131/479. Malignant rhabdoid tumor arising from a pleomorphic adenoma. Malignant transformation of pleomorphic adenomas often occurs in long-standing tumors or tumors with multiple local recurrences. The malignant component is usually a carcinoma. The case reported herein concerns a 60-year-old man who had a malignant rhabdoid tumor arising in a painless parotid mass that remained untreated for 25 years. Malignant rhabdoid tumors are clinically aggressive neoplasms with phenotypic features that resemble rhabdomyomatous differentiation but lack genuine skeletal muscle differentiation. The salient features of rhabdoid tumor cell include large, pleomorphic, and eccentric nucleus and a solitary and prominent intracytoplasmic inclusion that is strongly immunoreactive for vimentin. It is our understanding that this is the first reported case of malignant rhabdoid tumor arising in the parotid gland in the English literature. The pathologic features of our case will be discussed in context with malignant rhabdoid tumors from other parts of the body. ( info) |
132/479. Pigmented pleomorphic adenoma, a novel melanin-pigmented benign salivary gland tumor. This paper reports a pleomorphic adenoma with grossly visible pigmentation resulting in the macroscopic appearance of melanotic lesion in a 33-year-old Japanese male. In addition to the characteristic histopathological features of a benign pleomorphic adenoma, variously formed and -sized cells, many of which were considered to be melanocytes, containing melanin pigment in their cytoplasm, were distributed in the epithelial component. In addition, melanin pigment was deposited in tumor cells of duct structures. Furthermore, condensed secretory substances with marked pigmentation were frequently seen in the tubular lumina. Perusal of the English language literature revealed only two cases of parenchymal pigmentation of salivary gland tumors: both were mucoepidermoid carcinoma. The possible histogenesis of melanocytes in the salivary gland lesions is discussed, though no firm conclusion could be drawn. ( info) |
| We present a unique case characterized by true coexistence of synovial chondromatosis (SC) of the temporomandibular joint (TMJ) with a salivary gland tumor, specifically pleomorphic adenoma, of the ipsilateral parotid gland. The possibility that the condition was the result of a single pathologic entity, ie, SC with extracapsular involvement or pleomorphic adenoma affecting the TMJ, received strong consideration. Nonetheless, careful assessment of the clinical, radiographic, MRI, and surgical findings strongly suggested the synchronous occurrence of 2 separate pathologic processes, despite their close proximity. Further, histopathologic examination confirmed the presence of both SC of the TMJ and pleomorphic adenoma of the superficial lobe of the ipsilateral parotid gland. Previous reports have pointed out the possibility of misdiagnosing extracapsular spread of SC as a salivary gland tumor. Vice versa, it has been noted that parotid gland tumors, especially malignant, may cause TMJ symptoms similar to those of SC. However, to the best of our knowledge, this is the first time that true synchronous occurrence of ipsilateral SC and pleomorphic adenoma, or parotid tumor of any kind, is reported. ( info) |
134/479. Pleomorphic adenoma of the lateral side of the tongue. Pleomorphic adenoma is histopathologically the commonest tumor found in the major salivary glands. Pleomorphic adenoma originating from the tongue is very rare: only 26 cases have been reported in the world literature since 1960, only 2 of which originated from Ebner's gland. Herein we report the case of a 54-year-old female with pleomorphic adenoma of the tongue. The tumor was in contact with the molars. A partial glossectomy was performed with a surgical margin, as the preoperative pathological finding in the tissue specimen taken from the tumor was epithelial hyperplasia. The postoperative pathological diagnosis was pleomorphic adenoma with hyperplasia. It is unclear whether the teeth being in contact with the tumor caused tumorigenesis in this case. This case suggests that pleomorphic adenoma of the tongue originating from Ebner's gland should be considered in the differential diagnosis of lesions of the tongue. ( info) |
135/479. Malignant chondroid syringoma with bone invasion: a case report and review of the literature. We describe a 27-year-old Japanese female with a recurrent nodule on the left big toe and local bone invasion. Histopathologically, the tumor consisted of nests of atypical cells with few mitotic cells, which partly formed gland-like structures. Areas of myxoid degeneration, positive for alcian blue staining and that did not stain after they were digested with hyaluronidase, were prominent in the matrix among tumor cells. Positive staining was noted in tumor cells for cytokeratin (AE1 AE3), S-100 protein, neuron specific enolase (NSE), and glial fibrillary acidic protein (GFAP). These findings, especially positive GFAP staining were characteristic and very helpful for the diagnosis of the rare tumor-malignant chondroid syringoma. Based on the previous reports, 39% of cases were found to have metastatic lesions and 22% died of this malignant tumor. There have been no reports reporting effectiveness of chemotherapy and radiotherapy, and an early wide excision with a broad margin may be the most reliable treatment to date. ( info) |
136/479. Metastatic carcinoma with myxoid stroma in the salivary gland: a case report. BACKGROUND: Most epithelial salivary gland tumors with a myxoid stroma are pleomorphic adenomas. Rare metastatic carcinomas have prominent myxoid stroma and therefore can mimic pleomorphic adenomas cytologically. CASE: A 62-year-old man presented with a left canthal tumor. A biopsy and computed tomography revealed an adenocarcinoma of the left ethmoid sinus with medial canthal extension. The patient was treated with tumor resection and chemoradiation. An enlarging, left parotid mass developed that was reported as a pleomorphic adenoma on a fine needle aspirate. However, a parotidectomy showed metastatic adenocarcinoma with a myxoid and fibroblastic stroma in an intraparotid lymph node. CONCLUSION: Before concluding cytologically that a biphasic epithelial/myxoid stromal salivary gland lesion is a pleomorphic adenoma, the patient's previous malignancies should be reviewed, and the smears should be scrutinizedfor the absence of diffuse epithelial atypia and presence of spindle cells transitional between the 2 tissue phases. ( info) |
137/479. Metastasizing mixed tumour of the parotid gland presenting as multiple lung metastases. Metastasis is a feature of malignant neoplasms. Although rare, metastasizing pathologically benign mixed tumour has been reported. This report describes a 33-year-old woman with multiple lung metastases from mixed tumour. A small preauricular mass had been removed 23 years earlier. Six years later, the patient had the same symptom; the recurrent mass was resected. She was not aware of the exact pathological diagnosis of the previous tumours. One of the most common features of metastasizing mixed tumour is recurrence at the primary site. Inadequate resection of the primary tumour is often associated with metastasis. Thus, it is important for the head and neck surgeon to be aware of the concept of pathologically benign metastasizing mixed tumour and the importance of adequate surgical procedure. ( info) |
138/479. Basal cell carcinoma occurring in scar tissue following excision of a parotid gland pleomorphic adenoma. BACKGROUND: A 49-year-old patient presented with a basal cell carcinoma growing on scar tissue left following excision of a parotid gland pleomorphic adenoma. OBJECTIVE: The objective was to determine whether the basal cell carcinoma had resulted from tumor spillage at the time of the pleomorphic adenoma excision. methods: Substantial evidence is presented linking the two tumors. RESULTS: The basal cell carcinoma most likely occurred as the result of tumor spillage at the time of the parotid gland pleomorphic adenoma excision. CONCLUSIONS: Cutaneous connective tissue stroma plays a significant role in determining the differentiation of basal cell carcinomas. ( info) |
139/479. Pleomorphic adenoma of the base of the tongue. We describe a rare case of pleomorphic adenoma involving the base of the tongue and adjacent valleculae. We also discuss the incidence, diagnosis, and treatment of these cases. ( info) |
140/479. Pleomorphic adenoma of the palate. Pleomorphic adenoma, is the most common tumor (50%) of the major and minor salivary glands. Seventy percent of the tumors of the minor salivary glands are pleomorphic adenomas, and the most common intraoral site is the palate, followed by the upper lip and buccal mucosa. Pleomorphic adenoma appears as a painless firm mass and, in most cases, does not cause ulceration of the overlying mucosa. Generally it is mobile, except when it occurs in the hard palate. Intraoral mixed tumors, especially those noted within the palate, lack a well-defined capsule. Lesions of the palate frequently involve periosteum or bone. Approximately 25% of benign mixed tumors undergo malignant transformation. Treatment for the pleomorphic adenoma is radical surgery. Inadequate resection leads to local recurrence. The authors report a palate pleomorphic adenoma in a 67-year-old female patient. ( info) |