Ultrastructure and histogenesis of the acral calcified angioleiomyoma.

We studied the ultrastructure, immunohistochemistry, and histogenesis of the acral calcified angioleiomyoma, observing three concentric zones: (a) pseudocapsular, thin, with spindle-shaped stromal cells (SCs), presenting scarce organelles and expressing CD34, (b) muscular, forming a ring, with smooth muscle cells of heterogenous phenotype (mainly in quantity and thickness of filaments, and in expression of h-caldesmon, αSMA, and desmin), and (c) central, extensive, calcified (spicular and/or star-shaped calcium deposits around collagen fibers), with pericytic involutive vasculature. The intratumoral vessels were thick (several layers of perivascular cells, with a continuum of phenotypes, resembling myopericytoma vessels) and thin (slit-like channels), without adventitial SCs or elastic material. The extratumoral vessels showed adventitial SCs (which contribute to form the tumor pseudocapsule), hyperplasia of the media and intima layers, and/or occlusion of the lumen by a wide, homogenous fibrotic central zone. Histogenetically, the collagenous matrix may act as a mineralization substrate and the calcifying modified pericytes as inductors; intratumoral vessels may originate from the peritumoral vessels or from the vessel where the tumor develops; and extratumoral vessel modifications, mimicking tumor features, concur with a minor repetitive trauma pathogenesis.

Cardiac angioleiomyoma in 44 cattle in Japan (1982-2009).

A retrospective study was performed on primary cardiac tumors found in 44 cattle during meat inspection in Japan, using histology, immunohistochemistry, and electron microscopy. The age of affected cattle ranged from 10 to 129 months; 82% were less than 3 years old. In 38 hearts, the tumor was solitary; the remaining 6 hearts had multiple masses. All tumors were subendocardial and involved the papillary muscles and/or cardiac valves. Two histologic patterns were recognized; both included giant cells. Pattern 1 was characterized by interlacing fascicles of spindle-shaped cells; pattern 2 resembled cavernous hemangioma. The 2 patterns coexisted and were linked by transitional zones. Given the immunohistochemical reactivity and ultrastructure, the spindle-shaped cells were identified as smooth muscle cells and the giant cells as endothelial cells. Single cell and multicellular angiogenesis by giant cells was observed. The tumors were classified as cardiac angioleiomyoma. Subendocardial multipotential mesenchymal cells, persistent tissue of the endocardial cushion, or valvular interstitial cells were suspected as the origin.

Primary composite angiogenic leiomyosarcoma-epithelioid angiosarcoma of the brain.

The authors describe a primary sarcoma of the brain with immunohistochemical and ultrastructural features of leiomyosarcoma as well as epithelioid hemangiosarcoma. The leiomyosarcomatous component consisted of spindle cells with well-developed external lamina, subsarcolemmal densities composed of microfilaments, pinocytic vesicles, and abundant intermediate filaments, and showed immunohistochemical reactions for smooth muscle actin. The epithelioid part of the tumor contained scattered cells reactive for alkaline phosphatase as well as CD31 and factor VIII. Many epithelioid cells were lipidized and remarkably similar to "stromal cells" of a hemangioblastoma. Occasional Weibel-Palade bodies, indicating endothelial differentiation, were present in scattered neoplastic cells. There were also cells with features intermediate between endothelium, pericytes and smooth muscle cells, and undifferentiated mesenchymal cells. The brain at the periphery of sarcoma showed conglomerates of well-differentiated capillaries, telangiectasias and small dysplastic arteries, features that raise the possibility of origin of this tumor from a preexisting vascular developmental abnormality.

Primary angioleiomyoma of the iliac bone: clinical pathological study of one case with flow cytometric DNA content and S-phase fraction analysis.

We report on a primary angioleiomyoma of the right iliac bone in a 28-year-old woman. To our knowledge this is the 16th reported case of a primary leiomyoma of bone, the 9th reported primary osseous angioleiomyoma and the first description of a primary angioleiomyoma located in the iliac bone. The problems of differentiating primary leiomyoma of bone from primary or metastatic leiomyosarcoma of bone are stressed. A literature review of primary leiomyomas of bone is presented.

Angiomyofibroblastoma of the vulva: a mitotically active variant?

A case of angiomyofibroblastoma in a 48-year-old woman is reported. The tumor occurred as a left vulval mass and was treated by simple excision. It was located in the subcutaneous tissue of the left vulva and was well circumscribed, measuring 2.8 x 2.7 x 2.5 cm. Microscopically, the tumor was composed of hypocellular and cellular areas with well-developed small vessels. Spindle or polygonal cells were arranged with perivascular accentuation in an edematous or fibrocollagenous background. Some spindle-shaped or polygonal stromal cells were also arranged in epithelioid nests. In some areas, mitoses were frequent (maximum 3/10 high-power field). Immunohistochemically, the stromal cells were positive for vimentin and desmin, but negative for alpha-smooth muscle actin, S-100, neurofilament, estrogen receptor, progesterone receptor, CD31 and CD34. The average labeling index of Ki-67 in stromal cells was 3.1%. Ultrastructural analysis demonstrated that the stromal cells adhered with primitive junctions and contained intermediate filaments with no focal density in the cytoplasm. These findings were consistent with angiomyofibroblastoma, although previously reported cases did not show so many mitoses. Therefore, this case was suggested to be a mitotically active variant.

Angiomyofibroblastoma of the vulva with sarcomatous transformation ("angiomyofibrosarcoma").

We report on a locally recurrent vulvar tumor in an 80-year-old woman that we believe represents the first example of malignant transformation of an angiomyofibroblastoma. The tumor was predominantly a typical angiomyofibroblastoma, composed of epithelioid or oval cells with eosinophilic cytoplasm that tended to cluster in small groups and around blood vessels. These areas merged imperceptibly with a high-grade sarcoma that resembled a myxoid malignant fibrous histiocytoma. The tumor cells in the benign areas were diffusely immunoreactive for vimentin; many cells were positive for smooth muscle actin, and focal positivity for muscle actin and desmin was observed. The tumor cells in the sarcomatous areas were diffusely positive for vimentin, but negative for smooth muscle actin, muscle actin, and desmin. No staining for keratin, S-100 protein, or CD34 was noted. Ultrastructural examination of the sarcomatous area showed that the cells had the features of fibroblasts. All previously reported cases of angiomyofibroblastoma have exhibited banal histologic features and have behaved in a benign fashion. This case shows that these tumors may rarely be associated with a malignant component, and the designation "angiomyofibrosarcoma" may be appropriate in such cases.

An angiomyoma with t(X;10)(q22;q23.2).

A t(X;10)(q22;q23.2) translocation was detected as the only chromosomal aberration in primary short-term cultured cells from an angiomyoma of a 58-year-old woman; 6p, 13q, and 21q rearrangements have been previously demonstrated by others in two cases of angiomyoma. This type of translocation has not been reported in other benign tumors including leiomyomas and angiomyomas, although it has been detected in an ependymoma. This is thought to be a third case of angiomyoma showing karyotypic abnormalities.

Primary intracranial pleomorphic angioleiomyoma--a new morphologic variant. An immunohistochemical and electron microscopic study.

BACKGROUND: Angioleiomyomas usually are benign subcutaneous neoplasms that occur most often in extremities of middle-aged individuals. Very few cases have been described in other locations; none along the neuroaxis. An intracranial example of angioleiomyoma displaying unusual morphologic features not seen in the typical peripheral variants of this tumor is described. METHODS: The tumor was studied with conventional histology, immunohistochemistry with morphometric calculation of proliferation index, immunoelectron microscopy, and DNA flow cytometry. RESULTS: The tumor was composed of large epithelioid and pleomorphic cells filled with intermediate filaments positive for desmin and vimentin. Scattered cells also expressed myosin and muscle-specific actin. Smooth muscle cell differentiation was confirmed by ultrastructural demonstration of subplasmalemmal dense bodies, attachment plaques, and discontinuous basal lamina. The proliferation index with proliferating cell nuclear antigen (PCNA) monoclonal antibody was 75.78%, whereas it was only 4.22% with Ki67 monoclonal antibodies adopted to paraffin material (MIB-1). CONCLUSION: The tumor represents a unique morphologic variant of a pleomorphic angioleiomyoma. Cellular pleomorphism and a strong reaction for PCNA in numerous cells suggested that the lesion was malignant. However, the absence of mitotic figures, a small number of Ki-67-positive cells, a diploic DNA pattern, and a low proliferation index in flow cytometry all supported the concept that this neoplasm represented an unusual histologic variant of benign angiogenic leiomyoma. Encapsulation and demarcation of the surgical specimen and the survival of the patient for more than 4 years without recurrence after resection support this interpretation.

Angiomyofibroblastoma of the vulva.

Angiomyofibroblastoma is a rare, myxoid tumor of the vulva. To date only 12 cases have been reported in the world literature. Patients are usually premenopausal and present with a vulval mass initially diagnosed as a Bartholin's cyst. The lesions are well circumscribed and range from 0.5 to 12 cm in size. Microscopically the tumors are characterized by high cellularity, numerous blood vessels, and plump stromal cells. Treatment is by surgical excision. There are currently no published reports of local recurrence or metastatic disease. Angiomyofibroblastoma should be differentiated from other neoplasms of the vulva where radical surgical treatment is indicated. A Case Report of angiomyofibroblastoma of the periclitoral region diagnosed in a postmenopausal woman is presented.

Electron microscopic examination of cutaneous lesions by the quick re-embedding method from paraffin-embedded blocks.

We attempted to evaluate whether Widéhn's quick re-embedding method from paraffin blocks is useful for dermatopathological diagnosis. Regarding fine preservation of nuclei, tono-fibrils and desmosomes of keratinocytes in normal skin, we could recognize no difference between the quick re-embedding method and traditional re-embedding methods. However, preservation of mitochondria and Birbeck granules in Langerhans cells was poor regardless of the method used. Furthermore, we studied the ultrastructural features of some viral skin diseases including molluscum contagiosum, herpes simplex, varicella-zoster and verruca vulgaris, and some skin tumors, including angioleiomyoma, angiosarcoma, Merkel cell carcinoma and amelanotic melanoma using the quick re-embedding method. We determined that all viral structures were sufficiently preserved by the quick method to observe the virions and development of the virus. Myofilaments and dense bodies of angioleiomyoma, Weibel-Palade bodies of angiosarcoma, neurosecretory granules of Merkel cell carcinoma and melanosomes of amelanotic melanoma were recognized by the quick method. From these results, we concluded that the quick re-embedding method is useful for the diagnosis of skin diseases, especially viral skin diseases and some skin tumors.

[Intravenous leiomyomatosis]. / Leiomiomatosis intravenosa.

A case of intravascular leiomiomatosis is presented. This gynecologic diseases is rare, although it can be of risk. A case is described with a review of the literature.