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Tumor Board Conference from the University of Pittsburgh

Tumor Board Conference from the University of Pittsburgh

The patient is a 64-year-old woman with a nonhealing oral ulcer.

Karen T. Pitman, MD: We will be discussing the case of a 64-year-old
woman who was referred to the Department of Otolaryngology, University
of Pittsburgh Medical Center, with the chief complaint of a nonhealing
ulcer in the oral cavity that had been present for 2 months. Upon further
questioning, the patient noted the recent onset of right otalgia and a
10-pound weight loss. She denied experiencing trismus or odynophagia.

The patient's social history was remarkable for alcohol and tobacco
abuse. Her past medical and surgical history was remarkable only for periodontal
disease and the subsequent loss of all dentition 10 years ago. An otolaryngologist
in the community had seen her 2 weeks prior to referral, and a biopsy of
the oral ulcer disclosed squamous cell carcinoma.

On physical examination, the patient appeared to be adequately nourished
and to be her stated age. Inspection of the oral cavity revealed that the
patient was edentulous and had an ulcerative lesion of the right retromolar
trigone, which extended into the soft palate, buccal mucosa, and base of
the tongue. Leukoplakia was noted along the floor of the mouth and the
right ventral surface of the tongue. Figure
1
depicts the location of the lesion, which had its epicenter on the
alveolar process of the ascending ramus of the mandible.

Flexible fiberoptic examination of the nasopharynx, hypopharynx, and
larynx was normal. There was no palpable cervical adenopathy.

Our pathologists reviewed the biopsy specimens obtained at the outside
institution and confirmed the diagnosis of moderately differentiated squamous
cell carcinoma.

Determining
the Extent of the Primary Lesion

Dr. Pitman: What specific concerns would you have about the extent
of the primary lesion?

Carl H. Snyderman, MD: Tumors in the retromolar trigone typically
present at an advanced stage. Tumors in this area raise several concerns.
First, the close proximity of the retromolar trigone to the mandible poses
a high risk of invasion of the mandible, either by direct invasion through
the alveolar surface or along the inferior alveolar nerve. Another concern
is the deep infiltration into the pterygoid musculature, making it more
difficult to obtain clear surgical margins. With involvement of the tongue
base and soft palate, there is downgrading of oral function following surgery,
which should be considered the therapy of choice. There is also the risk
of a second primary tumor.

Dr. Pitman: How do you clinically assess the patient for bone
invasion?

Dr. Snyderman: One historical clue is the presence of hypesthesia
or paresthesia of the inferior alveolar nerve. In my experience, however,
I have found these symptoms to be rare, and I tend to rely on radiographs
to determine bony invasion. In the edentulous patient, there may be irregularities
on the mandibular surface due to prior dental extractions, which can mimic
erosion by cancer. I usually start with a CT scan to evaluate the mandible
for cortical erosion. If perineural infiltration is a concern, MRI is probably
a better imaging study to look for extension of the tumor along the marrow
space.

Dr. Pitman: Both CT and MRI were obtained before the patient
was referred to our institution. Dr. Weissman, from a practical standpoint,
when one encounters a patient with a tumor approximating bone who has not
undergone imaging studies, what is your recommendation about the sequence
of imaging studies to obtain?

Jane L. Weissman, MD: The questions you ask will determine which
studies you recommend. If you want to determine whether the mandible exhibits
cortical erosion, a CT scan is the study of choice. Ideally, images should
be obtained perpendicular to the tumor mass so that you could optimally
look for enhancement along the course of the nerve within the bone. The
inferior alveolar nerve will enhance long before the CT scan shows erosion
or enlargement of the osseous canal.

Radiographic Findings

Dr. Pitman: Dr. Weissman will now review the radiographic studies
obtained for this patient.

Dr. Weissman: A contrast-enhanced CT scan demonstrated the extensions
of the soft-tissue mass (Figure 2). On
the side of the tumor, the fat is effaced, and the tumor is inseparable
from the ascending ramus of the mandible and from the posterior aspect
of the maxilla. The tumor is also inseparable from the pterygoid muscles.
The tumor extends into the lateral aspect of the soft palate and uvula.
At the base of the tonsillar pillar, there is a suggestion that the tumor
is extending submucosally around the glossopharyngeal sulcus and into the
base of the tongue.

It is difficult to assess bone involvement from this study. Gross involvement
would be apparent; you would see frank erosion of the mandible. Gross perineural
involvement might be apparent with replacement of the normal marrow.

The axial T1-weighted MR images before contrast demonstrate that the
tumor does abut the signal void of the cortex of the ascending ramus; this
is seen better after gadolinium enhancement and with fat suppression (Figure
3
). The MRI shows that the tumor is inseparable from the mandible,
but the subtle irregularity of the cortex is imperceptible. You can see
the tumor infiltrating into the confluent pillar, again probably submucosally,
and extending downward.

The images of the neck show some suspicious lymph nodes. By size criteria,
these nodes are normal, but the inhomogeneous enhancement suggests the
possibility of tumor involvement.

In summary, the radiographic studies reveal a tumor in the retromolar
trigone, extending to the lateral aspect of the soft palate and along the
glossopharyngeal sulcus to the tongue base. There is no other tumor involvement
of the mandible, but subtle cortical erosion cannot be assessed by these
studies. Examination of the neck shows a suspicious mass in the right neck
(level II), and the left neck looks normal.

What Further Studies Are Needed?

Dr. Pitman: Are there any other studies that could be obtained
to help assess for mandibular invasion?

Dr. Weissman: A software package for the CT scanner called the
DentaScan is used in our institution to evaluate the thickness of the alveolus
in edentulous patients in whom the dentist is planning to do dental implants.
What makes it useful for the dentist and for our purposes is that this
program allows you to obtain extremely thin slices through the alveolar
process. Typically, 1.0-mm intervals are utilized, and they are scanned
without an interslice gap. This is usually done without contrast for the
purpose of looking for obvious bony involvement, rather than the extent
of the soft-tissue component of the tumor.

The DentaScan software reformats direct coronal and axial images. I
think that perhaps the axial images and the 1.0-mm thin slices are the
most helpful part of this study for evaluating both the maxillary buttress
and the ascending ramus of the mandible.

Jonas T. Johnson, MD: I would argue that further imaging of this
patient is unnecessary, because it is inconceivable that you would surgically
manage a T3 lesion of the retromolar trigone without a segmental mandibulectomy.
The only exception would be if you were considering the possibility of
irradiating the patient, in which case, further imaging might be needed
to convince yourself that irradiation would be a bad choice. The retromolar
trigone comprises the soft tissue overlying the mandible, and less than
a segmented resection would be an inadequate oncologic operation. Conceptually,
what you need to ask yourself is how extensive a resection is needed. In
this case, I think a segmental mandibulectomy is a foregone conclusion.

Dr. Pitman: Before proceeding with the formulation of the treatment
plan for this lesion, the presence of a second primary carcinoma or distant
metastasis must be ruled out. What further studies should be obtained for
this purpose?

Jennifer R. Grandis, MD: The lung and esophagus are among the
most common sites of second primary tumors in patients with upper aerodigestive
tract squamous cell carcinoma. These tumors would be discovered by radiographic
studies, such as a barium swallow and chest radiograph. Examination under
anesthesia and direct laryngoscopy are also performed. I do not routinely
do bronchoscopy to rule out endobronchial primaries. Distant metastases
are relatively uncommon, and the most likely location is the chest.

Dr. Pitman: Do you think that flexible fiberoptic laryngoscopy
performed in the office is satisfactory for an endoscopic examination,
or do you need to repeat the examination in the operating room?

David E. Eibling, MD: The answer to that question, I think, depends
on the patient. I occasionally perform flexible fiberoptic laryngoscopy
in the office. However, I routinely repeat it in the operating room, although
the question of whether this is necessary is valid. In some cases, you
really are less able to examine certain areas, such as the post-cricoid
area and pyriform sinus, in the office; these are best seen in the operating
room.

Dr. Johnson: I would still repeat laryngoscopy, in part, because
I agree that you probably see some areas, such as the pyriform sinus, better
directly than indirectly. I also do esophagoscopy in the operating room.
Since I am doing endoscopy, it seems appropriate to look both places, but
I have wondered if that is necessary because we have already done flexible
endoscopy in the office and billed for it.

Eugene N. Myers, MD: I think that the two examinations are complementary,
and I do not exclude either one. The only way to evaluate vocal cord movement
is in the office when the patient is awake. Often, because of a tumor that
is either bulky or exophytic and hangs over the glottis or into the pyriform
sinus where there is a lot of edema, you really do not obtain an accurate
view of the extent of the tumor on an office examination.

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