Metastasis from the prostate gland to the mandible is rarely encountered and commonly present with non-specific features like unexplained pain, swelling, and numb chin syndrome. Here we present a case with metastatic prostate adenocarcinoma detected secondary to oral manifestations. Patients present with unexplained facial pain and numbness should alert clinicians to the presence of malignant disease, and appropriate hematological, radiological and or histological investigations should be performed. Thereby, clinicians can prevent the overlook of the first signs of metastasis, accelerate the early diagnosis and positively orientate the prognosis of the disease, especially in a patient without known malignancy.

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 (NCS) is defined as reduced or absent sensation in an area of the chin and lower lip within the distribution of the mental or inferior alveolar nerves. The causes of NCS may be neoplastic, traumatic, dental, toxic, drug-induced, inflammatory, autoimmune or infectious. NCS may be the preliminary symptom of malignancy or recurrence/metastasis in patients with cancer. Therefore, the occurrence of NCS warrants careful examination and monitoring of such patients. This article presents two cases of NCS reported in a patient with prostate cancer and in a patient with Burkitt lymphoma/leukaemia.

Numb chin syndrome may be the manifestation of a local dental pathology or secondary to a systemic disease. A systematic physical examination with diagnostic workup is of utmost importance in patients presenting with numb chin syndrome. We report the case of a 58-year-old woman who presented with numb chin syndrome. An orthopantogram and computed tomography of the head revealed osteolytic lesion in the left molar region. Histopathological and immunohistochemical examination confirmed the lesion to be metastatic breast carcinoma. Breast ultrasound scan demonstrated a 1.5 × 1.5-cm lesion in the left breast and fine needle aspiration cytology from the lesion confirmed the diagnosis of breast carcinoma. Bone scan showed multiple bone metastases. She was diagnosed to have numb chin syndrome secondary to bone metastases from breast carcinoma. In view of her disseminated disease status, she was started on palliative hormone therapy (Letrozole) with zoledronic acid. We present this case to highlight the importance of careful evaluation of patients presenting with numb chin syndrome because this may be the only manifestation of a systemic malignancy.

Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin's lymphoma that classically presents with rapidly enlarging lymph nodes. We present a 59-year-old man with unusual clinical presentation of numb chin syndrome (NCS) as the first symptom of disease. On evaluation, he was found to have diffuse extranodal skeletal involvement in the form of lytic-sclerotic lesions and minimal lymphadenopathy. Bone marrow biopsy revealed a poorly differentiated tumour with infarction and extensive myelofibrosis. This was subsequently proven to be DLBCL of germinal centre type on immunohistochemical stain. NCS should alarm the clinician to investigate for an advanced underlying malignancy. Extensive myelofibrosis, though described in carcinomas and low grade lymphomas, may also be seen in high grade DLBCL.

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.