Unusual uveal tract tumor: mesectodermal leiomyoma of the ciliary body

Benign smooth muscle tumor, leiomyoma, can occur throughout the whole body, including the most common sites of the genitourinary and gastrointestinal tracts, less frequently in the skin, and rarely in the deep soft tissue or uveal tract. A 23-year-old Chinese woman presented with a 4 month history of a pigmented ciliary body mass in her left eye. The tumor's clinical appearance and ancillary data were initially consistent with malignant melanoma. However, instead of enucleation, sclerotomy with a tumor biopsy was performed because of the patient's young age and the possibility of benign tumors. Under light microscopy, tumor cells were short spindle- or ovoid-shaped with fine nuclear chromatin and fibrillary cytoplasmic processes resembling neural tissue. Although the tumor displayed neurogenic morphology, it showed strong reactivity for alpha-smooth muscle-specific actin and h-caldesmon, and was negative for neurogenic markers, except CD56, by immunohistochemistry. Primary mesectodermal leiomyoma of the ciliary body was diagnosed because of both the myogenic and neurogenic characteristics. The tumor biopsy or intraoperative frozen section is suggested for accurate pathological diagnosis before enucleation. In a review of the literature, only 14 cases have been reported. Seven cases (50%) were subjected to enucleation and eventually showed a benign mesectodermal leiomyoma. This case report provides novel expression of h-caldesmon and CD56 by the tumor cells of mesectodermal leiomyoma.     

Recurrent mesectodermal leiomyoma of the ciliary body: a case report

A 19-yr-old woman with a previous history of a mass of the right ciliary body presented with a decreased visual acuity of right eye. Clinicoradiologic examinations suggested a recurrent mass of the ciliary body. Enucleation of the right eye was performed under the impression of malignant tumor. On microscopic examination, the tumor was a mesectodermal leiomyoma of the ciliary body. On immunohistochemistry, the tumor cells were reactive to smooth muscle actin and vimentin, but not reactive to cytokeratin, S-100 protein, neurofilament, desmin, epithelial membrane antigen, HMB-45, glial fibrillary acidic protein, and synaptophysin. Electron microscopy revealed numerous thin longitudinally placed myofilaments and focal densities in the cytoplasms. In the review of the literature, only 27 cases of mesectodermal leiomyoma of the ciliary body were reported, however, there was no report of recurrent cases. Mesectodermal leiomyoma should be differentiated from other orbital spindle-cell tumors such as amelanotic melanomas and glial tumors. Immunohistochemical and electron microscopic studies may be useful for the correct diagnosis by showing smooth muscle differentiation in the tumor cells.     

Mesectodermal leiomyoma of ciliary body

A 37-year-old woman had a mass in her left ocular globe. Uveal melanoma was suspected and enucleation was performed. Microscopically, the lesion proved to be a typical case of mesectodermal leiomyoma of the ciliary body. According to some authors, the peculiar neural appearance of this tumor could be the reflection of its probable origin from mesectodermal smooth muscle. Immunohistochemical analysis showed reactivity for muscle-specific actin and negativity for desmin, S-100 protein, HMB-45, EMA, and GFAP. Our results do not support the proposed neuroectodermical origin of this tumor, since coexpression of muscular and neural markers was not observed.     

Skeinoid Fibers in Mesectodermal Leiomyoma of the Ciliary Body

Unlike smooth muscle elsewhere in the body, the smooth muscle of the iris and ciliary body is derived from neuroectoderm (mesectoderm). Leiomyomas that arise from the ciliary body, and therefore are of mesectodermal origin, may resemble spindle cell neurogenic tumors by light microscopy. They show positive immunostaining for smooth muscle actin but negative staining for neural markers. Ultrastructurally, the cells have the features of smooth muscle cells. The authors report a typical case of mesectodermal leiomyoma in a 47-year-old woman in which skeinoid fibers, considered to be an ultrastructural marker of neurogenic spindle cell tumors, were frequent together with other ultrastructural features often seen in neuroglial cell tumors. The findings indicate that mesectodermal leiomyoma is unique in its histogenesis as well as in its morphology.     

Leiomyoma in the posterior choroid: a case report

Smooth muscle tumor of the uveal tract is rare, and mostly located in the cilio-choroidal area. We report a unique case of posterior choroidal leiomyoma in a 27-yr-old man. Ophthalmoscopic examination disclosed an 11 mm-sized mass on the fundus two-disc diameters apart from the optic disc. With a suspicion of amelanotic melanoma, the globe was enucleated. The mass occupied the whole thickness of choroidal stroma beneath the pigmented retinal epithelium and composed of spindle cells arranged in intersecting fascicles. Immunohistochemical studies demonstrated immunoreactivities of the tumor cells for smooth muscle actin, desmin, and vimentin. Ultrastructurally, numerous intracytoplasmic filaments with fusiform focal densities, scattered segmental external laminae, subplasmalemmal densities, and pinocytic vesicles were noted. The leiomyoma in this case had several unusual features in that it was confined to the posterior choroid with no relation to the ciliary body, occupied the whole stroma of the choroid instead of suprauveal location, and occurred in a young male. It is important to include choroidal leiomyoma in the differential diagnosis of choroidal tumors.     

677例子宫平滑肌肿瘤的病理诊断

目的：探讨子宫平滑肌肿瘤的病理诊断。方法：对677例子宫平滑肌肿瘤重新观察肿瘤细胞密度,异型性,核分裂象,瘤细胞凝固性坏死和浸润性边缘,作出诊断。结果：普通平滑肌瘤654例,特殊组织类型平滑肌瘤21例（富于细胞型7例,畸异型4例,不典型性9例,核分裂活跃型1例）,恶性潜能未定型平滑肌肿瘤1例,平滑肌肉瘤1例,普通子宫平滑肌瘤核分裂与月经周期显著相关,4例特殊组织类型平滑肌瘤可见肿瘤血管内生长,随访表明特殊组织类型平滑肌瘤为良性经过。结论：特殊组织类型子宫平滑肌瘤虽因形态有异,而导致误诊,但其生物学行为均属良性。     

睫状体肿瘤18例临床病理分析

目的 探讨睫状体(ciliary body,CB)原发性肿瘤的临床特点、组织学特征、诊断及鉴别诊断.方法 收集18例CB原发性肿瘤的临床病理资料,采用免疫组化及特殊染色检测,进行组织形态学分析,并复习相关文献.结果 18例CB原发性肿瘤中,黑色素瘤8例(44.44％),黑色素细胞瘤3例(16.67％),平滑肌瘤3例(1...     

Vascular leiomyoma of the lung arising from pulmonary artery

Leiomyoma of the lung is extremely rare. The entity is not described in WHO blue book. Less than 100 cases of leiomyoma of the lung have been reported in the literature. However, vascular leiomyoma has not been reported in the literature, to the author’s best knowledge. Herein reported is the first case of vascular leiomyoma of the lung arising from smooth muscles of the pulmonary artery. A 62-year-old woman (non-smoker) was found to have a small tumor in the upper lobe in the right lung in routine check. Imaging modalities including CT demonstrated no metastatic lesions. Although clinical cytology and biopsy revealed no malignant cell, right upper lobectomy was performed under the clinical diagnosis of lung carcinoma. Grossly, a white tumor of 1 x 0.8 cm was recognized in the lung. Microscopically, the tumor was connected to the pulmonary arteries. The tumor was composed of mature smooth muscles. Small pulmonary arteries are embedded in the tumor. No lymphatics were seen. Immunohistochemically, the tumor cells were poisitive for alpha-smooth muscle actin, vimentin and Ki-67 (labeling 2%). However, they were negative for cytokeratin (CK) AE1/3, CK CAM5.2, desmin, S100 protein, p53, CD34, KIT, HMB45, estrogen receptor, progesterone receptor, and myoglobin. A pathological diagnosis of primary vascular leiomyoma arising from the smooth muscle of pulmonary artery was made. The patient is now free from tumor, and is now alive 10 year after the operation.     

Actin expression in neural crest cell-derived tumors including schwannomas, malignant peripheral nerve sheath tumors, neurofibromas and melanocytic tumors

Tumors that originate from neural crest-derived cells represent a heterogeneous group of neoplasms including benign and malignant tumors with melanocytic and schwannian differentiation. The immunophenotype of these tumors is well known but little is known about the expression of smooth muscle/myofibroblastic markers in these tumors. A total of 590 neural crest-derived tumors (50 benign schwannomas, five malignant peripheral nerve sheath tumors, 80 neurofibromas, 240 nevocytic nevi, 115 primary melanomas, and 100 melanoma metastases) were studied with respect to α-smooth muscle actin and muscle-specific actin expression. α-Smooth muscle actin and muscle-specific actin-positive tumor cells with a co-expression of S-100 protein were found in one benign schwannoma, one primary cutaneous melanoma, and four melanoma metastases. Four of these cases were examined ultrastructurally, but typical actin filaments with focal densities were not found in any of the four. Other immunohistochemical markers examined including desmin, h-caldesmon and smooth muscle myosin heavy chain were negative in the tumor cells. The present results suggest that neural crest-derived tumors could show expression of α-smooth muscle actin on rare occasion.     

Breast leiomyoma: a case report and review of the literature

Breast leiomyoma is a rare and benign tumor which arises from a smooth muscle in nipple and areola or smooth muscle metaplasia of myoepithelial cells or myofibroblastic cells. Common differential diagnosis of the breast leiomyoma was as follows: fibroadenoma, myoepithelioma, phyllodes tumor, and leiomyosarcoma. We present here a rare case of solitary leiomyoma of the breast. We described a case of breast leiomyoma diagnosed in an otherwise healthy 37-year-old woman at the Rajaee Hospital. The patient presented with a palpable mass in her right breast since 2 years. Physical examination showed a mobile and smooth mass, without any axillary lymphadenopathy. The radiologic examinations revealed a well-circumscribed ovoid mass, 5 cm in diameter. Excisional biopsy disclosed a well-circumscribed cellular tumor by interlacing fascicles of spindle cells with fibrillary and eosinophilic cytoplasm. The tumoral cells were immunoreactive for smooth muscle actin. There were not any evidences of disease recurrence for 20 months of follow up. Histopathological study and immunohistochemical examinations help in the discrimination between leiomyoma and other benign and malignant breast lesions and determination of outcome.     

Myxoid leiomyoma of the vulva mimicking aggressive angiomyxoma

A case of vulvar leiomyoma with extensive myxoid change in a 40 year old female is described. The tumor had a unique connection with a non-degenerative leiomyoma that compressed the rectum and the bladder. Scattered smooth muscle cells in a loose myxoid stroma were immunoreactive for desmin. Fibroblast-like spindle cells were immunoreactive for vimentin but not for desmin. The initial, although incorrect, pathological diagnosis of the tumor was aggressive angiomyxoma based on the similarity in both clinical and pathological aspects with this more invasive tumor. Myxoid vulvar leiomyoma should also be differentiated from angio-myoflbroblastoma. The key to the differential diagnosis is the presence of interlacing smooth muscle cells and an awareness of tendency toward myxoid change in vulvar leiomyomas.     

246例子宫平滑肌肿瘤临床病理分析

目的:探讨子宫平滑肌肿瘤临床病理特征.方法:对246例子宫平滑肌肿瘤的临床病理资料进行回顾性分析.结果:子宫平滑肌肿瘤发病高峰年龄为40～50岁,可伴内膜增生或腺肌病,同时与卵巢、宫颈多种良恶性病变并存.246例子宫平滑肌肿瘤中,91.4%为普通型良性平滑肌瘤;6.9%为平滑肌瘤特殊组织学类型;0.8%为平滑肌肉瘤;0...     

Cytomorphology of a mixed pigmented/nonpigmented pleomorphic adenoma of the ciliary body: A diagnostic pitfall in the evaluation of intraocular tumors

Intraoperative cytology is an alternative and sometimes preferred method to frozen section in the rapid evaluation of surgical biopsies. This report describes the cytological, histological, and immunohistochemical features of a case of mixed pigmented/non-pigmented pleomorphic adenoma of the ciliary body with clinical and morphological features reminiscent of malignant melanoma. The characteristic cyto-histomorphology of this unusual tumor and its distinguishing features from malignant melanoma are discussed. Diagn Cytopathol 1996;14:259–262. © 1996 Wiley-Liss, Inc.     

Cellular leiomyomas of the stomach in 49 patients

The cellular leiomyoma of the stomach is composed of tightly packed, generally uniform spindle cells arranged in palisades, whorls, or interdigitations. Although these neoplasms have been variably considered to arise from gastric smooth muscle or Schwann cells, the morphogenesis is incompletely resolved. Perhaps they derive from a multipotential gastric stromal stem cell that is capable of differentiating toward smooth muscle. A cellular gastric tumor composed of fairly uniform, elongated spindle cells is unlikely to be malignant. Of 49 such tumors, only one metastasized. The combination of an increased mitotic rate and large tumor size is possibly indicative of malignant potential.     

Leiomyoma with nuclear atypia: Rare diseases that present a common diagnostic problem

Leiomyoma with nuclear atypia describes a group of uterine smooth muscle tumors with a wide range of histologic and clinical presentations and remarkable nuclear atypia. These include fumarate hydratase-deficient leiomyoma (FH-LM), intravenous leiomyomatosis (IV-LM), and leiomyoma with bizarre nuclei (LM-BN). Other uterine mesenchymal tumors, such as perivascular epithelioid tumor (PEComa) and inflammatory myofibroblastic tumors (IMFT) are the mimickers of leiomyoma with nuclear atypia. LM-BN is the primary tumor model with a long history in gynecologic pathology, but the histogenesis of LM-BN remains largely unknown. Differentiating LM-BN from other benign variants, tumors with uncertain malignant potential (STUMP), or fully malignant leiomyosarcoma (LMS) can be diagnostically challenging. Recent progress has improved the diagnosis of many types of leiomyoma with nuclear atypia based on their specific histology and molecular alterations. LM-BN is now a diagnosis of exclusion. In this article, I review the history of leiomyoma with nuclear atypia and compare the clinical, histologic, and molecular features of LM-BN with those of its mimics. In particular, I highlight the current progress made in molecular genetics and pitfalls in the diagnosis of different myogenic tumors with nuclear atypia.     

Fine-needle aspiration biopsy of metastatic malignant melanoma resembling a malignant peripheral nerve sheath tumor

We report a case of metastatic malignant melanoma resembling a malignant peripheral sheath tumor, which posed a significant diagnostic challenge. The patient is a 76-year-old male, who presented in the emergency room with bilateral chest pain exacerbated by inspiration. The pain was present for 3 week and was not exacerbated by physical exercise. The diagnostic workup revealed bilateral parenchymal pulmonary infiltrates. The CT-scan guided fine-needle aspiration and the core biopsies of the largest pulmonary lesion revealed high-grade spindle cell neoplasm with individual cell apoptosis and necrosis. The immunohistochemical profile on the cell block showed that the cells are positive for Vimentin. The S-100 stain showed only focal positivity. The immunohistochemical stains for HMB45, Melan A, pancytokeratin, and smooth muscle actin were negative. Five years ago the patient was diagnosed with melanoma on the back with Clark level of IV. The melanoma was excised with clear margins and sentinel lymph nodes were negative. Careful examination of patient's previous slides revealed an area of spindle cell melanoma adjacent to a nodular type melanoma. Based on the patient's previous history, current clinico-pathologic presentation and immunohistochemical profile, the diagnosis of metastatic malignant melanoma resembling peripheral nerve sheath tumor was favored over the diagnosis of metastatic malignant spindle cell neoplasm of unknown primary site, which by itself is very rare clinical scenario.     

Leiomyoma of the prostate--a rare mesenchymal tumor: a case report

Prostatic enlargement due to benign adenomatous hyperplasia is very common in elderly males. However, benign mesenchymal tumors, especially true leiomyoma, are rare in prostate. True prostatic leiomyoma has been defined by Kaufman and Berneike as a smooth muscle tumor within the prostate or juxta-prostatic in position, devoid of glandular elements. The recognition of leiomyoma is important because of the potential of malignancy in such cases, and histopathology is the only tool to do so. We describe the case of a 65-year-old male presenting with urinary obstruction for eight months. Per rectal examination revealed an enlarged firm prostate, a trucut biopsy from which showed only stromal tissue. A suprapubic prostatectomy was performed, and histopathological examination revealed a benign smooth muscle tumor (confirmed by immunohistochemistry), in absence of glandular hyperplasia. Thus, a diagnosis of true leiomyoma of the prostate was made. True leiomyoma is a rare tumor in prostate, which can be diagnosed only on histopathological examination. In addition, careful intra-operative and extensive pathologic assessment is mandatory for predicting the potential behaviour.     

Pulmonary benign metastasizing leiomyoma: a case report

Pulmonary benign metastasizing leiomyoma (PBML) is a rare entity usually occurring in females with history of uterine leiomyoma, and it is preferential to metastasize to the lung and appears as a histopathologic benign tumor of smooth muscle origin. In this article, the clinical and pathological data from 1 patient with PBML were analyzed. Chest CT scan showed that multiple well-defined nodules in the both lobes of the lungs. The tumor cells in the lung were well differentiated, and the pattern of tumor was similar to the original tumor. IHC identified it originated from smooth muscle cells, consistent with the diagnosis of PBML. Positive staining of estrogen and progestogen receptors was detected in both the leiomyoma and the metastasizing lesions. During two years of observation, pulmonary function parameters were within normal limits and there was no evidence of tumor recurrence.     

Hepatic angiomyolipoma

Hepatic angiomyolipoma is a rare, benign, hepatic mesenchymal neoplasm found in both males and females, and most commonly in adult females. Angiomyolipoma occurs most commonly in the kidneys. The liver represents the second most frequent site of involvement. Hepatic angiomyolipomas are composed of varying amounts of smooth muscle cells, adipose tissue, and vessels. The smooth muscle cell component is the most specific to the diagnosis. The smooth muscle cells can have varying morphologies and are positive for homatropine methylbromide-45 but are negative for hepatocyte paraffin 1 and S100 protein. The definitive diagnostic study remains the histologic examination of the surgically resected lesion coupled with immunohistochemical stains. The differential diagnosis includes hepatocellular carcinoma, hepatic adenoma, leiomyoma, hepatoblastoma, melanoma, and gastrointestinal stromal tumor. The immunohistochemical staining pattern differentiates this lesion from other malignant and benign liver lesions. If the diagnosis of hepatic angiomyolipoma has been made, it can be followed conservatively or surgically resected.     

Leiomyomatous neoplasms of the lung: a clinical, histologic, and immunohistochemical study

A series of 12 pulmonary lesions initially diagnosed as leiomyomatous in origin were reviewed. The original slides were analyzed for a series of histological features, the patients' charts were reviewed for clinical presentation and follow-up, and the usefulness of immunohistochemistry was assessed. Three groups were noted after analysis. Group 1, or benign lesions (three cases), all occurred in premenopausal female patients who remain alive and well. Group 2, or leiomyosarcomas (five cases), mostly occurred in older females, were thought to originate in the uterus, and resulted in death in four patients. In one of three cases of metastatic leiomyosarcoma, estrogen receptor was identified. Group 3 (4 cases) consisted of other diagnoses, including leiomyomatosis, fibrous histiocytoma, metastatic malignant melanoma, and metastatic synovial sarcoma. Immunohistochemistry was useful in separating nonsmooth muscle tumors and demonstrated muscle marker expression in all benign and most malignant smooth muscle lesions. Criteria are proposed for the diagnosis of pulmonary leiomyosarcoma, whether primary or secondary. In addition, if strict criteria are applied, the term "benign metastasizing leiomyoma" should be abandoned.