Leiomyoblastoma of the uterus: an immunohistochemical and electron microscopic study of distinctive tumours with immature smooth muscle cell differentiation mimicking fetal uterine myocytes.

AIMS: We present three distinctive uterine tumours which exhibited immature smooth muscle differentiation mimicking smooth muscle cells of the fetal uterus. METHODS AND RESULTS: The patients were 45, 46 and 49 years old, and all of them had simple hysterectomies. Grossly, all tumours were present in the uterine body, and two of the three tumours were well demarcated 60-mm and 85-mm lesions, and the other tumour was a small 25-mm incidental lesion within multiple conventional leiomyomas. The tumours had varied histological features and were composed of round epithelioid, rhabdoid and large vacuolated cells intermingled with spindle-shaped cells to various degrees. Although their round vesicular nuclei showed mild to moderate variation in size, prominent nuclear atypia was not seen. Necrosis and mitotic figures suggesting biological aggressiveness were not present in any of the tumours. Immunohistochemically, tumour cells were intensely positive for desmin and alpha-smooth muscle actin, whereas positivity for heavy molecular weight caldesmon was restricted. In addition, two cases were positive for non-muscle myosin heavy chain (SMemb). Ultrastructurally, most tumour cells contained various amounts of intermediate filaments which were occasionally abundant and aggregated as in rhabdoid cells. Well-developed myofilaments with focal densities were observed in only a few tumour cells. Intermediate filaments and bundles of thin filaments without dense bodies were often intermingled and they occasionally formed distinctive complexes with many irregular dense body-like structures and crystalloid bodies. Other cytoplasmic organelles including rather rich mitochondria, some rough endoplasmic reticulum and free ribosomes were also common. CONCLUSIONS: These findings support their immature smooth muscle cell differentiation which mimics the mesenchymal cells of fetal uterus during 14-26 weeks of gestation. The term 'uterine leiomyoblastoma' is thought to be appropriate for describing these distinctive immature smooth muscle tumours.

Epithelioid cell's uterine leiomyoma uteri. A case report with immunohistochemical study.

In the present report we refer to a rare case of uterine leiomyoma Uteri with epithelioid cells, characterized by an omogeneous light cell's structure and by a lymphangiomatous like histological aspect. An immunohistochemical study was carried out, using both endothelial and cell surface markers, as well as vascular markers. This study has allowed us to exclude the angiogenic origin of the neoplasm. It has, furthermore, revealed how the lymphangiomatous like histological aspect, even though being a peculiar component of the tumor, is to be put in relation with the epithelioid cells' layout, which has been evidenced by the immunohistochemistry to be of muscular nature.

Leiomyoma of the male urethra: a case report and review of the literature.

We describe the case of a 48-year-old quadriplegic black man with history of C4-C5 cervical spine and cord injury secondary to a fall, who presented to the University of Cincinnati Medical Center Urology Service with obstructive symptoms at urination. A bulbous urethral stricture was diagnosed and subsequently resected with primary urethral reanastomosis. On pathologic examination, the surgical specimen contained an epithelioid leiomyoma at the site of the urethral stricture. Although leiomyomas of the female urethra are relatively common, we identified only 2 previously reported cases of leiomyomas of the male urethra in the English-language medical literature. To the best of our knowledge, we describe the third case of leiomyoma of the male urethra, the first of the epithelioid type.

Multilocular cystic epithelioid leiomyoma of the uterus with focal lymphangioma-like pattern: report of a case with immunohistochemical study.

We report a rare case of epithelioid leiomyoma of the uterus presenting as a multilocular cystic mass containing clear fluid. The histologic basis of cysts was the diffuse intratumoral cystic degeneration. Histologically, the presence of numerous cystic cavities of variable size raised the possibility that vascular abnormalities, such as hemangioma, lymphangioma, and diffuse cavernous angiomatosis, could be associated with epithelioid leiomyoma. An immunohistochemical study using endothelial cell and basement membrane markers, was helpful in excluding the vascular nature of the cystic cavities and revealed an unexpected focal lymphangioma-like pattern as a peculiar component of tumor.

Cutaneous epithelioid angioleiomyoma.

We describe an unusual dermal neoplasm with epithelioid morphology. A 44-year-old man presented with a solitary, tender, 4-mm nodule on the leg. Excisional biopsy showed several well-circumscribed dermal epithelioid tumor nodules, prominent vascularity, and smooth muscle differentiation. We suggest the term cutaneous epithelioid angioleiomyoma for this neoplasm. In a review of the literature, we found reports of two similar cases and a recent report describing five cutaneous epithelioid leiomyosarcomas. Cutaneous epithelioid angioleiomyoma represents a rare variant of dermal smooth muscle tumor and could represent the benign counterpart to the recently described epithelioid leiomyosarcoma of the skin.

Epithelioid leiomyoma of the breast with granular cell change: a case report.

A 42-year-old woman with an epithelioid granular cell leiomyoma of the right breast is reported. The cells were spindle to polygonal and displayed finely granular cytoplasm. The smooth muscle differentiation of this tumor was shown by the immunohistochemical positivity of the neoplastic cells with anti-alpha smooth actin and antidesmin antisera. Microfilaments with focal densities were present in the cytoplasm at an ultrastructural level. The granular cytoplasmic changes are related to a relevant number of lysosomes within the neoplastic cells.