branch of the trigeminal nerve, pathologic fracture of the jaw, or hemorrhage from the tumor site. - 143 -  Radiographic Interpretation of Malignant lesions (Part I) Radiographic Features: Location: The posterior areas of the jaws, with the mandible more common than the maxilla. The maxillary sinus may be the next most common site, followed by the anterior hard palate and mandibular condyle. Frequently, metastatic lesions of the mandible are bilateral Also, lesions may be located in the periodontal ligament space (sometimes at the root apex), mimicking periapical and periodontal inflammatory disease, or in the papilla of a developing tooth. Periphery and Shape: may be moderately defined but have no cortication or encapsulation at their tumor margins; they also may have ill-defined invasive margins Both prostate and breast lesions may stimulate bone formation of the adjacent bone, which is sclerotic. Internal Structure: generally radiolucent. If sclerotic metastases are present (i.e., prostate and breast), the normally ragged radiolucent area may appear as an area of patchy sclerosis. Effects on Surrounding Structures: Typical of malignancy, the lesion effaces the lamina dura and can cause an irregular increase in the width of the periodontal ligament space. If the tumor has seeded in the papilla of a developing tooth, the cortices of the crypt may be totally or partially destroyed. Teeth may seem to be floating in a soft tissue mass and may be in an altered position because of loss of bony support - 144 -  Radiographic Interpretation of Malignant lesions (Part I) Some lesions may stimulate a periosteal reaction that usually takes the form of a spiculated pattern (prostate and neuroblastoma) The cortical bone of adjacent structures, such as the neurovascular canal, sinus, and nasal fossa, is destroyed. Differential Diagnosis If a known primary malignancy is present, the diagnosis of metastasis is straightforward. Multiple myeloma may be confused with metastatic tumors. Inflammatory lesions. A point of differentiation is that the periodontal ligament space widening from inflammation is at its greatest width and centered about the apex of the root. In contrast, the malignant tumor usually causes irregular widening, which may extend up the side of the root. - 145 - Radiographic Interpretation of Malignant Lesions (Part II) 2024 - 2025 - 146 -