11/56. Malignant transformation in congenital sebaceous naevi in childhood.Sebaceous naevi are uncommon congenital skin lesions with a well-recognised potential for neoplastic change. They should be considered premalignant lesions as malignant degeneration, most commonly basal cell carcinoma and squamous cell carcinoma, occurs with a lifetime risk of between 5% and 22%. This incidence is equal to that of actinic keratosis and exceeds that of oral leukoplakia. Such change, however, is rare before puberty. Basal cell carcinoma may develop in children with naevoid basal cell carcinoma syndrome, xeroderma pigmentosum and rarely de novo but sebaceous naevus is the only solitary lesion in childhood associated with the development of basal cell carcinoma. We present two cases of malignant transformation in a congenital sebaceous naevus occurring in childhood and review the literature and discuss the evidence upon which to base management guidelines.- - - - - - - - - - ranking = 1keywords = naevus (Clic here for more details about this article) |
12/56. 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 = 0.96598742804704keywords = spindle cell, spindle (Clic here for more details about this article) |
13/56. leiomyosarcoma showing partial synthetic-phase differentiation.An unusual leiomyosarcoma in the thigh of a 53-year-old woman is described. Tumor cells were spindled and positive for muscle immuno-markers. Some cells exhibited typical smooth-muscle ultrastructure--abundant myofilaments, focal densities, attachment plaques, plasmalemmal caveolae, and lamina. Others had fewer myofilaments and prominent rough endoplasmic reticulum. These features indicated a variable phenotype that included synthetic-phase (matrigenic) differentiation. Synthetic-phase cells were distinguished from myofibroblasts by typical smooth-muscle surface features in the absence of fibronexus junctions. In a subset of cells myofilaments were absent, but structures resembling solitary focal densities were identified. These are discussed as possible indicators of a primitive level of smooth-muscle differentiation.- - - - - - - - - - ranking = 0.12780852805853keywords = spindle (Clic here for more details about this article) |
14/56. carcinosarcoma of the esophagus characterized by myoepithelial and ductal differentiations.We report a case of carcinosarcoma of the esophagus characterized by ductal and myoepithelial differentiation. A 61-year-old man was operated on for a polypoid tumor of the distal esophagus. Histologically, this tumor was composed of ductal structures and sarcomatous spindle cells surrounding the ducts at the central area of the tumor. The tumor was also composed of squamous cell and basaloid carcinoma in the periphery. Immunohistochemically, a few spindle cells surrounding the ductal structures showed immunopositivity for alpha-smooth muscle actin and S-100 protein. Electron microscopy revealed that the spindle cells had tonofilament and pinocytic vesicles in the cytoplasm, and basal lamina adjacent to the cytoplasmic membrane. Both of the results strongly supported the suggestion that the spindle cells may be myoepithelial cells. Basaloid carcinoma showed a gradual transition to chondrosarcomatous cells producing the matrix, which had both immunopositivities for S-100 protein and cytokeratin. Therefore, chondrosarcomatous cells may be derived from carcinoma cells. The histogenesis of this tumor may be associated with a totipotent stem cell of esophageal mucosa, which has the potential to differentiate into squamous cells, ductal cells or myoepithelial cells.- - - - - - - - - - ranking = 1.9319748560941keywords = spindle cell, spindle (Clic here for more details about this article) |
15/56. Pseudo-tumoral proliferative nodule in a giant congenital naevus.OBJECTIVE: To discuss the characteristics of proliferative nodules in giant congenital naevi. methods: We report the case of a newborn referred for staged curettage of a giant congenital naevus. A nodule was discovered on his left flank. It was excised for analysis during the first treatment session during the second week of life. RESULTS: The nodule was soft and looked like a lipoma. On optical microscopy however, there was a high cellular density and a high number of mitoses. Although the genetic analysis for melanoma antigens was reassuring, a firm nodule recurred a few days later. A second excision was performed at the fourth week. Surprisingly, on optical microscopy, the cellular density was much lower and there were no more atypias or mitoses; many neurotization foci were present. The natural history changed to spontaneous regression of the cellular activity. The diagnosis of proliferative nodule was made. CONCLUSION: Proliferative nodules in giant congenital naevi have specific clinical and histological characteristics. These should however be put into perspective. As demonstrated in this case, there can be an initial high mitotic activity within the nodule but this should not lead to the misdiagnosis of malignant melanoma. The spontaneous regression of cellular activity will allow the correct diagnosis to be made.- - - - - - - - - - ranking = 2.5keywords = naevus (Clic here for more details about this article) |
16/56. Monophasic sarcomatoid carcinoma of the scalp: a case mimicking inflammatory myofibroblastic tumor and a review of cutaneous spindle cell tumors with myofibroblastic differentiation.BACKGROUND: The evaluation of malignant cutaneous spindle cell tumors is challenged by a diagnostic differential that comprises neoplasms of diverse histogenesis, and a broad immunohistochemical panel may confound the diagnosis when the results suggest multiple lines of differentiation, such as with a combined myofibroblastic and epithelial phenotype. methods: We report the case of a solitary scalp nodule that quickly became locally metastatic. A comprehensive panel of immunohistochemistry markers and electron microscopy was evaluated to determine the differentiation of the spindle cells. RESULTS: The tumor, consisting of wavy and slender spindle cells with predominantly bland nuclei, showed immunoreactivity to vimentin, smooth muscle actin, and muscle-specific actin. AE1/AE3, CK5/6, and MNF-116 antibodies were weakly positive in rare cells. However, 34betaE12 showed diffuse positivity in the spindle cell population, thus supporting the diagnosis of a sarcomatoid carcinoma with myofibroblastic differentiation. CONCLUSIONS: The use of 34betaE12 is essential for the evaluation of myofibroblastic spindle cell tumors with rare cytokeratin reactivity. However, even with immunohistochemical and electron microscopic studies, the diagnosis of spindle cell tumors can be confounded by the multiplicity of nosologic equivalents, such as carcinosarcoma, spindle cell carcinoma, and metaplastic carcinoma. The nomenclature of these spindle cell tumors is discussed.- - - - - - - - - - ranking = 5.7959245682822keywords = spindle cell, spindle (Clic here for more details about this article) |
17/56. Dedifferentiated malignant myoepithelioma of the parotid gland.Dedifferentiated salivary gland tumor is a rare, recently recognized tumor type. A case of dedifferentiated malignant myoepithelioma in a 59-year-old man who presented with a painful mass in the left preauricular region is reported. Histologically, two distinct neoplastic cell populations were observed in the same tumor mass. The first population was composed of solid nests of polygonal eosinophilic or glycogen-rich clear cells showing neoplastic myoepithelial immunocytological features, such as positivity for cytokeratins, vimentin, S-100 protein (S-100), alpha-smooth muscle actin (SMA) and glial fibrillary acidic protein (GFAP). A multinodular growth pattern, necrosis and occasional mitotic figures suggested malignancy. This population was diagnosed as low-grade malignant myoepithelioma. The second population infiltrated diffusely into the parotid gland and facial nerves. It consisted of polygonal or short spindle cells with obvious pleomorphism and atypical mitoses. The tumor cells were positive for vimentin and cytokeratins, and showed an accumulation of p53 and cyclin d1. S-100 protein, SMA and GFAP were negative. This population was regarded as undifferentiated carcinoma. A final diagnosis of dedifferentiated malignant myoepithelioma was made. This seems to be the first published case of dedifferentiation in malignant myoepithelioma. Because any tumor type can undergo dedifferentiation with accumulation of additional genetic changes, complete sampling should be the standard approach to all salivary gland tumors in order to avoid missing a dedifferentiation component.- - - - - - - - - - ranking = 0.48299371402352keywords = spindle cell, spindle (Clic here for more details about this article) |
18/56. Chromophobe renal cell carcinoma with sarcomatoid transformation.We present a rare case of a chromophobe renal cell carcinoma that progressed to a high-grade spindle cell sarcoma. The tumor affected a 50-year-old man who had presented with right upper quadrant discomfort and hematuria and subsequently underwent a right radical nephrectomy. Microscopically, the tumor was composed of two distinct components, a chromophobe renal cell carcinoma and a sarcomatoid component. The sarcomatoid component had exhibited aggressive behavior by spreading to a regional lymph node. This case report shows that chromophobe carcinoma can develop a sarcomatoid transformation with a high propensity for invasive growth and metastasis.- - - - - - - - - - ranking = 0.48299371402352keywords = spindle cell, spindle (Clic here for more details about this article) |
19/56. Metanephric adenoma and papillary carcinoma with sarcomatoid dedifferentiation of kidney. A case report.We present the case of a 74-year-old Caucasian male with an expansive process of the left kidney. No clinical and laboratory signs of polycytemia or hypertension were present. Microscopically, the spherical main tumor mass was composed of small basophilic cells arranged in longitudinal branching tubules typical of metanephric adenoma (MA). Another component, different from MA, was formed by a tumor in a papillary and tubopapillary arrangement. This component was diagnostic of grade 3 papillary renal cell carcinoma. The third component, which was merging with the papillary one, was composed of sarcomatoid, spindle cell carcinoma with prominent nuclear polymorphism and a high number of mitotic figures, including atypical mitoses. The sarcomatoid component filled the entire cortico-medullary space and infiltrated the surrounding non-neoplastic renal tissue, including the renal pelvis. Areas of necroses, hemorrhages, and mitotic figures were frequent. No structures of Wilm's tumor were seen in our case. One year after the excision, the patient is without recurrence and metastasis. The existence of the above mentioned tumor supports the hypothesis that metanephric adenomas and papillary renal cell carcinomas are interrelated lesions.- - - - - - - - - - ranking = 0.48299371402352keywords = spindle cell, spindle (Clic here for more details about this article) |
20/56. Spindle cell transformation of papillary carcinoma: an aggressive entity distinct from anaplastic thyroid carcinoma.Spindle cells are not routinely encountered in the context of thyroid pathology and are most often present in anaplastic thyroid carcinoma, medullary thyroid carcinoma, and benign conditions such as Riedel struma or de Quervain granulomatous thyroiditis. Only a few publications have reported papillary thyroid carcinoma admixed with a prominent spindle cell component. While these tumors are clearly distinct from anaplastic thyroid carcinoma, prognostication as to their oncologic potential is not yet established. We describe a unique case of spindle cell transformation of papillary thyroid carcinoma. The blandness of the spindle cells was so impressive as to dissuade us from a malignant diagnosis on preoperative biopsies. However, this patient unfortunately died shortly after transformation of this papillary thyroid carcinoma. We conclude that this peculiar and rare spindle cell transformation should be regarded as a potentially lethal variant of papillary thyroid carcinoma.- - - - - - - - - - ranking = 1.9319748560941keywords = spindle cell, spindle (Clic here for more details about this article) |
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