1/51. Simultaneous phenotypically distinct but clonally identical mucosa-associated lymphoid tissue and follicular lymphoma in a patient with sjogren's syndrome.A 44-year-old woman with a 12-year history of sjogren's syndrome (SS) developed a low-grade mucosa-associated lymphoid tissue (MALT) lymphoma in the parotid gland. Two years later, she presented with generalized lymphadenopathy and hepatosplenomegaly and a follicular lymphoma was diagnosed. To investigate the relationship of the two histologically distinct lymphomas, we re-examined their histology and immunophenotype and studied the lymphomatous tissue from the parotid, cervical lymph node, and spleen using molecular genetic methods. Histologic and immunophenotypic studies confirmed the previous diagnoses and also identified a previously unnoticed focus of follicular lymphoma in the second parotid gland biopsy. polymerase chain reaction (PCR) amplification of the rearranged Ig heavy-chain gene showed the same sized dominant product in the MALT lymphoma and the follicular lymphoma. Similarly, PCR analysis of the t(14:18) translocation yielded an identical sized band from both MALT and follicular lymphoma. Cloning and sequencing of the Ig PCR products showed an identical CDR3 sequence from each lesion, indicating a common clonal lineage. The follicular lymphoma of the parotid gland lymph node and the follicular lymphoma of the spleen showed an identical mutation signature to that of the salivary gland MALT lymphoma. We propose that follicular lymphoma in the parotid gland lymph node may have resulted from colonization of lymphoid follicles by MALT lymphoma cells, following which the tumor cells were induced to express a follicular lymphoma phenotype, due to Bcl-2 overexpression caused by t(14;18), leading to a change in clinical behavior resulting in rapid widespread dissemination of disease. These observations suggest that the distinct phenotypes of low-grade B-cell lymphomas may be the consequence of interplay between genetic and local microenvironmental factors.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
2/51. Pleomorphic salivary adenoma in an adolescent.This case study illustrates an unusual condition in childhood, pleomorphic salivary adenoma in a 12-year-old. The management, pathology and treatment are discussed with emphasis on the practitioner to be vigilant for rare conditions. A review of the literature on childhood salivary tumours illustrates the rare nature of this pathology.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
3/51. Nodular fasciitis presenting as a parotid tumour after face lifting.Nodular fasciitis, a benign, pseudosarcomatous proliferative lesion of the soft tissue, is frequently misinterpreted as a sarcoma, both clinically and microscopically. Lesions associated with the parotid gland have been very rarely reported. We report a case of nodular fasciitis mimicking a parotid tumour after a facelift. We performed histological and immunohistochemical study and CT scan for it is difficult to make a differential diagnosis. We confirmed the final diagnosis as intraparotid nodular fasciitis. Superficial parotidectomy was performed because of initial pathological misdiagnosis reported as a dermatofibroma. The subsequent diagnosis was confirmed to be nodular fasciitis on the basis of immunohistochemical study. There was no recurrence after follow-up to 18 months. Proper diagnosis of nodular fasciitis in the parotid region and early recognition of its benign nature are necessary to differentiate it from other various benign and malignant tumours of the parotid gland.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
4/51. carcinosarcoma of the parotid gland: ultrasound and computed tomography findings.carcinosarcoma is a rare tumour of the salivary gland. The ultrasound and CT appearances of a rapidly enlarging carcinosarcoma in the parotid are described. Both modalities revealed a 4-cm tumour with relatively benign features and no evidence of lymphadenopathy. Ultrasound showed a well-defined mass of homogeneous low echogenicity and posterior acoustic enhancement. Computed tomography showed a parotid mass of homogeneous attenuation similar to muscle, and homogeneous enhancement following contrast. The clue to the malignant nature of the lesion was a short indistinct superficial margin with tumour extension into the adjacent subcutaneous tissues.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
5/51. Metastasizing mixed tumor of the parotid: initial presentation as a solitary kidney tumor and ultimate carcinomatous transformation at the primary site.Benign mixed tumors of the salivary glands are generally regarded as indolent and harmless neoplasms. A subset of benign mixed tumors, however, can undergo carcinomatous transformation (that is, carcinoma ex-mixed tumor). Even more rarely, a mixed tumor that is seemingly benign at the microscopic level will metastasize like a true carcinoma (that is, metastasizing mixed tumor [MZMT]). Despite the benign appearance of the metastatic implants, there is usually little doubt regarding their true nature and origin. patients invariably have had a mixed tumor removed from the parotid or some other salivary gland, and metastatic spread is usually preceded by multiple episodes of local tumor recurrence. We report a case of MZMT that presented as a solitary kidney mass. In the absence of a previous or concurrent salivary gland tumor, its metastatic nature was not appreciated and it was regarded as an unusual but benign kidney adenoma. One year after removal of the kidney mass, the patient presented with signs and symptoms of an aggressive parotid tumor. Pathologic examination of the tumor in the parotid demonstrated a high-grade carcinoma arising from a mixed tumor. This case underscores the importance of considering MZMT when a seemingly benign mixed tumor is encountered at a nonsalivary site, even in patients without a supportive history. Failure to do so may cause an unnecessary delay in primary tumor diagnosis and management, allow the primary tumor to progress toward a more malignant phenotype, and deny the patient a high expectation for a complete cure.- - - - - - - - - - ranking = 2keywords = nature (Clic here for more details about this article) |
6/51. Primary T cell lymphoma of salivary gland: a report of a case and review of the literature.lymphoma of the salivary gland accounts for 5% of cases of extranodal lymphoma and 10% of malignant salivary gland tumours. Most primary salivary gland lymphomas are B marginal zone lymphomas arising on a background of sialadenitis associated with autoimmune disorders such as Sjorgen's syndrome. Primary T cell lymphoma of the salivary gland is rare. This report describes a case of primary T cell lymphoma arising in the parotid gland of an elderly white man, which was notable for its striking resemblance to a B cell extranodal marginal zone lymphoma. immunohistochemistry and gene rearrangement studies confirmed the clonal T cell nature of the tumour. There was no molecular evidence of Epstein-Barr virus (EBV) infection of neoplastic or surroundings cells. Only 14 cases of primary T cell lymphoma of the salivary glands have been recorded in the literature, most being from the Orient and having extremely variable prognosis. Those with a T/natural killer cell phenotype are associated with EBV infection. This case highlights the fact that T cell lymphoma in the salivary gland can mimic closely the morphological features of B cell extranodal marginal zone lymphoma.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
7/51. Keratocystoma of the parotid gland: a report of two cases of an unusual pathologic entity.Benign salivary gland tumors composed of purely squamous cells are quite unusual and are not included in the world health organization classification. We have seen two benign parotid gland tumors characterized by multicystic spaces with stratified squamous linings and focal solid epithelial nests. Seifert et al. recently described such a case as a choristoma; we, however, herein propose a new designation, keratocystoma, for this unique tumor group, because of its distinctive histological features. These tumors occurred in men aged 18 and 38 years with enlarging parotid gland tumors. Both had largely similar gross and histological features, with some variations. The epithelium lining of the cysts showed apparent keratinization through a parakeratotic or orthokeratotic pathway without forming a granular cell layer. Stratification of the epithelium was always regularly oriented from the outer basal to the inner keratotic cell layer. Focally, the outer layer had bud-like protrusions. In some areas, solid squamous cell islands surrounded by basement membrane were enclosed within the collagenous stroma. These cystic and solid structures were randomly distributed, showing no definite lobular architecture. All of the tumor cells had uniform, bland nuclei and abundant eosinophilic cytoplasm. Scattered mitotic figures were observed, limited to the outer epithelial layer, and showed no abnormal patterns. Transformation from the parotid ductal epithelium to the tumor cells is evident. Foci of foreign-body reactions against keratin materials were present. Immunoreactivities for cytokeratins reconfirmed the nature of squamous differentiation of the tumor cells. Ki-67-positive cells were confined along the outer basal layer of the tumor epithelium. Tests for alpha-smooth muscle actin and S-100 protein were completely negative. Both patients had no evidence of recurrence 3 and 2 years after subtotal parotidectomy, respectively, without any additional therapy. We believe that this lesion represents a benign cystic neoplasm rather than a malignant tumor or pseudoneoplastic metaplastic condition. It is important to recognize that this peculiar benign tumor does originate from the salivary gland.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
8/51. Intraparotid facial nerve neurofibromas.OBJECTIVES: To provide an awareness of intraparotid facial nerve neurofibroma as a cause of parotid masses and to describe their characteristics and management considerations. STUDY DESIGN: Case report with literature review. methods: The medical records of three patients with intraparotid facial nerve neurofibromas are reviewed, and data concerning the patient's presentations, treatment, and disease course are presented with a review of the world's literature on intraparotid facial nerve neurofibromas. CONCLUSIONS: Tumors arising from the extratemporal course of the facial nerve are quite rare. The tumors arise from schwann cells and include the schwannoma and the neurofibroma. The overwhelming benign nature of these lesions necessitates a conservative course of treatment. Histological diagnosis should be followed by a limited tumor excision with emphasis on retaining normal facial nerve function. Malignant lesions require wide excision with facial nerve grafting or facial nerve reanimation.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
9/51. Cutaneous metastasis from adenoid cystic carcinoma of the parotid gland.BACKGROUND: Cutaneous metastasis from adenoid cystic carcinoma of the salivary gland is very rare. OBJECTIVE: To present an unusual case of cutaneous metastasis from adenoid cystic carcinoma of the right parotid gland. methods: A 63-year-old woman with multiple subcutaneous nodules on the abdomen and a gradually enlarged mass over the right parotid area was examined. A skin biopsy was taken from one of the abdominal nodules. RESULT: skin biopsy demonstrated the characteristic histopathologic features of metastatic adenoid cystic carcinoma. A subsequent computerized tomography of the head and neck revealed a huge soft tissue mass involving the right parotid gland. Computerized tomography of the chest revealed extensive nodular pleural thickening, and pleural biopsy also showed typical histopathologic features of metastatic adenoid cystic carcinoma. All of these results are consistent with the diagnosis of an adenoid cystic carcinoma of the right parotid gland with disseminated metastases. CONCLUSION: We report a rare case of cutaneous metastasis from adenoid cystic carcinoma of the right parotid gland. The presentation of cutaneous metastasis is often nonspecific and may mimic benign lesions. Subcutaneous nodules that are rapidly developing or eruptive, are rapidly growing and have stony hardness in nature, have pain or tenderness, and have nonhealing ulceration remind us of the possibility of cutaneous metastases. Dermatologists and dermatologic surgeons should keep the diagnosis of cutaneous metastasis in mind and always perform skin biopsy when encountering these lesions.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
10/51. Sebaceous lymphadenocarcinoma of salivary glands.Primary sebaceous neoplasms of the salivary glands are extremely rare occurrences; furthermore, sebaceous lymphadenocarcinoma has only been reported in three patients. We report a case of sebaceous lymphadenocarcinoma arising in a lymphadenoma of the parotid gland. The patient was a 55-year-old man who presented with a parotid mass of 3 years' duration. Histologically, the lesion consisted of a sebaceous lymphadenoma with transition to a sebaceous carcinoma. The cytologic touch-preparation at the time of frozen section showed clusters of benign sebaceous cells in a rich lymphocytic background together with tridimensional clusters of malignant epithelial cells, strongly raising the suspicion of a malignant neoplasm arising in a benign sebaceous lesion. Malignant transformation of the sebaceous lymphadenoma, although rare, should be considered in enlarging, locally invasive parotid lesions, considering that clinical behavior and prognosis will be determined by the nature of the malignant component.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
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