Introduction. Cancer of unknown primary (CUP) is histologically defined as the presence of a metastasis of lymph node without detection of the primary tumor [1]. Approximately 3–15% of all cancers are designated as CUP [3. 4]. The diagnosis, treatment and monitoring of patients with laterocervical metastases of unknown primary involves a wide range of oncologic entities [5]. While we were studying patho-histological examination of cervical lymphadenopathy in Mongolian, werevealed unknown primary tumor. This is a goal of our study. Objectives of study are followings to differentiate whether primary lymphoma or metastatic cancer of cervical lymph node metastasis of unknown primary tumor and to reveal primitive origin of tumor using by basic and additional immunohistochemical markers.Goal.To determine the conclusive diagnosis in cervical lymph node metastasis of unknown primary origin by immunohistochemical techniqueMaterials and Methods. In this study, we examined immunohistochemically 30 cases of outpatient head and neck surgical unit of the National Cancer Center and dentistry and oral maxillofacial surgical unit of the State Central Hospital which were diagnosed as cervical lymphadenopathy. For immunohistochemical study, we applied an immunohistochemical panel in accordance with avidinbiotin- peroxidase complex method and used a basic and additional antibodies represented by CK(pancytokeratin), LCA, synaptophysin, chromogranin and HMB45. Result. In our study, there was 63.3% lymphoma, 36.7% metastatic cancer. Among them, there were 4 of digestive tract adenocarcinoma, 3 of squamous cell carcinoma /2-esophagus, 1-nasopharyngeal/, 2 of neuroendocrine tumor and 1 of melanoma.Distribution by age groups shows that 20-29 years were 4(13.3%), 30-39 years were 10 (33.3%), 40-49 years were 8 (26.7%), 50-59 years were 3 (10%), over60 years were 5 (16.7%). Gender distribution showed an increased incidence of males (56.7%, 17 cases) compared with females (43.3%, 13 cases).Conclusion: In our study, B cell lymphoma and digestive tract adenocarcinoma were the most common. In further, it is necessary to introduce an immunohistochemical method in patho-histological practice.

BACKGROUND The occurrence of facial injuries tends to be high compared to injuries in other parts of the body, because the face is without a protective covering, and the chin mandible is the most prominent bone in this region of the body. According to several studies, mandibular fractures account for 59% of all facial fractures. Mandibular fractures usually occur in 2 or more locations because of the bone’s U shape. This article aims to analyze retrospectively the age, gender, etiology, and anatomic distribution of mandibular fractures. METHODS The data for this study were obtained from the medical records of 1217 cases treated at Department of Oral and Maxillacial Surgery at National First Central Hospital of Mongolia in 2016. Information was collected from the clinical notes of each patients with mandible fractures. The demographic variables such as age, gender and clinical information included diagnosis, etiology, and anatomical distribution of fractures was assessed. RESULTS The total of 229 subjects had mandible fractures, out of which 209 were males and 20 were females. The mean age of the participants was 32,2±10. The major cause of fractures was assault 79% , followed by road traffic accident – 11%, sport injuries – 5%, accidents at work or home – 3%, other – 2%. Mandible fracture incidence were high during in August. By the time referred to a physician from day of injury were 1-5 days 72,1%, 6-10 days 25,7%, delayed more than 10 days were 2,2% of the cases. Unilateral fractures were 77,4%, bilateral fractures 21,7%. Mandible left side were 158 (65,9%) mostly injured. The most common fracture site was angle- 112 (53%), condyle- 58 (27,5%), body- 21 (9,9%), parasymphysis- 16 (7,6%) and at least common site were ramus- 2 (1%) and symphysis - 2 (1%) of mandible. Among multiple fractures most common sites were condyle-parasymphysis which 24 cases and angle – parasymphysis were 21 cases. CONCLUSION The following conclusions have been drawn from the foregoing study. The mandible fractures were more common in males 209 (91,3%) than females 20 (8.7%). Assaults were the most common cause of the fracture. 77,4% fractures were unilateral fractures. The most common site of fracture was mandible angle- 112 (53%) and common multiple fractures were condyle-parasymphysis. By the time referred to a physician from day of injury were 1-5 days 72,1%, 6-10 days 25,7%, delayed more than 10 days were 2,2% of the cases.