1/9. Mixed tumors, myoepitheliomas, and oncocytomas of the soft tissues are likely members of the same family: a clinicopathologic and ultrastructural study.Four diagnostically unusual soft tissue tumors are presented. All lesions were of consistent size and long duration. Histologically, one lesion was analogous to mixed tumors of the usual sites (i.e., salivary glands), one lesion was totally spindled, and the two other lesions both had oncocytic appearances (epithelioid and spindle biphasic pattern in a case, purely epithelioid in the other). Immunohistochemically, the mixed tumor was positive for vimentin, cytokeratins, S-100 protein, and focally for EMA. The purely spindled tumor exhibited immunoreactivity for vimentin, actins, S-100 protein, EMA (focally), and GFAP. The oncocytic biphasic tumor was positive for mitochondrial antigen, vimentin, and actins. The purely epithelioid oncocytic neoplasm was immunoreactive only for mitochondrial antigen and vimentin. Ultrastructurally, in the epithelial-like portion of the first (mixed) tumor, peripheral arrays of contractile filaments were detected along with well-developed desmosomes. In the second (spindled) case, peripheral contractile filaments and attenuated desmosomes were also seen. In the third case, a huge number of mitochondria, some desmosomes, and actin-type microfilaments were found. In the fourth case, desmosomes and punctate subplasmalemmal densities, in addition to numerous mitochondria, were documented. In all cases an external basal lamina were present, which was discontinuous in the first three cases and almost continuous in the fourth. These tumors were respectively designated as mixed tumor, myoepithelioma of the classic type, myoepithelioma of oncocytic type with biphasic cell architecture, and true oncocytoma. So far, all tumors have followed benign clinical courses (median follow up: 12 months). Comparisons with similar tumors of other sites are drawn, and suggestions for considering all of them as members of the same myoepithelial-derived tumor family are given.- - - - - - - - - - ranking = 1keywords = spindle (Clic here for more details about this article) |
2/9. Nested stromal epithelial tumor of the liver: six cases of a distinctive pediatric neoplasm with frequent calcifications and association with cushing syndrome.Rare cases of nonhepatocytic mixed stromal and epithelial tumors of the liver with associated calcification and ossification have been described previously. We report 6 similar cases in children, including 2 cases associated with ectopic ACTH production. The patients were between 2 and 14 years of age at diagnosis. All tumors presented as a solitary liver mass with no extrahepatic involvement. Two adolescent females with palpable abdominal tumors presented with cushing syndrome that abated after excision of the tumors. The other children had tumors identified incidentally on imaging studies or at laparotomy. All tumors were well circumscribed, ranging in size from 4.0 to 30.0 cm in greatest diameter. Histologically, they shared an organoid arrangement of cellular nests that were comprised of an admixture of both spindled and epithelioid cells. These cellular nests were surrounded by a band of delicate myofibroblasts and set in a dense fibrous stroma that contained slit-like to dilated blood vessels. A variable proliferation of bile ducts extended from the fibrous stroma and focally surrounded the cellular nests. One case showed a sheet-like overgrowth of the nested cells with associated necrosis. The cellular nest cells were immunoreactive for EMA, CD56, neuron specific enolase, pan-cytokeratin (4 of 6 cases), vimentin (5 of 6 cases), and WT-1 amino terminus (4 of 6 cases). Cytokeratin and EMA stained mostly epithelioid nest cells, with vimentin and WT-1 staining predominantly the spindled nest cells. The 3 cases from adolescent females showed immunoreactivity for ACTH in the nested cell population but not in the surrounding stromal cells. Immunohistochemical stains for synaptophysin and chromogranin were negative in all cases. Psammomatous calcifications were present focally in 2 cases and were extensive in 3 cases. Ossification or osteoid formation was present in 4 cases. The 1 patient whose tumor had sheet-like overgrowth of the nested cell population had a local recurrence with multiple hepatic nodules 1 year following the original resection. A 2-year-old patient has been subsequently diagnosed with nephroblastomatosis and wilms tumor of the kidney. Follow-up information was available in an additional 3 patients with no tumor recurrence or metastatic disease at 2, 3, and 14 years.- - - - - - - - - - ranking = 0.5keywords = spindle (Clic here for more details about this article) |
3/9. Primary gastrointestinal stromal tumor of the esophagus in an hiv-positive patient.We describe a rare case of malignant gastrointestinal stromal tumor (GIST) of the esophagus presenting in an hiv-positive man. Not only did the tumor arise from an unusual anatomic site for GIST, namely, the esophagus, but it also had a predominant epithelioid cell morphology that is uncommon and preferentially associated with aggressive behavior. Exhaustive immunohistochemical studies showed strong reactivities to the classic GIST marker, CD34, and to the current more sensitive and more specific GIST marker, CD117/ c-kit protein. This immunophenotype corresponded to that of stromal tumors arising in the more common sites like stomach and small intestine as well as to that of a reported series of esophageal GISTs in the general population. Mutations of the c-kit protein was detected in the tumor, confirming previous observations. This further documents that esophageal GIST and the more common benign esophageal spindle cell lesions are pathologically distinct entities and despite its rarity, esophageal GIST should be recognized by pathologists and clinicians. The occurrence of this tumor in an hiv-positive patient is coincidental, and it resulted in an extremely unusual metastatic site that has not been reported for GISTs.- - - - - - - - - - ranking = 0.60024547686993keywords = spindle cell, spindle (Clic here for more details about this article) |
4/9. Incidental stromal-predominant mixed epithelial-stromal tumors of the kidney: a mimic of intraparenchymal renal leiomyoma.CONTEXT: Mixed epithelial-stromal tumor of the kidney is a recently recognized benign renal tumor that usually occurs in adult women and typically forms a sizable lesion with solid and cystic areas. The recognized morphologic spectrum of this recently described entity is evolving. OBJECTIVE: To review the clinicopathologic features of 3 small mixed epithelial-stromal tumors of the kidney that were incidental findings in kidneys removed for other reasons. DESIGN: The clinical presentation and morphologic findings of the 3 cases were reviewed. A panel of immunohistochemical stains was performed. SETTING: Academic medical center. RESULTS: All 3 lesions contained predominantly fascicles of smooth muscle mimicking leiomyoma, but they also had cellular subpopulations of smaller, mullerian-appearing stromal cells. Tubules present within the lesion were most abundant at the periphery, suggesting that they might be entrapped. Although only the spindled smooth muscle cells were immunoreactive for muscle markers desmin and actin, both the spindled smooth muscle cells and the cellular mullerian-appearing stromal cells demonstrated diffuse nuclear labeling for estrogen and progesterone receptors. CONCLUSIONS: Mixed epithelial-stromal tumor of the kidney may present as an incidental stromal-predominant lesion within the kidney. Such lesions are easily confused with leiomyomas or stromal-predominant angiomyolipomas.- - - - - - - - - - ranking = 0.5keywords = spindle (Clic here for more details about this article) |
5/9. Mixed epithelial and stromal tumor of the kidney in a 12-year-old girl.Mixed epithelial and stromal tumor of the kidney (MESTK) is a rare kidney neoplasm that almost exclusively occurs in perimenopausal women, and long-term estrogen replacement is relevant to its pathogenesis. Herein is described an atypical case of MESTK uncovered in a 12-year-old premenarcheal girl without a history of prior estrogen use. On surgical specimen it was found that the well-circumscribed tumor measuring 14 cm arose from the lower pole of the right kidney, showing solid and fibrous-cystic areas. Microscopically, it was composed both of epithelial structures similar to renal tubules and stroma comprising non-specific spindle cells. Some intratumoral tubules showed affinities to distal-nephron-specific lectins, and those immunoreactive for proximal-tubule-specific CD15 were also present. In addition, primitive ductal structures were reactive both for CD15 and lectins, but immature epithelial elements typical of nephroblastoma were absent. Spindle cells were positive for actin, desmin and vimentin, and expressed progesterone and estrogen receptors. The tumor was comparable with MESTK, although some epithelia were associated with the immunophenotype of proximal tubules. The patient was free of disease postoperatively for 40 months. In the present case, remnants of the primitive periductal mesenchyme might be promoted to neoplastic cells by a sex-steroid surge during puberty.- - - - - - - - - - ranking = 0.60024547686993keywords = spindle cell, spindle (Clic here for more details about this article) |
6/9. Benign mixed epithelial and stromal tumor of the kidney: imaging findings.Three cases of mixed epithelial and stromal tumor of the kidney with their imaging findings are described; these cases have not been reported previously in the radiology literature. This benign tumor contains epithelial and spindle cell stromal components and arises exclusively in adult women. It is characterized morphologically by a solid and cystic nature with delayed enhancement.- - - - - - - - - - ranking = 0.60024547686993keywords = spindle cell, spindle (Clic here for more details about this article) |
7/9. Mixed epithelial and stromal tumor of the kidney.A 42-year-old female presented with intermittent left flank pain for 2 years. She developed gross hematuria 1 month prior to seeking help. Intravenous pyelography showed filling defects within the lower portion of the left collecting system and renal pelvis causing hydronephrosis. Abdominal computed tomography revealed a huge cystic heterogenic tumor about 20 cm in largest diameter occupying the entire left kidney. A left radical nephrectomy was performed without complications. The pathology report confirmed the diagnosis of mixed epithelial and stromal tumor of the kidney. From pathologic survey, the spindle cells of this tumor were positive for muscle markers and expressed estrogen and/or progesterone receptors. We suggest that a mixed epithelial and stromal tumor of the kidney should be considered in all cystic renal tumors presenting in perimenopausal women.- - - - - - - - - - ranking = 0.60024547686993keywords = spindle cell, spindle (Clic here for more details about this article) |
8/9. Benign mixed epithelial and stromal tumor of the kidney.A 51-year-old, perimenopausal, female patient with 1-month history of right flank pain who was diagnosed with a renal mass and underwent nephron-sparing partial nephrectomy is presented. The renal mass was found to be a benign, biphasic tumor composed of an epithelial component, consisting of ducts of variable size scattered within a mesenchymal component, composed of spindle cells arranged in sheets and fascicles. No atypia, mitosis, or necrosis was found. The spindle component shows desmin, smooth muscle actin, and estrogen and progesterone receptor positivity immunohistochemically. The diagnosis of benign mixed epithelial and stromal tumor of the kidney is rendered. No recurrent disease has been detected during 2 years of follow up.- - - - - - - - - - ranking = 0.85024547686993keywords = spindle cell, spindle (Clic here for more details about this article) |
9/9. Benign mixed epithelial and stromal tumor of the kidney.We describe a distinctive benign tumor of the kidney in a 48-year-old woman, which was composed of well differentiated ducts set in the spindle cell stroma which was muscle actin, smooth muscle actin and desmin positive, and was morphologically similar to the ovarian stroma. No immature appearing epithelial renal or mesenchymal tissue was present in the tumor. Histologically, the tumor differed from the nephrogenic adenofibroma and the rare cases of adult Wilms tumors, mesoblastic nephromas and cystic nephromas.- - - - - - - - - - ranking = 0.60024547686993keywords = spindle cell, spindle (Clic here for more details about this article) |