Unusual presentation of ‘numb chin syndrome’ as the manifestation of metastatic adenocarcinoma of the lung

Abstract

INTRODUCTIONNumb chin syndrome (NCS) is the presence of hypoaesthesia or paraethesia of the lip and chin over the distribution of the mental nerve. It is often caused by the presence of a metastatic tumour in the mandible or the base of skull and represents advanced malignancy.PRESENTATION OF CASEThis paper presents an unusual case of NCS associated with metastatic adenocarcinoma of the lung, for which no obvious lesion was found in the mandible or base of the skull.DISCUSSIONNCS can oftentimes present itself in the absence of mandibular or base of skull metastatic lesions.CONCLUSIONNCS can be a sign of underlying advanced metastatic malignancy and therefore cannot be ignored and must be investigated fully.

Numb chin: A simple sign of a catastrophic illness

“…[1][2][3][4][5][6][7][8][9][10] This is one of the terminal branches of the mandibular division of the trigeminal nerve. [11] The mental nerve is responsible for supplying the skin of the chin and lower lip and the mucous membranes on the buccal surface of the lower lip.…”

“…This damage can be a result of traumatic injuries, infections, metabolic problems, inherited causes, tumours and exposure to toxins. [1][2][3][4][5][6][7][8][9] The cranial nerves are those that arise directly from the brain or brainstem and often affect areas such as the face and eyes. The sensory neuropathy of the mental nerve (Numb Chin Syndrome-NCS) is a rare neurological condition, often associated with malignancy, as a sentinel clinical presentation.…”

“…The sensory neuropathy of the mental nerve (Numb Chin Syndrome-NCS) is a rare neurological condition, often associated with malignancy, as a sentinel clinical presentation. [1][2][3][4][5][6][7][8][9][10][11][12][13] The most common primary tumours related to it are lymphoma and breast cancer. [7] There are reported cases where there were no history of tumours and it was due to the onset of this symptom that the investigation commenced was conducted.…”

“…[3,8,[11][12][13] Therefore, the NCS is a sign that can be extremely important and reveal a hidden tumour and this research should begin using the many complementary diagnostic tests that are available today, because early recognition can have an impact on patient's quality of life. [6,8,11,12] …”

Numb Chin Syndrome as the First Symptom of Diffuse Large B-cell Lymphoma

“…6,9) Although this is a rare disease, the fact that it can be the first symptom of malignant tumor makes the role of clinicians on early diagnosis critical. 4,10) This symptom can be triggered without a reason and affects the area of distribution of inferior alveolar nerve with no history of trauma and dental problems. In conclusion, NCS without apparent causes should be considered a red flag symptom of a malignant tumor and investigated without delay.…”