Oral lesions may present with or without symptoms and require close monitoring and often intervention by an Oral Maxillofacial Surgeon. Many oral lesions are benign but in those that are malignant, they are often primary lesions and rarely from metastasis. We present a case of a lesion in the soft palate of a completely edentulous lung adenocarcinoma patient on pembrolizumab. At the time of presentation, his lung cancer was thought to be well-controlled with immunotherapy. His oral lesion was biopsied and initially reported to be “poorly-differentiated carcinoma.” Given his history of lung adenocarcinoma, through immunohistochemical comparison of the palatal specimen with previous lung specimen, the findings supported metastatic lung adenocarcinoma to the soft palate.
Metastatic lung adenocarcinoma to the palate is rare.
Biopsy should be considered for a non-healing palatal sore.
Palatal specimen staining positive for pancytokeratin, TTF-1, and CK7 may support a pulmonary origin.
Metastatic neoplasms to the oral cavity represent 1–3% of all oral malignancies [ ] and may be encountered by the dentist. Common primary sites differ between sexes: For men, these metastatic lesions may come from lung, kidney, liver, and prostate primaries. For women, they commonly come from breast, genital organs, kidney, and colorectum primaries. Oral lesion was the first sign of an occult malignancy at a distant site in about 25% of metastatic cases [ ].
According to data from National Center for Health Statistics, lung cancer represented the second most new cases (14%) of cancer for men in the USA. Lung cancer was found to be the leading cause of cancer-related deaths in both men and women [ ]. Lung adenocarcinoma accounts for approximately one-third of cases of lung cancer [ ].
In this case study, we present a patient, with a history of lung adenocarcinoma thought to be well-controlled with chemotherapy, who came to our clinic with a palatal lesion. The lesion was biopsied, and the initial histologic analysis was thought to represent a new primary of oral squamous cell carcinoma. Through immunohistochemical (IHC) comparison between the palatal specimen and the previous lung specimen, the findings suggested metastatic lung adenocarcinoma to the palate.
A 71-year-old edentulous male presented to our oral maxillofacial surgery clinic, on referral from his primary dentist, with a chief complaint of an inability to wear his upper denture due to a sore on his right palate present for 2–3 months. The patient stated that the lesion caused mild to moderate pain and was slowly enlarging.
His past medical history consisted of atrial fibrillation, chronic obstructive pulmonary disease, lung cancer for which he received chemotherapy (was on pembrolizumab at time of presentation) and post-traumatic stress disorder. His social history was significant for 50 pack years of smoking tobacco, alcohol abuse and cannabis abuse. His medications included apixaban, pembrolizumab, levothyroxine and metoprolol succinate.
On exam, the patient had a 2 cm × 1.5 cm erosive appearing lesion ( Fig. 1 ) at the junction of his hard and soft palate on the right side. The lesion was mildly tender to palpation and bleed slightly with manipulation. There was no palpable cervical or submandibular lymphadenopathy or masses clinically. A panoramic radiograph ( Fig. 2 ) of the area was equivocal and a computed tomography (CT) scan was obtained ( Figs. 3–5 ).