Mesenteric schwannoma: an unusual cause of abdominal mass.

Schwannomas (or neurilemmomas) are slow-growing mesenchymal neoplasms of the peripheral nerve sheath that may arise at almost any anatomical site. Mesentery schwannoma is extremely rare, with less than ten previously described cases. We present the case of a 38-year-old woman with arterial hypertension and chronic kidney disease with an abdominal painless mass of two years duration and an inconclusive pre-operative clinical diagnosis; she was successfully treated by complete surgical resection of the mass. The aim of this report is to recognize the possibility of schwannomas in the differential diagnosis of abdominal slowly growing tumors.

Mesenteric schwannoma: an unusual cause of abdominal mass

Schwannomas (or neurilemmomas) are slow-growing mesenchymal neoplasms of the peripheral nerve sheath that may arise at almost any anatomical site. Mesentery schwannoma is extremely rare, with less than ten previously described cases. We present the case of a 38-year-old woman with arterial hypertension and chronic kidney disease with an abdominal painless mass of two years duration and an inconclusive pre-operative clinical diagnosis; she was successfully treated by complete surgical resection of the mass. The aim of this report is to recognize the possibility of schwannomas in the differential diagnosis of abdominal slowly growing tumors (AU)

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Phosphaturic mesenchymal tumors. Survey of 8 cases from a single Mexican medical institution.

Phosphaturic mesenchymal tumor (PMT) is a morphologically heterogeneous soft tissue and bone neoplasm, producing a paraneoplastic syndrome due to phosphate wasting. These tumors produce fibroblast growth factor 23, which is implicated in renal tubule phosphate loss. Medical records of patients seen from 1999 to 2013 with osteomalacia associated or not with a tumor were reviewed. Clinical and laboratory data, radiographic studies, and follow-up of 8 patients were tabulated. Histologic features and the immunoprofile of the tumors were analyzed. There were 208 patients with osteomalacia, but only 8 (3.84%) had osteomalacia associated with a tumor. The median age of the patients was 40 years. The tumor size ranged from 1.5 to 4 cm. Five were located in soft tissues and skin; and 3, in bones. Osteomalacia symptoms lasted from 2 to 14 years with a median of 6 years. Laboratory data showed hypophosphatemia and phosphaturia in all patients. All tumors were histologically benign. Histologically, the salient features were a hemangiopericytoid pattern, chronic hemorrhage, and microcystic areas. All neoplasms were diffusely positive for vimentin and focally positive for epithelial membrane antigen, CD34, and S-100 protein. Ki-67 was positive in approximately 10% of neoplastic cells in 2 cases and less than 1% in the remainder. We report 8 cases of PMTs producing osteomalacia, from a single third-level Mexican medical institution. These tumors occurred in soft tissues, skin, and bones. All tumors were benign, small, not easily detected by physical examination and diagnosed due to the metabolic abnormalities.

Cystadenomas of the liver and extrahepatic bile ducts: Morphologic and immunohistochemical characterization of the biliary and intestinal variants.

Cystadenomas of the liver and extrahepatic bile ducts (EHBD) are uncommon but distinctive neoplasms whose terminology and epithelial phenotype have been a source of controversy. We reviewed 20 cases, 16 arising in the liver and 4 in the EHBD. Eighteen patients were women, with a mean age of 36.5 years. Eighteen tumors were multiloculated and 2 were unilocular. The tumor size ranged from 4 to 29 cm (average, 11 cm). The cyst fluid in 13 tumors was described as serous, in 2 as clear, in 2 others as hemorrhagic, and in 1 as serous and mucinous. Only in 2 tumors was the fluid described as mucinous. In 18 cystadenomas, the predominant epithelial lining consisted of a single layer of cuboidal or low-columnar nondysplastic cells similar to those of the gallbladder or bile ducts. This epithelial lining was strongly positive for cytokeratins 7 and 19, and focally positive for MUC1. Only 2 cystadenomas showed predominant intestinal differentiation characterized by mature goblet cells and columnar absorptive cells. These cells expressed CDX2, MUC2, and cytokeratin 20. Admixed with the goblet and columnar cells, there were serotonin-containing cells and Paneth cells. These 2 tumors showed extensive areas of high-grade dysplasia and invasive adenocarcinoma with intestinal phenotype. A subepithelial ovarian-like stroma was present in all tumors. None of the patients died of the tumors. We believe that the term mucinous cystic tumor recommended by the World Health Organization for all cystadenomas of the liver and EHBD is a misnomer.

Association of urothelial carcinoma of the renal pelvis with papillary and medullary thyroid carcinomas. A new sporadic neoplastic syndrome?

We describe 2 adult women (72 and 54 years), 1 with a low-grade noninvasive papillary urothelial carcinoma of the renal pelvis, who 14 years later developed a papillary carcinoma in 1 thyroid lobe and a medullary carcinoma in the contralateral lobe. Both neoplasms were similar in size and appeared symmetrical. Despite its small size, the medullary carcinoma metastasized in multiple cervical lymph nodes. The second patient had a high-grade invasive papillary urothelial carcinoma of the renal pelvis that infiltrated the renal parenchyma and metastasized in one of the lungs. Five months later, a papillary carcinoma was discovered in the thyroid gland. The 2 papillary thyroid carcinomas were of the follicular variant. Adjacent to 1 papillary carcinoma, there was a dominant nodule of a colloid and adenomatous goiter. The medullary carcinoma contained stromal amyloid and was immunoreactive for calcitonin and carcinoembryonic antigen. There was no C-cell hyperplasia (medullary carcinoma in situ). The 2 patients are alive, 1 is living with pulmonary metastasis from the high-grade urothelial carcinoma. Twelve cases of this neoplastic association were registered in the Survey, Epidemiology, and End Results Program from 1980 to 2009. We believe that the combination of these unusual neoplasms in the same patient may represent a new sporadic neoplastic syndrome.

Neuromas mucosos de localización laríngea en una neoplasia endocrina múltiple 2B / Multiple mucosal neuromas in the larynx as part of a multiple endocrine neoplasia type 2B

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Hepatocellular carcinoma arising in a telangiectatic hepatocellular adenoma.

Telangiectatic hepatocellular adenoma is a rare, recently recognized subtype of benign liver tumor that may very rarely undergo transformation into hepatocellular carcinoma. We report an unusual case of a 75-year-old woman with no history of oral contraceptive use that underwent malignant transformation of a telangiectactic hepatocellular adenoma. No risk factors for adenoma development were identified in this otherwise healthy woman. Radiological characteristics, gross features and histopathology are herein described. In conclusion, telangiectatic hepatocellular adenoma can undergo malignant transformation. Further studies are needed to better clarify the factors associated with malignant progression.