FIGURE 182.1. Eleven patients with abnormality extrinsic to the submandibular gland (SMG) presenting as masses of the submandibular space (SMS) and potentially of the SMG. All patients had contrast-enhanced computed tomography studies, except one in which a conventional sialogram was done. A, B: Patient 1. The mass, which on several images appeared to be possibly contiguous with the SMG, was shown to be extrinsic to the gland. This was most convincingly demonstrated on multiplanar images, which showed the facial vessels as seen in (B) (arrows) to be compressed between the reactive lymph node and the SMG. C: Patient 2 presented with a submandibular metastatic lymph node. The patient had not recalled having any skin cancer removed earlier in life. This node represented failure of that skin cancer in regional level 1 nodes. D–H: Patient 3. The image in (D) demonstrates a fluid density mass occupying the SMS mainly posterior to the floor of the mouth and displacing the SMG (arrow) posteriorly. There is a component of the fluid density within the sublingual space (arrowhead) that appears to be continuous with the main cystic collection over the back edge of the mylohyoid muscle. In (E), the axial section shows an additional area of possible connection with the floor of the mouth through an anatomic gap in the mylohyoid muscle (arrow) as it is in its more normal state on the opposite side transmitting a somewhat enlarged vein (arrowhead). In (F), the mass is mainly within the SMS, lying lateral to the mylohyoid and hyoglossus muscles (arrow). In (G), the ranula follows the neurovascular bundle through the mylohyoid muscle gap on the right (arrow) compared to its normal anatomic status on the left. In (H), the fluid clearly occupies the sublingual space as its site of origin (arrow) compared to the normal sublingual space on the right side. I: Patient 4, also with a ranula presenting as an SMS mass (arrow) with a small component in the floor of the mouth. The plunging ranula likely enters the SMS through the gap in the mylohyoid muscle anteriorly and inferiorly (arrowhead). (NOTE: These two cases of ranula show that the sublingual space and the fluid collection produced by a ranula may plunge into the SMS via either a gap in the mylohyoid muscle anteriorly or over the back edge of the mylohyoid muscle or both.) J: Patient 5 presenting with a SMS mass shown to be due to a lipoma composed of mature fat lying predominately laterally in the SMS. K: Patient 6 presenting with a left submandibular region mass that felt very firm, and there was concern about a primary SMG neoplasm. The study showed the mass to be due to a lipoma containing mature fat displacing the gland and compressing it somewhat, likely contributing to the clinical finding of a firm mass in that region. L: Patient 7 presenting with an SMS mass that was slightly tender. The mass was shown to be mainly fatty but containing other tissue. This was removed and turned out to be a lipoma with some elements of cellular degeneration but no evidence of liposarcoma. M: Patient 8 presenting with bilateral submandibular-region masses seen to be due to excessive accumulations of both encapsulated and unencapsulated fat. This mimicked bilateral SMG pathology and therefore had systemic pathology. This was shown to be due to lipomatosis and related lipomas. N: Patient 9. Before the advent of CT, conventional sialography was used to determine whether submandibular-region masses were intrinsic or extrinsic. This sialogram from the early 1980s shows an intrinsic mass (arrows) displacing the ducts within the SMG. Such studies are no longer done for this purpose. O: Patient 10 presenting with a rock hard mass in the angle of the mandible and submandibular region proven by CT to be due to a calcified lymph node. P, Q: Patient 11 presenting with a pulsatile mass in the SMS on this study shown to be due to a high-flow vascular malformation.

FIGURE 182.2. Two patients with potential manifestations of lymphoma. A, B: Contrast-enhanced computed tomography (CT) in Patient 1 presenting with a left submandibular region mass shown to be due to primary submandibular gland lymphoma. This was the only site of the patient’s disease and a highly unusual circumstance. C, D: Patient 2. Contrast-enhanced CT study done to evaluate palpable bilateral submandibular masses. These were due to lymphoepithelial cysts as seen in (D); the parotid glands were also involved. This was the initial presentation of this patient with human immunodeficiency virus infection.

FIGURE 182.3.  Three patients illustrating that benign and malignant disease within the submandibular gland (SMG) may have a relatively nonaggressive morphologic appearance. The studies also illustrate how tumors may be difficult to see within the SMG. A: Patient 1. Contrast-enhanced computed tomography (CT) shows a well-circumscribed, surgically proven benign mixed tumor. B, C: Patient 2. There is a well-circumscribed mass in the left SMG demonstrated in (B). In (C), a metastatic lymph node containing multiple metastases (arrows) indicates that this was a malignant lesion eventually proven to be an intermediate-grade mucoepidermoid carcinoma. D: Contrast-enhanced CT study in Patient 3 with a palpable right submandibular region mass. This well-circumscribed mass was shown to be a low-grade mucoepidermoid carcinoma. E: Patient 4 presented with a right submandibular region mass. Contrast-enhanced CT shows the mass to be intrinsic to the gland but not much different from normal glandular parenchyma. The image was optimized for contrast and level settings to demonstrate the lesion as it is seen. This was proven to be a benign mixed tumor at surgery.

FIGURE 182.4. A patient presenting with minimal tenderness in a mass in the left submandibular region. A: Ultrasound shows a lobulated mass within the submandibular gland (arrowheads) lying external to the mylohyoid muscle (arrow). Despite the lack of inflammatory findings, the CT with contrast in (B) shows the changes in the gland not to be due to a mass lesion but secondary to a stone impacted in the submandibular duct (arrow), with associated periductal inflammatory changes (arrowheads).

TABLE 182.1. SUBMANDIBULAR SPACE MASSES OF NONGLANDULAR ORIGIN

FIGURE 182.5. A patient presenting with tenderness and swelling in the right submandibular region. Both the pain and tenderness were progressive, and the mass was enlarging. A: Contrast-enhanced computed tomography study showing an aggressive mass replacing the submandibular gland with growth out of the capsule of the gland to invade the superficial musculoaponeurotic system along the expected course of the marginal mandibular division of the facial nerve (arrows) as well as thickening of the overlying skin and subcutaneous soft tissues. In addition, multiple lymph nodes are present that enhance abnormally (arrowheads). Some of these measure ,5 mm and contain obvious metastatic deposits (arrowheads). B: Gross spread along the mandibular division of the facial nerve is present within the parotid gland (arrows) as well as metastatic parotid lymph nodes (arrowheads). The metastatic nature of the nodes is mainly based on the avid enhancement as opposed to any focal nodal changes.