Mental neuropathy: report of five cases and review of the literature

Metastasis of malignant tumors to the oral cavity: Systematic review of case reports and case series

OBJECTIVE

To summarize published information regarding malignant tumors with metastasis to the oral cavity.

MATERIALS AND METHODS

This was a systematic review with meta-analysis. An electronic search of Pubmed, Scopus, and Google Scholar databases from inceptions to February 2022 were performed. Only case reports or case series with histopathological results demonstrating metastasis to the oral cavity were included. The main outcomes included demographics, primary site, metastatic site, clinical manifestations, and patient survival. The quality of primary articles was assessed using the Joanna Briggs Institute - University of Adelaide scorecards for case reports and case series. Descriptive analysis and a Kaplan-Meier survival curve were performed.

RESULTS

273 articles were selected (50 case series and 223 case reports), for a total of 950 cases. The mean age was 57.11 years. Males were more affected (57.5%). The most common primary sites in women and men was breast (29.8%), and lung (24.8%), respectively. In ∼1/3 of the cases, oral metastasis preceded tumor dissemination. Jawbones were more affected (56.7%) than soft tissues (37.9%), with the mandible being the most affected site (45.5%), followed by the gingiva (19.9%). The most common clinical manifestation was a mass or nodule. Most radiographic evidence was radiolucency of the jaw (60.6%). 3-year and 5-year survival rates were 14.2 and 10.7%. In the majority of cases, the primary tumor was the first to be diagnosed, while in 30.4%, metastasis was the first sign of the disseminated disease. This can be implied that the oral metastasis should be included in the differential diagnosis list of the oral diseases.

CONCLUSION

Clinicians should be aware of the possibility of, albeit uncommon, oral metastases. Because the extracted data in this review was relatively generalized, the investigators cannot develop the diagnostic clues of oral metastasis, which require further investigations.

Numb chin syndrome: What all oral health care professionals should know

BACKGROUND

Numb chin syndrome (NCS) is a rare sensory neuropathy involving the mental nerve. Symptoms of NCS are often overlooked because of their apparent innocent nature; however, owing to the frequent association of NCS with malignancies, the opposite should be the rule. Oral health care professionals may be the first to encounter patients with NCS and should be aware of its clinical characteristics in an effort to decrease patient morbidity and mortality.

TYPES OF STUDIES REVIEWED

A search in PubMed (MEDLINE) and the Cochrane Library was performed using the terms numb chin syndrome, numb chin, mental neuropathy, mental nerve neuropathy, and malignant mental nerve neuropathy, yielding 2,374 studies. After inclusion and exclusion criteria were applied, 102 studies remained. Descriptive statistics were performed, analyzing the etiology responsible for NCS, characteristics of NCS including associated symptoms, unilateral or bilateral nature, and information on professionals visited and examinations requested to make a diagnosis.

RESULTS

NCS was associated with malignancy in 29% through 53% of the published cases. Twenty-eight percent of patients initially consulted an oral health care professional with the symptom of a numb chin. Patients more likely to have NCS were those from the ages of 61 through 70 years; 74% were unilateral; and the most common symptoms reported were numbness (100%), paresthesia (18%), and pain (17%). Forty-seven percent of the NCS cases were associated with a recurrent malignancy, and the most prevalent associated diagnoses were breast cancer (32%) and lymphoma and leukemia (24%).

CONCLUSIONS

Oral health care professionals should be aware of the characteristics of NCS as they may be the first health care providers consulted for these symptoms.

PRACTICAL IMPLICATIONS

A thorough medical and dental history as well as a complete cranial nerve screening should be performed on all patients, especially those with numbness, as this may prevent misdiagnosis and allow a timely referral and a substantial improvement of treatment course and prognosis.

A Case of Sjögren's Syndrome Associated With Trigeminal Neuropathy and Enhancement of the Mandibular Nerve at the Foramen Ovale: A Case Report and a Review of the Differential Diagnosis and Mechanisms of the Disease

We describe a case of Sjögren's syndrome-associated trigeminal neuropathy with mandibular nerve enhancement at the foramen ovale and Gasserian ganglion (Meckel's cave) in a patient with a prior history of breast cancer. We also explore the differential diagnosis of trigeminal neuropathy associated with mandibular nerve involvement at the foramen ovale and exclude other diseases such as Sjögren's syndrome or perineurial invasion as a result of various carcinomas. We emphasize the importance of an investigative triad of searching for a local head-and-neck malignancy that may metastasize by perineural spread or invasion, excluding a distant malignancy or paraneoplastic phenomenon and ruling out an autoimmune etiology such as Sjögren's syndrome. In the process, we briefly outline the basic immunopathologic processes.

Numb chin syndrome secondary to infiltration of inferior alveolar nerve as a presentation of relapse in treated testicular lymphoma-diagnosis on PET/CT and MR neurography

Numb chin syndrome (NCS) is a rare presentation of primary or recurrent malignant neoplasms among other non-neoplastic causes. The syndrome is characterized by altered sensations in the distribution of the mental nerve and presents with pain and paresthesias along the distribution of the inferior alveolar nerve and its branches. The primary diagnosis is indicated while following up patients through positron emission tomography/computed tomography (PET/CT) when a hypermetabolic focus is seen in the vicinity of the angle of the mandible. Further anatomical localization is performed using magnetic resonance (MR) neurography and postcontrast MR imaging, which demonstrates neural involvement. We hereby describe a case of a 56-year-old man, a treated case of DLBCL (diffuse large B-cell lymphoma), presenting with NCS and diagnosed with perineural invasion through PET/CT and further MR evaluation. To our knowledge, there are no other reports in the literature describing the MR neurography appearance of the inferior alveolar nerve in NCS. We hereby stress on the use of MR neurography followed by postcontrast 3D sequences with multiplanar reformatting for adequate lesion detection.

Orofacial manifestations of sickle cell disease: implications for dental clinicians

Sickle cell disease is a multisystem disease associated with episodes of acute illness and progressive organ damage. It is one of the most common severe monogenic disorders worldwide and is now the fastest growing genetic disorder in the UK. Dental awareness of orofacial manifestation varies geographically due to the inheritance pattern and patient population affected by the disease. This article details the epidemiology, pathophysiology and the orofacial manifestations in light of current literature.

Numb chin syndrome in sickle cell disease: a case series of Jamaican patients

Numb chin syndrome is an uncommon presentation that has been reported as secondary to metastatic disease, trauma, and infections of the maxilla, mandible, or oral cavity. The hypoesthesia, paraesthesia, or pain are a result of injury to the inferior alveolar nerve, which is particularly vulnerable as it exits the mandible through the mandibular foramen as the mental nerve. In persons with sickle cell disease, it has been reported as a manifestation of mandibular vaso-occlusive crisis. This case series presents 13 patients with sickle cell disease who presented with numb chin syndrome, the largest number of cases that has been described in the literature to date. The report illustrates the wide variety of presentations and therefore possible differential diagnoses to consider. In this case series, the symptoms were associated with vaso-occlusive crises, allergic reactions, dental infections, malignancy, rheumatoid arthritis, and pregnancy. Most appeared to be self-limiting; however, one patient was having his second episode, and the numbness has persisted in three patients. The series illustrates that it is important not only to ensure that the source of the local vaso-occlusive crisis is treated, but also to not miss important differentials such as metastatic disease, where this can be the first presentation of malignancy and would represent a very poor prognosis. There is no reported successful treatment for the hypoesthesia in this case series, and this presents an area for further research.

Chameleons, red herrings, and false localizing signs in neurocritical care

False localizing signs (FLS) and other misleading neurological signs have long been an intractable aspect of neurocritical care. Because they suggest an incorrect location or etiology of the pathological lesion, they have often led to misdiagnosis and mismanagement of the patient. Here, we reviewed the existing literature to provide an updated, comprehensive descriptive review of these difficult to diagnose signs in neurocritical care. For each sign presented, we discuss the non-false localizing presentation of symptoms, the common FLS or misleading presentation, etiology/pathogenesis of the sign, and diagnosis, as well as any other clinically relevant considerations. Within cranial neuropathies, we cover cranial nerves III, IV, V, VI, VII, VIII, as well as multiple cranial nerve involvement of IX, X, and XII. FLS ophthalmologic symptoms indicate diagnostically challenging neurological deficits, and here we discuss downbeat nystagmus, ping-pong-gaze, one-and-a-half syndrome, and wall-eyed bilateral nuclear ophthalmoplegia (WEBINO). Cranial herniation syndromes are integral to any discussion of FLS and here we cover Kernohan's notch phenomenon, pseudo-Dandy Walker malformation, and uncal herniation. FLS in the spinal cord have also been relatively well documented, but in addition to compressive lesions, we also discuss newer findings in radiculopathy and disc herniation. Finally, pulmonary syndromes may sometimes be overlooked in discussions of neurological signs but are critically important to recognize and manage in neurocritical care, and here we discuss Cheyne-Stokes respiration, cluster breathing, central neurogenic hyperventilation, ataxic breathing, Ondine's curse, and hypercapnia. Though some of these signs may be rare, the framework for diagnosing and treating them must continue to evolve with our growing understanding of their etiology and varied presentations.

The "numb chin syndrome": A case report

INTRODUCTION

Neuroendocrine tumours comprise 0.5-2% of all malignancies in adulthood, and very rarely metastasize to the oral cavity. When they do metastasize to the oral cavity, the mandible is the most common site. This can lead to symptoms such as a numb chin and lip, which in the absence of any odontogenic cause may be an important sign indicating malignant disease. We present a rare case of metastatic neuroendocrine carcinoma to the mandible, resulting in the so-called "numb chin syndrome".

PRESENTATION OF CASE

An elderly lady presented with numbness to the right chin and lip, as well as hypoglossal nerve palsy. She had significant back pain and gave a history of repeat chest infections. Intra-oral clinical examination was normal, but upon further special investigations, the right mental region was suspicious of multiple lytic lesion. Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) demonstrated marrow changes in the mandible suspicious of malignant disease. Further findings included multiple pathological fractures of the spine and a mass in the left lung base. A trephine biopsy gave a diagnosis of metastatic neuroendocrine carcinoma, with the left lung mass considered to be the primary site.

DISCUSSION

We discuss the rarity of metastatic disease to the oral cavity, and the importance of "numb chin syndrome" in indicating malignancy.

CONCLUSIONS

This case promotes the importance of considering sinister pathology when presented with sudden, altered sensation to the chin and lips. The "numb chin syndrome" should always raise the suspicion of primary or metastatic disease to the mandible.

Multiple myeloma with multiple neurological presentations

Multiple myeloma is a haematological malignancy with clonal plasma cell proliferation and production of monoclonal immunoglobulins. Its neurological complications are relatively common, caused by both the disease and the treatment. Neurologists should therefore be familiar with its neurological manifestations and complications. We describe a 40-year-old woman who presented with lower cranial neuropathies mimicking variant Guillain-Barré syndrome, with normal brain and spinal cord imaging and cerebrospinal fluid (CSF) albuminocytological dissociation, and subsequently diagnosed with IgD myeloma. She relapsed repeatedly with differing neurological presentations: numb chin syndrome and twice with impaired vision, first from cerebral venous sinus thrombosis and later from leptomeningeal infiltration of the optic chiasm. We discuss the neurological complications of myeloma, emphasising the need to consider it in a wide variety of neurological presentations and repeatedly to reassess its associated neurological diagnoses. We also highlight the complexity of myeloma treatment.

Numb chin syndrome: an ominous sign of mandibular metastasis

A 51-year-old woman a known case of stage 2 breast carcinoma in 2006 and underwent left mastectomy performed in the same year presented with bilateral lower limb pain suggestive of spinal pathology, and left chin numbness, both of 2 weeks' duration. Examination revealed left mandibular hypoesthesia without any other sign or symptoms. Orthopantomogram was unremarkable apart from mild alveolar bone expansion at tooth 36 area, which was extracted 3 months earlier. Subsequently, a full-body positron emission tomography contrast enhanced computer tomography revealed hypermetabolic lesions of her axial (excluding skull) and appendicular skeleton. In the head and neck region, left mandibular foramen and oropharynx bilaterally showed increased metabolism suggestive of tumour metastasis. The diagnosis was numb chin syndrome secondary to mandibular metastasis. Apart from supportive treatment, she was started on palliative chemotherapy and radiotherapy. At the time of discharge, there were no active complaints other than the aforementioned hypoesthesia.

Numb Chin Syndrome Leading to a Diagnosis of Salivary Ductal Adenocarcinoma: A Case Report and Review of the Literature

Numb chin syndrome (NCS) refers to a rare sensory neuropathy characterized by numbness of the chin within the distribution of the mental or inferior alveolar nerve. Although NCS is usually caused by a benign process, it should not be underestimated and a thorough diagnostic evaluation for a new or known progressive malignancy should always be performed. Here, we report a case of salivary ductal adenocarcinoma that mimicked a pulpitis and periodontitis in its early presentation accompanied by numbness of chin. The course and diagnosis of this case are discussed, and a brief review of the literature is presented. It is hoped for clinicians to keep the malignant possibility of NCS in mind and take a thorough examination.

Numb chin with mandibular pain or masticatory weakness as indicator for systemic malignancy - A case series study

BACKGROUND/PURPOSE

Numb chin syndrome (NCS) is a critical sign of systemic malignancy; however it remains largely unknown by clinicians and dentists. The aim of this study was to investigate NCS that is more often associated with metastatic cancers than with benign diseases.

METHODS

Sixteen patients with NCS were diagnosed and treated. The oral and radiographic manifestations were assessed.

RESULTS

Four (25%) of 16 patients with NCS were affected by nonmalignant diseases (19% by medication-related osteonecrosis of the jaw and 6% by osteopetrosis); yet 12 (75%) patient conditions were caused by malignant metastasis, either in the mandible (62%) or intracranial invasion (13%). NCS was unilateral in 13 cases and bilateral in three cases. Mandibular pain and masticatory weakness often dominate the clinical features in NCS associated with cancer metastasis. In two patients, NCS preceded the discovery of unknown malignancy (breast cancer and leukemia). In nine others, NCS heralded malignancy relapse and progression. Metastatic breast cancer in four (36%) cases accounted for the most common malignancy. Other metastatic diseases included two multiple myelomas, and one each of leukemia, prostate cancer, colon cancer, lung cancer, maxillary sinus adenoid cystic carcinoma and adrenal gland neuroblastoma. Radiographic examinations showed obvious mandibular metastasis with compression of the inferior alveolar nerve or mental nerve in nine patients, and leptomeningeal seeding or intracranial metastasis to the trigeminal nerve root at the skull base in two patients.

CONCLUSION

NCS without obvious odontogenic causes or trauma often signals systemic malignancy. It may be the first clue of occult malignancy.

Numb chin syndrome as a manifestation of jaw metastasis diagnosed in a bone scan

In many cases, numb chin syndrome (NCS) may represent a banal pathology. However, as it can be associated with malignant processes, its presence should alert the clinician of a possible occult disease. In patients already diagnosed with cancer, it often represents an ominous sign that indicates poor prognosis, due to the rapid progress of the disease. The case is presented of a 62-year-old man diagnosed with synchronous lung and bladder cancer, who suddenly complained of numbness in the chin. The bone scan confirmed the suspicion of metastastic bone disease, and the patient died two months after the appearance of this sign.

Neuropathies associated with lymphoma†

Neuropathy occurs with various manifestations as a consequence of lymphoma, and an understanding of the etiology is necessary for proper treatment. Advances in medical imaging have improved the detection of peripheral nerve involvement in lymphoma, yet tissue diagnosis is often equally important. The neoplastic involvement of the peripheral nervous system (PNS) in lymphoma can occur within the cerebrospinal fluid (CSF), inside the dura, or outside of the CSF space, affecting nerve root plexuses and peripheral nerves. The infiltration of either cranial or peripheral nerves in lymphoma is termed neurolymphomatosis (NL). These infiltrations can occur as mononeuropathy, multifocal neuropathy, symmetric neuropathies, or plexopathies. In rare cases, intravascular lymphoma (IL) can affect the PNS and an even rarer condition is the combination of NL and IL. Immune-mediated and paraneoplastic neuropathies are important considerations when treating patients with lymphoma. Demyelinating neuropathies, such as Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy, occur more frequently in non-Hodgkin's lymphoma than in Hodgkin's disease. Paraproteinemic neuropathies can be associated with lymphoma and paraneoplastic neuropathies are rare. While the treatment of lymphomas has improved, a knowledge of neurotoxic, radiotherapy, neoplastic, immune-mediated and paraneoplastic effects are important for patient care.

Numb Chin Syndrome

"Numb chin syndrome" (NCS) refers to new-onset numbness of the lower lip and chin within the distribution of the mental or inferior alveolar nerves. While this focal numbness may be downplayed or even overlooked by patients and clinicians, in the right clinical scenario this may be the presenting symptom of an underlying malignancy. In the absence of any obvious, temporally related dental cause, there are certain conditions that clinicians should consider including orofacial and systemic malignancies as well as several inflammatory disorders. Thorough diagnostic evaluation should always be performed when no clear cause is evident. This paper will discuss the differential, recommended evaluations, and the prognosis, for a patient presenting with NCS.

Mental nerve neuropathy: case report and review

Mental nerve neuropathy (MNN) or “numb chin syndrome” is a rare neurologic symptom most often associated with malignancy. Patients typically develop paresthesia or numbness localized to the chin and lower lip and will often seek care at their local emergency department. Pain and expansion of the lower jaw may also be present. We report a case of MNN associated with a metastatic lesion in the mandible. The purpose of this article is to highlight the importance of recognizing MNN, a potentially life-threatening symptom of metastatic carcinoma, and enable clinicians to properly diagnose MNN, which may mimic other conditions that affect the mandible.

Numb chin syndrome secondary to leptomeningeal carcinomatosis from gastric adenocarcinoma

Numb chin syndrome (NCS) can be a sign of malignancy. Its association with gastric adenocarcinoma is rare. We report a case of a 27-year-old Hispanic female that presented with complaint of left sided headache associated with numbness of the left side of chin and lower gingiva. Initial brain MRI, whole body gallium scan, high resolution CT of chest and elevated protein in the CSF were suggestive of sarcoidosis. She was treated with IV steroids with transient clinical improvement. Two weeks later, her symptoms worsened and further evaluation revealed the diagnosis of a poorly differentiated metastatic gastric adenocarcinoma with leptomeningeal involvement. This case report aims to emphasize the importance of identifying NCS as a possible indication of an underlying malignant condition. Reported cases of NCS associated with metastatic gastric adenocarcinoma are very rare.

Metastatic tumors to the jaws and mouth

Metastatic dissemination to the oral cavity is rare and is usually the evidence of a wide spread disease with an average survival rate of 7 months. In almost a quarter of the cases, oral metastasis was found to be the first indication of an occult malignancy at a distant site. Metastatic lesions can be found anywhere in the oral cavity, however, the jaw bones with the molar area is the most frequently involved site. In the oral soft tissues, the gingiva is the most common site, suggesting the possible role of inflammation in the attraction of metastatic deposits. The most common primary malignancies presenting oral metastases were the lung, kidney, liver, and prostate for men, and breast, female genital organs, kidney, and colo-rectum for women. Most patients with jawbone metastasis complain of swelling, pain, and paresthesia. An exophytic lesion is the most common clinical presentation of metastatic lesions in the oral soft tissues. Early lesions, mainly those located in the gingiva, may resemble a hyperplastic or reactive lesion. Once a lesion is recognized as metastasis, the primary tumor site should be identified following clinical, radiological and histopathological investigations. If standardized diagnostic workup fails to detect the site of origin, then the term carcinoma of unknown primary is applied. Personalized medicine tools such as tissue-of-origin assays should be applied, either by immunohistochemical testing or by molecular-profiling methods as these may lead to a more favorable outcome.

Numb chin syndrome: a case series of a clinical syndrome associated with malignancy

INTRODUCTION

Information regarding the appropriate work-up and outcomes in patients receiving palliative treatment for numb chin syndrome (NCS) in the setting of malignancy is sparse. This study aims to describe NCS in malignancy and evaluate the disease trajectory, significance of diagnostic modalities and outcomes with palliative treatment.

METHODS

A retrospective study was performed on patients presenting with NCS between March 2007 and October 2013 at the Capital Region Cancer Service, Canberra.

RESULTS

Thirteen patients were identified who presented with numbness of the chin between March 2007 and October 2013. Seven patients had breast cancer, two had prostate cancer, two had multiple myeloma, one had medulloblastoma and one had an adenoid cystic salivary gland tumour. The mean interval from initial cancer diagnosis to development of the syndrome was 4.32 years. Twelve out of 13 patients had had prior chemotherapy with two or more lines of treatment (with a median of two lines), indicating this condition tended to present late in the course of disease in our patients. Four patients developed bilateral symptoms, and in two of these cases the metastatic lesion was in the base of the skull. Eleven out of 13 patients had positive signs on imaging. Nine out of 13 patients received palliative radiotherapy, with clinical response in eight patients.

CONCLUSION

Patients with malignancy presented with NCS late in the disease trajectory, often after multiple lines of treatment. In our cohort of patients, 84% had positive imaging signs to aid diagnosis, and 77% had resolution of numbness with palliative treatment.

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

INTRODUCTION

Numb 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 CASE

This 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.

DISCUSSION

NCS can oftentimes present itself in the absence of mandibular or base of skull metastatic lesions.

CONCLUSION

NCS can be a sign of underlying advanced metastatic malignancy and therefore cannot be ignored and must be investigated fully.

Orofacial manifestations in patients with sickle cell disease

BACKGROUND

The aim of this study was to review the orofacial manifestations in patients with sickle cell disease (SCD).

METHODS

Indexed databases were explored using various combinations of the following keywords: "sickle cell anemia," "sickle cell disease," "oral health status" and "dental inflammation."

RESULTS

Hypoxia has been associated with osteomyelitis of the jaws, particularly the mandible in patients with SCD. Bone marrow hyperplasia in these patients causes depression of nasal bridge, midfacial overgrowth and malocclusion. Mental nerve neuropathy due to osteomyelitis of the mandible causes numbness in the lower lip and chin. A diminished blood supply to teeth causes necrosis of the dental pulp in patients with SCD. Dental caries is a common manifestation in patients with SCD, particularly in those with underprivileged living standards. The association between SCD and periodontal inflammatory conditions remains unclear.

CONCLUSIONS

Oral health problems in patients with SCD are rare and occur mainly as a result of the poor oral hygiene maintenance.

Bilateral mental nerve neuropathy in an adolescent during sickle cell crises

Mental nerve neuropathy causes the "numb chin" syndrome and is usually associated with mandibular bone injury or disease in adults. It has been reported in adults during sickle cell crises. We describe a 15-year-old boy who developed bilateral mental nerve neuropathies during a sickle cell crisis. This case is unusual because of the simultaneous bilateral involvement and because of the age.

Numb chin syndrome with vagal and hypoglossal paralysis: an initial sign of an uncommon diagnosis

In this study, the case of a 58-year-old man with a 2-month history of left chin paresthesia with difficulty swallowing and chewing, and dysphonia is reported. He had an absence of the gag reflex, unilateral palatal palsy and deviation of the tongue upon attempted protrusion with unilateral atrophy. Magnetic resonance imaging of the skull base revealed a tumoral infiltration of the left side of Meckel's cave, involvement of the clivus with extension into the cavernous sinus and signs of focal leptomeningeal infiltration. The patient was eventually diagnosed with generalized Burkitt's lymphoma. In this study, the authors suggest an initial diagnostic workup that includes a computed tomography scan of the mandible and a magnetic resonance imaging of the skull base searching for malignancy in patients with isolated numb chin syndrome, a rare disorder often associated with cancer, especially breast cancer and lymphoma, with mandibular metastases, leptomeningeal seeding and metastases of the base of the skull explaining the origin of the syndrome in most cases.

Non-Hodgkin lymphoma presenting with numb chin syndrome

Numb chin syndrome (NCS) is a rare yet potentially ominous sensory neuropathy characterised by unilateral hypoesthesia or paraesthesia over the lower lip, chin and occasionally gingival mucosa. Recognising NCS clinically is important as this may be a subtle sign of occult malignancy progression or relapses. Current expert opinion is that patients with NCS without apparent cause should be assumed to have a malignant aetiology until proven otherwise. By far the most common non-haematologic neoplastic cause of NCS is breast cancer, while the most common haematologic neoplastic cause is non-Hodgkin lymphoma (NHL). The pathophysiology of NCS has been shown to be either direct compression of the mental nerve by tumour mass, leptomeningeal invasion or a bony lesion at mental foramen. Here we report a case of NHL presenting with NCS with no evidence of metastasis in brain parenchyma, cerebrospinal fluid or mandibular bone. Instead, diffuse dural thickening and focal lesion in clivus were identified. We propose that these may represent novel mechanisms of NCS.

Numb chin syndrome: an ominous clinical sign

Numb chin syndrome (NCS) is a rare but important clinical symptom and sign. It describes a condition presenting as anaesthesia or paraesthesia over the chin, which is usually unilateral. The condition manifests spontaneously with no history of trauma, infection or obvious odontogenic cause. NCS is a clinically important finding as it may be the primary manifestation of Multiple Sclerosis (MS) or sign of systemic malignancy. We present a case of a 58-year-old gentleman who was referred to a regional oral and maxillofacial unit with a three-month history of sudden onset unilateral numbness of the chin. No odontogenic cause could be found and subsequent CT/PET scan from the cerebellum to the upper thighs revealed evidence of widespread metastatic disease. The patient died five weeks after his initial presentation. We discuss the importance of this clinical symptom, the likely mechanism of disease and offer differential diagnoses. Additionally, we recommend that patients presenting to their general dental practitioner with a numb chin be urgently investigated for a potentially undiagnosed malignancy or MS and be referred to their local oral and maxillofacial unit as an urgent 'target' referral.