the cases reported involved metastasis from cutaneous or mucosal melanoma , gastric adenocarcinoma , hypernephroma , and various lung neoplasms . the less common metastatic tonsillar tumors originate from mesothelioma , hepatocellular carcinoma , ovarian androblastoma , seminoma , anaplastic thyroid carcinoma , pancreatic adenocarcinoma , prostatic adenocarcinoma , and gall bladder carcinoma . breast carcinoma is one of the rarest primary tumors that can metastasize to the tonsil ; only eight cases have been reported in the literature , and only one case of tonsillar metastasis of breast sarcoma has been reported . tonsillar metastasis rarely becomes apparent before the diagnosis of the primary neoplasm , and only a few cases of tonsillar metastasis as a presenting feature have been reported in the literature . in most of these cases , the presenting symptoms were sore throat , an oral globus sensation , and different degrees of dysphagia and odynophagia . in other cases , patients were asymptomatic , and their tonsillar neoplasm was detected incidentally during a routine oral examination . tonsillar metastasis can be bilateral or unilateral depending on the nature of the primary neoplasm . the prognosis for patients with tonsillar metastasis is rather poor . in this report , we present a case of a phyllodes tumor that metastasized to the tonsil ; we have included the clinical features and pathological findings . a 54-year - old woman underwent right mastectomy for a breast tumor 3 years before she was referred to our department . histopathological examination showed a tumor larger than 10  cm in diameter that had slightly invaded the surrounding tissues and was characterized by moderate nuclei pleomorphism , moderate cell density , and moderate mitosis ( fig . the final pathology revealed that no tumor was identified on the margin of the resected specimen . immunostaining showed that the tissue was negative for cytokeratin ae1/ae3 , mnf116 , and cam5.2 . although she was informed of possible recurrence , she stopped ambulatory care 4 months after the operation . two years and 10 months after the operation , she presented with cough and dyspnea . a biopsy of the lung tumor was performed with bronchoscopy , and the sample was diagnosed as metastasis of the phyllodes tumor . pathology analysis of the lung specimen indicated metastasis of the malignant phyllodes tumor with incomplete resection . three years and 1 month after the lung operation , the patient was referred to our department for throat pain and presented with left tonsil swelling . physical examination revealed a left tonsillar tumor measuring 20  mm in diameter . computed tomography images showed a left tonsillar tumor that did not spread outside the pharyngeal constrictor muscles . pathology analysis of the biopsy of the left tonsil showed metastasis of the malignant phyllodes tumor of the breast . histopathological analysis of the left tonsillar tumor showed growth of spindle cells , necrosis , and atypical nuclei ( fig . immunostaining showed that the tissue was negative for cytokeratin ae1/ae3 , mnf116 , and cam5.2 . because the pathological features of the left tonsillar tumor were similar to those of the primary breast tumor , the left tonsillar tumor was diagnosed as a metastasis of the primary phyllodes tumor . histopathology analysis of the right tonsillar tumor showed growth of spindle cells , necrosis , and atypical nuclei , which differed from the findings for the primary breast phyllodes tumor ( fig . 3 ) . immunostaining showed that the tissue was positive for cytokeratin ae1/ae3 , mnf116 , and cam5.2 . in situ the pathological features of the resected right tonsil were similar to those of undifferentiated carcinoma of the oropharynx . no recurrence of the tonsillar tumors or deterioration of the lung lesion had been observed , but the breast tumor regrew . the central venous catheter became infected with methicillin - resistant staphylococcus aureus during chemotherapy , and the chemotherapy was stopped . phyllodes tumor is an uncommon breast neoplasm that accounts for less than 1.0% of all breast tumors and has the ability to recur and metastasize . phyllodes tumor is graded as benign , borderline , or malignant according to a set of histological data including stromal cellularity , stromal cell atypia , mitotic activity , stromal overgrowth , necrosis , and whether the margin is rounded or infiltrative and shows malignant heterologous elements . the overall incidence of metastasis of phyllodes tumor is 312% , most commonly to the lung . the treatment of choice is excision with a 10-mm margin , although malignant lesions require mastectomy . however , mastectomy is not effective in preventing metastatic disease , and the optimal treatment of metastatic disease has not been established . first , to our knowledge , this is the first reported case of a phyllodes tumor metastasizing to the tonsil . a review of the literature found several reports of phyllodes tumors metastasizing to the head and neck region , including the right ramus , posterior right maxilla , left mandibular posterior quadrant , and left angle and ramus of the mandible . other cases involved gingival metastasis and metastasis of the temporomandibular region , parotid grand , thyroid adenoma . second , this is the first reported case of secondary primary right tonsillar tumor which was developed in the patient with a metastatic left tonsillar tumor . the clinical course suggested that the right tonsillar tumor should be a metastasis of a phyllodes tumor . however , the right tonsillar tumor was diagnosed as undifferentiated carcinoma because the histopathology clearly differed from those of the left tonsillar tumor . secondary neoplasms occurring in cases of phyllodes tumor were reported in one paper . in that report , eight tumors were diagnosed in 6/32 patients as secondary tumors of duodenal cancer , cervical cancer , laryngeal cancer , alveolar cell adenocarcinoma , metastatic colon cancer , astrocytoma , esophageal cancer , and lung adenocarcinoma . another hypothesis is anaplastic transformation of phyllodes tumor ( i.e. , stromal elements may have changed to epithelial elements ) . breast tumor metastasis to the tonsil is rare but it should be considered as a possible diagnosis . we report a case of phyllodes tumor metastasis to the left tonsil which developed undifferentiated carcinoma in the other side of tonsil later . breast tumor metastasis to the tonsil is rare but it should be considered as a possible diagnosis . written informed consent was obtained from the patient for publication of this case report and accompanying images . a copy of the written consent is available for review by the editor - in - chief of this journal on request .
introductionbreast tumor metastasis to the tonsil is extremely rare.presentation of casea 54-year - old woman underwent resection of a breast malignant phyllodes tumor and later presented with metastasis to the lung and the left tonsil . 
 she underwent left lower lobectomy and resection of the left tonsillar tumor . 
 she subsequently developed undifferentiated carcinoma of the right tonsil . 
 she underwent resection of the right tonsillar tumor and chemotherapy was started . 
 the central venous catheter became infected with methicillin - resistant staphylococcus aureus . 
 finally , she died.discussionto the best of our knowledge , this is the first reported case of a phyllodes tumor metastasizing to the tonsil . 
 furthermore , morphological and immunohistochemical study revealed that the right tonsillar tumor was irrelevant to the phyllodes tumors.conclusionwe report a case of phyllodes tumor metastasis to the left tonsil which developed undifferentiated carcinoma in the other side of tonsil later . 
 breast tumor metastasis to the tonsil is rare but it should be considered as a possible diagnosis .