1/61. Malignant transformation of an ovarian mature cystic teratoma presenting as a rectal mass.BACKGROUND: Squamous cell carcinoma arising from malignant degeneration of a mature cystic teratoma is rare with a reported incidence of approximately 1-3%. The most common presenting symptoms are lower abdominal pain and increasing abdominal girth of several months' duration. Approximately 50% of the patients present with FIGO stage I while 35-38% present with stage III diseases. CASE: The case described herein represents an unusual presentation and initial diagnostic dilemma of locally aggressive squamous cell carcinoma arising in an ovarian dermoid cyst, with invasion into the distal rectum and anal canal causing rectal bleeding similar to the presentation of anal squamous cell carcinoma. Despite aggressive surgical management with posterior exenteration and optimal tumor debulking followed by 5040-cGy pelvic radiation utilizing 25-MV photons, the patient developed pelvic recurrence at the vaginal cuff 6 weeks after completion of her adjuvant radiotherapy. She subsequently failed cis-platinum single-agent chemotherapy and died 9 months after her initial surgery and diagnosis. CONCLUSION: Squamous cell carcinoma in the anal canal, diagnosed by colonoscopy or proctoscopy, could be an unusual presentation of that arising from malignant degeneration of an ovarian dermoid cyst. This tumor may behave in a locally aggressive manner and be resistant to pelvic radiation or single-agent chemotherapy of cis-platinum. The current experience of adjuvant treatment after comprehensive staging and cytoreductive surgery reported in the world literature is limited, and the optimal management of the malignancy remains unclear.- - - - - - - - - - ranking = 1keywords = lower (Clic here for more details about this article) |
2/61. Well-differentiated intraosseous osteosarcoma of the jaws: experience of two cases from the Instituto Nacional de Cancerologia, mexico.Osteosarcomas of the jaws represent less than 10% of all osteosarcomas, and most of them are high-grade neoplasms. Prognostic factors in overall survival include tumor size, location and histologic grade. Examples of well-differentiated (low-grade) intraosseous osteosarcomas of the jaws (WDIOJ) have been rarely reported. This article presents two cases of this unusual lesion, one of which was located in the maxilla of a 17-year-old man and the other developed in the mandible of a 37-year-old woman. CT scan was necessary to detect the small foci of penetration into the thinned cortical bone and the reactive periosteal bone formation, which are important findings to establish the correct diagnosis of WDIOJ and help to exclude other benign intraosseous lesions that may be very similar histologically, such as fibrous dysplasia, ossifying and desmoplastic fibromas. In spite of tumor size (mean 5.2 cm), their well-demarcated borders allowed complete removal of both tumors. There is no evidence of tumoral activity in any of our patients after follow-up periods of 15 months and 5 years. Wide excision seems to be the treatment of choice for this subgroup of osteosarcomas.- - - - - - - - - - ranking = 176.3850315149keywords = mandible, jaw (Clic here for more details about this article) |
3/61. Malignant proliferating trichilemmal tumour: a case report.An 86-year-old man presented with a painless, pea-sized growth over the left angle of his jaw, which had been gradually enlarging over two years. A clinical diagnosis of pilar cyst was made. Histopathological examination of the mass revealed a malignant proliferating trichilemmal tumour. During follow-up 4 months later, a palpable small upper jugular lymph node was noted at the left side of the neck. biopsy revealed a metastatic malignant trichilemmal tumour. This case illustrates a rare malignant tumour which is a challenge to clinical diagnosis.- - - - - - - - - - ranking = 17.115473431491keywords = jaw (Clic here for more details about this article) |
4/61. Ameloblastic carcinoma ex ameloblastoma of the mandible with malignancy-associated hypercalcemia.ameloblastoma is a rare, locally destructive, benign neoplasm of the jawbones, which arises from epithelium derived from the epithelial components of the developing tooth. Ameloblastic carcinoma is the term used to designate any ameloblastoma in which there is histologic evidence of malignancy in the primary tumor, regardless of whether it has metastasized. Most ameloblastic carcinomas are presumed to have arisen de novo, with few cases of malignant transformation of ameloblastoma being apparent. hypercalcemia is the most common metabolic complication of malignancy. Although malignancy-associated hypercalcemia is often reported in association with other malignancies, it is exceedingly unusual in association with ameloblastoma, malignant ameloblastoma, or ameloblastic carcinoma. We describe a patient with multiple recurrences of ameloblastoma, with subsequent malignant transformation presenting with malignancy-associated hypercalcemia.- - - - - - - - - - ranking = 311.88423713532keywords = mandible, jaw (Clic here for more details about this article) |
5/61. Proliferating trichilemmal tumors: CT and MR imaging findings in two cases, one with malignant transformation.We report the imaging findings in two patients with proliferating trichilemmal tumors. In the first patient, the tumor arose on the lower lip, a very unusual location for this type of tumor, and showed malignant transformation with metastasis to a regional lymph node. It was seen as a poorly marginated soft-tissue mass with isointense signal on T1-weighted MR images and hyperintense signal on T2-weighted images. Large areas of high signal intensity caused by necrosis were also found within the tumor on T2-weighted images. After i.v. administration of contrast material, the mass showed significant enhancement, with considerable portions remaining unenhanced. In the second patient, the tumor originated from a preexisting trichilemmal cyst and occurred in the hair-bearing area of the posterior part of the neck. CT scans showed a well-encapsulated cystic mass that contained multiple speckled calcifications in a wall of variable thickness. There were several foci of smooth soft-tissue elevations from the inner wall of the mass, which corresponded histologically to proliferating portions of trichilemmal cyst.- - - - - - - - - - ranking = 1keywords = lower (Clic here for more details about this article) |
6/61. adenocarcinoma complicating Barrett's esophagus: an analysis of cell proliferation.In japan, cases of Barrett's esophagus with concurrent adenocarcinoma are relatively rare. We report herein a case of long-segment Barrett's esophagus-associated adenocarcinoma in a 72-year-old Japanese man. The surgical specimen showed that an ulcerating tumor, measuring 5.5 x 3.9 cm, was present in the lower esophagus adjacent to the esophagogastric junction, the background lower esophagus having an erythematous appearance. Histologically, the ulcerating tumor was a well-to-moderately differentiated tubular adenocarcinoma, with a small area of signet ring cell carcinoma invading the adventitia. In addition, the esophageal epithelium was replaced by columnar epithelium (9.5 cm in length) with multifocal dysplastic changes. Immunohistochemically, the number of Ki-67-positive cells gradually increased, moving from the normal gastric mucosa (mean Ki-67 labeling index [mKLI], 2.6%) through Barrett's epithelium (mKLI, 12.9%), low-grade dysplasia (mKLI, 16.9%), and high-grade dysplasia (mKLI. 23.7%) to invasive carcinoma, in that order, with labeling higher in the invasive tubular adenocarcinoma elements (mKLI, 40.5%) than in areas of signet ring cell carcinoma (mKLI, 20.4%). Findings in our patient suggest that increased cellular proliferation plays an integral part, in the progression of Barrett's metaplasia to adenocarcinoma. The collection of further cases for analysis will be necessary to confirm this hypothesis.- - - - - - - - - - ranking = 2keywords = lower (Clic here for more details about this article) |
7/61. Calcifying epithelial odontogenic (Pindborg) tumor with malignant transformation and metastatic spread.BACKGROUND: Pindborg tumors (calcifying epithelial odontogenic tumors) are uncommon neoplasms of odontogenic origin most often located in the posterior mandible. First described in detail in 1955 by Pindborg, these tumors are considered benign but can be locally aggressive in nature, with recurrence rates of 10% to 15% reported. The malignant form of this tumor is exceedingly rare. methods: We describe the case of a 64-year-old woman initially treated for a painful infected left mandibular third molar. The patient underwent extraction of the tooth and excision of an associated soft tissue component. Subsequent histologic review identified a Pindborg tumor of the left posterior mandible. RESULTS: After initial excision, this tumor recurred twice, with the recurrences exhibiting a progression to a malignant Pindborg tumor (odontogenic carcinoma) with vascular invasion and spread to a cervical lymph node. Further treatment involved radical surgery and adjuvant radiotherapy. At last review 12 months after treatment, the patient was disease free. CONCLUSIONS: This article describes only the second case of odontogenic carcinoma. The transformation from benign to malignant histologic findings has not previously been documented in this tumor. The salient clinical features of this case are presented along with supportive pathologic and radiologic evidence.- - - - - - - - - - ranking = 147.38438185191keywords = mandible (Clic here for more details about this article) |
8/61. Central mucoepidermoid carcinoma--a case report.The mucoepidermoid carcinoma (MEC) account for approximately 6-8 Percent of all salivary gland tumors. Central mucoepidermoid carcinoma of the jaws is rare. Following is a case report of central mucoepidermoid carcinoma which involves the ramus of the mandible. Origin of the central mucoepidermoid carcinoma is discussed.- - - - - - - - - - ranking = 90.807664357448keywords = mandible, jaw (Clic here for more details about this article) |
9/61. Minute lung carcinoma associated with focal honeycombed lesion.We report a case of minute lung carcinoma that developed in a focal honeycombed lesion in the right lung. A 70-year-old man presented hemosputum, and a cytological examination result was at class IV. A right lower lobectomy of the lung was performed. Microscopically, the thickened alveolar wall revealed tumor cells indicating a minute carcinoma, and showed squamous hyperplasia, metaplasia, and dysplasia, with the carcinoma in the distal airway epithelium. This peripheral lung carcinoma in a focal honeycombed lesion demonstrated the various stages of multistep carcinogenesis, which is recognized in hilar type squamous cell carcinoma. To date, the association between a honeycombed lesion and lung cancer has been poorly described. Here we have presented clear evidence of the association of this carcinoma with the honeycombed lesion.- - - - - - - - - - ranking = 1keywords = lower (Clic here for more details about this article) |
10/61. Chromophobe renal cell carcinoma with osteosarcoma-like differentiation.Sarcomatoid differentiation in renal cell carcinoma is thought to be the result of the dedifferentiation of the parent tumor, and it can be found in the chromophobe renal cell carcinoma just as other subtypes. We report a case of chromophobe renal cell carcinoma, which showed osteosarcoma-like differentiation. This is the first known case ever to be clearly identified as such. The patient was a 74-year-old man, and the CT scan revealed a huge retroperitoneal mass, which protruded from the lower half of the kidney and directly invaded the colon. Intraabdominal dissemination and metastases to the liver and lungs were also found. The resected tumor histologically showed sarcoma-like spindle cell proliferation and partly produced massive osteoid, which simulated the osteosarcoma. In addition, a typical histology of chromophobe renal cell carcinoma was found in part of the tumor. Immunohistochemically, spindle cells were reactive for epithelial membrane antigen, cytokeratin, and vimentin. The cell nests that were labeled by epithelial membrane antigen and cytokeratin were also found in the osteosarcoma-like area. We think that these phenomena were the result of "dedifferentiation" and metaplasia of the chromophobe renal cell carcinoma.- - - - - - - - - - ranking = 1keywords = lower (Clic here for more details about this article) |
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