Salvage surgery after radiation therapy is known to be associated with a high incidence of postoperative complications. We describe a case of a successful salvage surgery after BNCT. In our patient with head and neck carcinoma, cervical lymph node recurrence with adhesion to a large vessel occurred after conventional radiotherapy. This lesion responded well to BNCT. Salvage surgery was subsequently performed to remove the residual tumor. Histopathologically, the isolated tissue contained tumor cells in its center and the surrounding tissue showed severe fibrosis. However, the tissue outside of the irradiation area had almost no fibrosis. BNCT may facilitate salvage surgery after radiotherapy because it causes less injury to the surrounding tissue than conventional radiotherapy. Our experience suggests that BNCT may be a feasible preoperative treatment in patients with inoperable lesions or in those who strongly desire preservation of function.

BACKGROUND: Head and neck photoimmunotherapy specifically destroys tumor cells by irradiating them with 690 nm red light after administering cetuximab sarotalocan sodium. The key point in the technique of photoimmunotherapy is to set the irradiation area precisely with a margin added to the target lesion while securing a safety zone with large vessels such as the internal carotid artery.
METHODS: At our Institution, we performed photoimmunotherapy in combination with use of a navigation system on a male patient in his 70s with maxillary gingival carcinoma who had a recurrent lesion deep in the lateral pterygoid muscle. Three months after photoimmunotherapy, the superficial lesion had disappeared, the area of contrast within the lateral pterygoid muscle had improved, and the patient was deemed to have a complete response.
CONCLUSIONS: The Navigation System was successfully used in combination with photoimmunotherapy. Additionally, this allowed the location of the internal carotid artery to be confirmed in real time.

Photoimmunotherapy (PIT) targets and destroys tumor cells through irradiation with 690-nm red light after the administration of cetuximab sarotalocan sodium, which contains IRDye700DX bound to cetuximab. In Japan, PIT is a new treatment that is covered by insurance only for unresectable head and neck cancers. However, this treatment has conditional early approval. There have been no case reports describing the efficacy of this treatment in a real-world setting thus far. We report our experience with PIT for head and neck cancer. A 76-year-old man with laryngeal cancer underwent radiation therapy and surgery. Skin involvement in the right submandibular region was subsequently noted. We diagnosed local recurrence and performed PIT for this lesion. Partial response was achieved after the first PIT session, and progressive disease was diagnosed after the second session. Many aspects of PIT remain unclear and should, therefore, be clarified in further research. Despite this uncertainty, PIT may become an effective treatment strategy for head and neck cancer if the patient selection criteria are delineated.

BACKGROUND: Distant Metastases from Head and Neck Squamous cell carcinomas are uncommon (9-11%) and they are usually found in the lung and less frequently in the liver, kidney and adrenals. Central nervous system (CNS) metastases are extremely rare (2-8%), and they are described mainly in patients who already have extracranial metastases. So there\'s scarcity of data about their optimal management .
RESULTS: A patient presented CNS metastases after having been successfully treated with induction chemotherapy and definitive radiotherapy for a pyriform sinus carcinoma. The patient\'s work up, treatment and outcome are described.
CONCLUSIONS: CNS metastases from Head and Neck carcinomas are exceptionally rare. Nevertheless, clinicians should be alert of neurological symptoms in these patients, in order to set up a timely assessment and treatment. Secondarily, given the rarity of this condition, additional research on this topic is warranted in order to improve therapeutic strategies and outcomes of such patients.

BACKGROUND: Primary neuroendocrine carcinomas are uncommon head and neck malignancies. Their classification is still debated. We report four cases of unusual primary locations of neuroendocrine carcinomas of head and neck region emphasizing two entities and rare sites that were never described in the literature to the best of our knowledge.
UNASSIGNED: We reported four different cases of neuroendocrine carcinomas (nasal cavity, larynx, lymph nodes and tonsil) treated in our institution. The diagnosis was made by biopsy and confirmed by Immunohistochemical study. We underscored 2 atypical and rare entities in their location and anatomo histopathological type. Chemotherapy and radiotherapy were proposed for patients with nasal\'s and laryngeal locations. This latter had also undergone surgery. For lymph node location, the patient received decompressive radiotherapy alone. The patient diagnosed with neuroendocrine carcinoma of the tonsil didn\'t get any treatment except initial tonsillectomy for diagnosis purposes. Regarding the evolution in our case series, 2 patients had a relapse with local and regional metastasis. Among the 4 patients, 50 % passed away, one is still alive with deterioration of his general status and one is lost to follow-up and refused undergoing further investigations.
CONCLUSIONS: There is confusion in the literature regarding the classification of neuroendocrine carcinomas. According to the 2005 WHO, these lesions, can be subdivided into TC, AC (including LCNEC), SmCC, combined SmCC with nonsmall cell carcinoma, and paraganglioma. Their treatment is still debated. Through an overview of the literature, we have gathered the main studies and 2 meta-analysis summarizing the mainstay treatment and disease\'s outcome.
CONCLUSIONS: Neuroendocrine carcinomas of head and neck region are aggressive tumors with poor prognosis, low incidence and their diagnosis is not obvious. The treatment protocol depends on the type, the site of the lesions, and metastasis status. It\'s still not well codified.

Human papillomavirus (HPV)-related multiphenotypic sinonasal carcinoma is a distinct, recently described neoplasm of salivary gland nature that has an unusual microscopic appearance exhibiting multidirectional differentiation. Originally described by Bishop et al. in 2012, this distinct form of head and neck cancer is a very rare entity that few pathologists have encountered in practice, and only 50 cases have been reported in the literature. It usually presents as a large, destructive mass confined to the nasal cavity or paranasal sinuses, and is always associated with high-risk HPV infection. Although histologically it often resembles adenoid cystic carcinoma, this neoplasm also consistently exhibits features of myoepithelial, ductal and squamous differentiation. Newly recognized characteristics have recently been described that include bizarre pleomorphism, sarcomatoid transformation, and heterologous cartilaginous differentiation. These unique features have continued to expand the morphologic spectrum of this neoplasm and justify the recent change in its nomenclature from \"HPV-related carcinoma with adenoid cystic-like features\" to \"HPV-related multiphenotypic sinonasal carcinoma (HMSC)\". In 2017, \"HPV-related carcinoma with adenoid cystic like features\" was included as a provisional tumor type by the World Health Organization Classification of Head and Neck Tumors. Despite the presence of high-grade histologic characteristics such as necrosis and brisk mitotic activity, and a tendency for recurrence, HMSC demonstrates indolent clinical behavior and carries a good prognosis.

BACKGROUND: SMARCB1-deficient sinonasal carcinoma (SDSC) is an aggressive subtype of head and neck cancers that has a poor prognosis despite multimodal therapy. We present a unique case with next generation sequencing data of a patient who had SDSC with perineural invasion to the trigeminal nerve that progressed to a brain metastasis and eventually leptomeningeal spread.
METHODS: A 42 year old female presented with facial pain and had resection of a tumor along the V2 division of the trigeminal nerve on the right. She underwent adjuvant stereotactic radiation. She developed further neurological symptoms and imaging demonstrated the tumor had infiltrated into the cavernous sinus as well as intradurally. She had surgical resection for removal of her brain metastasis and decompression of the cavernous sinus. Following her second surgery, she had adjuvant radiation and chemotherapy. Several months later she had quadriparesis and imaging was consistent with leptomeningeal spread. She underwent palliative radiation and ultimately transitioned quickly to comfort care and expired. Overall survival from time of diagnosis was 13 months. Next generation sequencing was carried out on her primary tumor and brain metastasis. The brain metastatic tissue had an increased tumor mutational burden in comparison to the primary.
CONCLUSIONS: This is the first report of SDSC with perineural invasion progressing to leptomeningeal carcinomatosis. Continued next generation sequencing of the primary and metastatic tissue by clinicians is encouraged toprovide further insights into metastatic progression of rare solid tumors.

BACKGROUND: Patients with head and neck carcinoma are considered to be at high risk of developing tuberculosis, since the risk of morbidity due to tuberculosis in these patients is 2.86 to 16 times the risk in the general population.
METHODS: This case series describes an 83-year-old Japanese man, a 60-year-old Japanese man, and a 69-year-old Japanese man who developed active pulmonary tuberculosis while being treated for head and neck carcinoma. Two had previously developed tuberculosis and were treated for more than 50 years, but no symptoms or imaging findings suggested tuberculosis onset in the patients at initiation of treatment for head and neck carcinoma. Initially, local radiotherapy was performed for all three patients. Chemotherapy was continued for two patients who had pulmonary metastasis since initial consultation. For the other patient, surgery was performed for recurrence. In all three cases, active tuberculosis infection was observed during maintenance chemotherapy or immediately following surgery.
CONCLUSIONS: Due to the high risk of developing tuberculosis, the possibility of prophylactic administration of anti-tuberculosis agents to patients with head and neck carcinoma should be investigated, although prophylactic administration is not a cost-effective option for all patients with head and neck carcinoma. However, if tuberculosis onset occurs, it leads to various problems; it has a major impact on not only patients with cancer but also various people in the social environment. In the future, it is essential to consider prophylactic administration in patients requiring long-term maintenance drug therapy, especially in those who are treated at out-patient chemotherapy clinics, where there are several patients with cancer with low disease resistance.