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At least 91 records · Page 5Linked to original sources
PubMed2002

Solid adenoma with exclusive hepatocellular differentiation: a new variant among pancreatic benign neoplasms?

We report a unique, previously unreported pancreatic tumor with hepatoid differentiation associated with serous microcystic adenoma in a 70-year-old man. These two lesions localized, respectively, at the body and the tail of the pancreas, were found incidentally on abdominal ultrasonography. Serum alpha-fetoprotein was not increased and no hepatic lesion was displayed on computed tomography. A subtotal pancreatectomy with splenectomy was performed. The patient is alive and well 12 months after resection. Pathological examination showed a very unusual encapsulated solid tumor with hepatocytic differentiation, bile production and immunoreactivity for hepatocyte paraffin-1 antibody. The tumor cells were negative for endocrine (neuron-specific enolase, chromogranin A, synaptophysin) and acinar (amylase, trypsin) markers. Ultrastructurally, zymogen and neurosecretory granules were absent. The features of the tumor were almost indistinguishable from those of hepatocellular adenoma; therefore, we believe that this solid hepatoid tumor may represent a variant of pancreatic adenoma. Recognition of this entity is important because the only reported pancreatic hepatoid tumors to date have been malignant. The main differential diagnoses include hepatoid ductal adenocarcinoma, hepatoid acinar cell carcinoma, primitive hepatoid endocrine tumor, and metastatic hepatocellular carcinoma.

Adenoma↗
PubMed1995

Cutaneous angiomyxoma: a benign neoplasm distinct from cutaneous focal mucinosis.

We describe a cutaneous angiomyxoma on the head of a 38-year-old man without evidence of Carney's complex. Complete excision of the tumor appeared to be curative. Histologic examination revealed fibroblast-like cells embedded in a well-demarcated, lobulate, mucinous, and vascularized stroma with a delicate reticulin network. Immunohistologically, the stromal cells were consistently positive for vimentin and focally positive for smooth muscle A-actin but were negative for desmin, KP1, MAC387, factor XIIIa, CD34, Leu-7, and S-100. Cutaneous angiomyxoma appears to represent a myofibroblastic neoplasm that should be distinguished from cutaneous focal mucinosis.

Adult↗
PubMed1986

Adult-onset cyclic neutropenia is a benign neoplasm associated with clonal proliferation of large granular lymphocytes.

Human cyclic neutropenia occurs in children and adults. Adult-onset cyclic neutropenia is an acquired disease characterized by increased numbers of large granular lymphocytes (LGL), in contrast to childhood-onset cyclic neutropenia in which LGL counts are normal. We investigated the clonality of lymphocytes in these two groups of patients by assessing the rearrangement status of the T cell receptor beta chain gene. Patients with adult-onset cyclic neutropenia showed clonal rearrangement of the T beta gene whereas the children did not. Since LGL are known to have multiple regulatory effects on normal hematopoiesis, the finding of a clonal proliferation of this lymphocyte population implicates these cells in the pathogenesis of cyclic neutropenia.

Adult↗
PubMed1997

Cellular angiofibroma: a benign neoplasm distinct from angiomyofibroblastoma and spindle cell lipoma.

Four cases of a distinctive soft-tissue tumor of the vulva are described. They were characterized by occurrence in middle-aged women (39-50 years), small size (< 3 cm), and a usually well-circumscribed margin. The preoperative clinical diagnosis was that of a labial or Bartholin gland cyst in three of the four cases. The microscopic appearance was remarkably consistent and was characterized by a cellular neoplasm composed of uniform, bland, spindled stromal cells, numerous thick-walled and often hyalinized vessels, and a scarce component of mature adipocytes. Mitotic activity was brisk in three cases (up to 11 mitoses per 10 high power fields). The stromal cells were positive for vimentin and negative for CD34, S-100 protein, actin, desmin, and epithelial membrane antigen, suggesting fibroblastic differentiation. Two patients with follow-up showed no evidence of recurrence. The differential diagnosis of this distinctive tumor includes aggressive angiomyxoma, angiomyofibroblastoma, spindle cell lipoma, solitary fibrous tumor, perineurioma, and leiomyoma. The designation of "cellular angiofibroma" is chosen to emphasize the two principal components of this tumor: the cellular spindle cell component and the prominent blood vessels.

Adipocytes↗
PubMed2004

Infarcted adenomatoid tumor: a report of five cases of a facet of a benign neoplasm that may cause diagnostic difficulty.

We describe five cases in which adenomatoid tumors showed extensive necrosis, presumably due to infarction, and posed diagnostic difficulty. The tumors occurred in four males (three with epididymal tumors and one with an intratesticular tumor) and one female (with a parafallopian tube tumor) 35 to 44 years of age. Two of the men presented with acute scrotal pain simulating epididymitis, and two with a palpable mass. The parafallopian tube tumor was an incidental finding. The tumors were solitary, grossly well-circumscribed, uniformly solid masses that ranged in size from 1.1 to 3.5 cm. Microscopically, they were all characterized by central necrosis with pale mummified adenomatoid tumor identified at least focally but often overshadowed by nondescript necrotic tissue. Viable adenomatoid tumor was identified in all cases but was minor in amount in two of them. The necrosis was surrounded by a florid reactive process of fibroblasts and myofibroblasts that had plump nuclei often with prominent nucleoli, and occasional mitoses. Two of the epididymal cases had adjacent rete testis showing epithelial hyperplasia with hyaline globule formation. The microscopic appearance often suggested the possibility of a malignant neoplasm because of: 1) blurring of the normal relatively easily identifiable junction between adenomatoid tumor and adjacent tissue; 2) irregular pseudo-infiltration of fat by reactive tissue and adenomatoid tumor; 3) paucity of typical adenomatoid tumor due to the infarction and the fact that viable tumor usually showed a solid pattern; and 4) atypia of the associated reactive cells. This unemphasized feature of adenomatoid tumors may potentially lead to more aggressive therapy than warranted if it is not correctly interpreted.

Adenomatoid Tumor↗