Mesectodermal leiomyoma of the ciliary body: report of a case and review of the literature

Mesectodermal leiomyoma of the ciliary body is a rare benign tumor with double (muscular and neural) differentiation. This neoplasm is considered to originate from the ciliary body smooth muscle, a neural crest derivative. We report a case of mesectodermal leiomyoma of the right eye occurring in a 53-year-old woman, who presented with significant decrease of visual acuity. A malignant melanoma was highly suspected on clinical evaluation, and the globe was enucleated. The tumor measured 1.2cm in greatest dimension, and consisted of spindle and ovoid cells with abundant fibrillary cytoplasmic processes. Immunohistochemical stains revealed positivity for smooth muscle actin, caldesmon, neuron-specific enolase, and CD56 antigen. A review of the 23 cases thus far reported in the literature shows a striking predilection for women, as well as significant difficulties in differentiating this tumor from malignant melanoma on clinical grounds.     

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.     

H-caldesmon expression in myofibroblastoma of the breast: evidence supporting the distinction from leiomyoma

AIMS: The ultrastructural detection of leiomyomatous rather than myofibroblastic features in some cases of myofibroblastoma of the breast led some electron microscopically orientated pathologists to doubt the commonly accepted myofibroblastic nature of such a tumour, so the alternative terms 'myogenic stromal tumour' or 'variant of leiomyoma' have been proposed. The aim of this study was to analyse the immunohistochemical expression of h-caldesmon, a reliable marker in distinguishing smooth muscle versus myofibroblastic cellular differentiation, in a large series of myofibroblastomas of the breast to clarify whether these tumours are basically leiomyomatous. Moreover, cases from primary myofibroblastic lesions of the breast, such as fibromatosis and inflammatory myofibroblastic tumour, were analysed to assess whether h-caldesmon expression parallels that observed in their soft tissue counterparts. METHODS AND RESULTS: Paraffin-embedded sections from 12 cases of myofibroblastoma, seven cases of fibromatosis, and one case of inflammatory myofibroblastic tumour were evaluated immunocytochemically for the expression of h-caldesmon. As expected, all myofibroblastic lesions failed to express h-caldesmon. Conversely, focal staining, ranging from 2% to 10% of neoplastic cells, was detected in myofibroblastomas, even though it was restricted to 50% of analysed cases. CONCLUSIONS: Our results, indicating that smooth muscle differentiation occurs in a minority of the myofibroblastoma cells exclusively in half of the analysed cases, support the separation of myofibroblastoma from leiomyoma. The detection of smooth muscle cells in breast myofibroblastoma is easily explained if we postulate its histogenesis from the CD34+ fibroblasts of mammary stroma capable of multidirectional mesenchymal differentiation, including smooth muscle. We recommend retention of the term myofibroblastoma for all the desmin-positive and/or alpha-smooth muscle actin-positive spindle cell tumours of the breast consistent with the previously well-established morphological criteria for such neoplasms, unless one is dealing with a typical leiomyoma easily recognizable at light microscopy.     

Leiomyoma of the gastrointestinal tract with intracytoplasmic inclusion bodies. Report of three cases

We report three cases of leiomyoma of the gastrointestinal tract with intracytoplasmic inclusion bodies similar to those characteristic of inclusion body fibromatosis (IBF). The first two cases represent leiomyoma of the stomach: one in a 70-year-old female and the other in a 72-year-old female. In both instances inclusion bodies were present in a large amount. In the third case the leiomyoma was located in the esophagus of a 63-year-old male and inclusion bodies in this case were rare. In all three cases an immunohistochemical analysis showed positivity of the tumor cells for muscle specific actin HHF35 (MSA), alpha-smooth muscle actin (SMA), h-caldesmon and desmin. The first case showed some inclusion bodies with positivity for cytokeratin CAM 5.2 and focal weak positivity for cytokeratin 18. In the second case the inclusion bodies were positive at the periphery with antibodies directed against MSA and SMA. In the third case the inclusion bodies were immunohistochemically entirely negative. Ultrastructurally, the inclusion bodies in the first case were composed of aggregated filaments, some with entrapped cytoplasmic organels and others with finely granular dense cores.     

Comparative study of CD34, alpha-SMA and h-caldesmon expression in the stroma of gynaecomastia and male breast carcinoma

AIMS: To address the fibroblastic/myofibroblastic nature of stroma in gynaecomastia and in male breast carcinoma, the expression of CD34, alpha-smooth muscle actin (SMA) and h-caldesmon in the stromal cells was investigated by immunohistochemistry. METHODS AND RESULTS: Representative archival paraffin blocks were collected from male patients with gynaecomastia (32 cases) and mammary carcinoma (24 cases) between 1984 and 2004 and CD34, alpha-SMA and h-caldesmon were assessed immunohistochemically using a streptavidin-biotin method. Thirty cases of gynaecomastia showed a CD34+, alpha-SMA- and h-caldesmon- immunophenotype with different CD34 staining intensity in the various histological subtypes. Positivity for alpha-SMA and negativity for CD34 and h-caldesmon was found in a case of florid gynaecomastia relating to reactive fibrosis due to previous surgical intervention. Acquisition of alpha-SMA expression by stromal fibroblasts but absence of CD34 staining was identified in 22 cases of male breast carcinoma. CONCLUSIONS: The immunophenotype of periductal connective tissue stroma in gynaecomastia appears to parallel the phenotype of normal breast stroma. In male breast carcinoma the stromal cell immunophenotype is similar to that of its female counterpart showing myofibroblastic differentiation. However alpha-SMA+ and CD34- are not specific to malignancy because such findings are also encountered in reactive fibrosis.     

Cellular angiofibroma and related fibromatous lesions of the vulva: report of a series of cases with a morphological spectrum wider than previously described

AIMS: Cellular angiofibroma (CA) is a rare benign mesenchymal lesion with a predilection for the vulval region. In this report we aim to describe the clinical, pathological and immunohistochemical features of a series of vulval mesenchymal lesions, some of which have the classically described histological appearance of CA while others exhibit atypical features. We believe these lesions fall within the broad spectrum of fibromatous lesions of the vulva. METHODS AND RESULTS: Seven cases were included. Histological sections were examined and immunohistochemical staining with vimentin, desmin, alpha smooth muscle actin, h-caldesmon, S100, EMA, AE1/3, CD34, CD10, ER, PR and MIB1 was performed. The patients' ages ranged from 20 to 65 years and the lesions ranged in size from 10 to 50 mm. All lesions were well circumscribed, moderately cellular lesions and were composed of bland spindle-shaped cells set in a fibrous stroma. Many blood vessels with thick hyalinized walls were present in four cases, in one case occasional such blood vessels were present and in two cases vessels with thick hyalinized walls were not present. In five cases the vessels were at least focally dilated resulting in a haemangiopericytomatous pattern. Histological features identified in a variable numbers of cases included peripheral adipose tissue (four cases), adipose tissue within the centre of the lesion (one case), stromal mast cells (six cases), stromal lymphoid aggregates (five cases), scattered multinucleate cells (five cases), hypocellular hyalinized areas (two cases), myxoid areas (four cases) and focal areas of marked cellular atypia reminiscent of symplastic change within a uterine leiomyoma (one case). Mitotic figures were identified in four cases, all with a mitotic count of < 1 per 10 high-power fields. Immunohistochemically all neoplasms were positive with vimentin and all but one with ER and PR (PR staining was not performed in one tumour). In all cases desmin, alpha smooth muscle actin, h-caldesmon, S100 and AE1/3 were negative (h-caldesmon and AE1/3 staining were not performed in one case). Three cases were positive with CD34, one with EMA and two with CD10. All exhibited a low MIB1 proliferation index of approximately 1%. One lesion recurred locally 6 months following initial removal. CONCLUSIONS: CA is a rare benign vulval mesenchymal lesion with limited potential for local recurrence. We describe several hitherto unreported histological features which add to the morphological spectrum. Although not all lesions exhibit the classically described histological features of CA, we believe all fall within the broad spectrum of benign vulval fibromatous lesions. These cases are characterized by vimentin positivity but negative staining with smooth muscle markers which assists in excluding many of the other vulvovaginal mesenchymal lesions which enter into the differential diagnosis. The immunophenotype indicates that CA probably exhibits fibroblastic rather than myofibroblastic differentiation. These lesions are almost always positive with ER and PR, suggesting that they probably arise from the hormone receptor-positive subepithelial mesenchymal layer within the lower female genital tract.     

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.     

Glomus tumor of the stomach: a case report and review of the literature

Glomus tumor is a benign soft tissue neoplasm which commonly affects the subungual region of the fingers. But the tumors can also arise in the other sites such as the antrum of the stomach. We are reporting a case of a glomus tumor of the stomach in a 71-year-old female patient who presented with dyspepsia. The tumor was confined to the lamina muscularis propria, it consisted of round cells with small uniform nuclei, which surrounded thin walled blood vessels. Immunohistochemistry revealed the tumor to be positive for smooth muscle actin, vimentin, calponin, h-caldesmon and negative for c-KIT, S-100, CD34, CD99, synaptophysin, chromogranin, desmin and EMA. The proliferation marker Ki-67 was positive in less than 5% of tumor cell nuclei. Glomus tumors are usually benign but malignant cases have been published. Criteria for the malignant potential of gastric glomus tumors remain poorly defined.     

Immunohistochemical differentiation of leiomyocellular tumors and tumors with myogenic differentiation

The expression of alpha smooth muscle actin, muscle specific actin, desmin, h-caldesmon, and calponin was studied immunohistochemically in the following soft tissue and bone tumours and tumour-like lesions: muscle fibromatosis, inflammatory pseudotumours, chondroblastoma, enchondroma, chondrosarcoma, fibrous dysplasia, ossifying myositis, osteoblastoma, convential osteosarcoma, leiomyoma and leiomyosarcoma. Tumours and tumour-like lesions with myofibroblastic cells, osteoblasts and chondroblasts frequently exhibited intensive immunoreactivity for the muscle markers, and therefore, some of them may occasionally be confused with leiomyoma and leiomyosarcoma. Calponin does not help to differentiate various mesenchymal tumours expressing muscle markers, because it also stains intensively myofibroblasts, osteoblasts and chondroblasts. We confirmed that h-caldesmon was expressed intensely in leiomyomas and leiomyosarcomas, and never in the other tumours examined, with the exception of three chondroblastomas. The results have shown that h-caldesmon is a rather specific and sensitive marker for smooth muscle tumours, but it can also stain some actin positive myochondroblasts. It is possible that the positivity of h-caldesmon in some chondroblastomas is due to their complete myogenic transdifferentiation, and so we use the term myochondroblasts and myochondrocytes for designation of such S-100 protein, actin, and h-caldesmon positive cells.     

Uterine leiomyoma with amianthoid-like fibers

A rare case of a gynecologic type leiomyoma with amianthoid-like fibers is presented. The 6 cm tumor was found in the uterus of a 46-year-old woman. Histologically, it contained a cellular spindle cell population with numerous eosinophilic amianthoid-like fibers. The morphology closely resembled that of palisaded "amianthoid" myofibroblastoma. Immunohistochemically, the lesion showed a smooth muscle phenotype with expression of h-caldesmon, desmin, alpha smooth-muscle actin, and with negativity for CD10 and the S100 protein. The finding of amianthoid-like fibers expands the morphologic spectrum of leiomyomas. It represents one of the overlapping features between leiomyoma and palisaded myofibroblastoma.     

钙化性纤维性肿瘤的临床病理学分析

目的探讨钙化性纤维性肿瘤(calcifying fibrous tumor,CVF)的临床病理学特征、免疫表型和鉴别诊断。方法回顾性分析7例CFT的临床资料、病理学形态和免疫组化标记结果。结果患者中1例为少年,6例均为成年人,年龄14—50岁,平均37岁。5例临床表现为局部缓慢性生长的无痛性肿块,2例为术中偶然发现。肿瘤分别位于腹腔／盆腔(3例)、颈部(2例)、左腹股沟(1例)和左小腿(1例)。眼观：肿块境界清楚,卵圆形或结节状,质地坚韧。镜检：肿瘤由大量胶原化的纤维结缔组织组成,其间夹杂少量梭形细胞。特征性形态学表现为在胶原化的纤维组织间可见散在的钙化灶或砂砾小体,间质内伴有多少不等的淋巴细胞和浆细胞浸润灶,部分病例中可见生发中心形成。免疫组化标记显示,梭形细胞主要表达vimentin,不表达CD34、S-100蛋白、actin、desmin、h-caldesmon和ALK1等标记。随访6例,均无复发。结论CFT是一种不同于炎性肌纤维母细胞瘤的良性纤维母细胞性肿瘤。CFT不仅好发于儿童和青少年,也可发生于成年人。组织学上应与伴有钙化的纤维母细胞／肌纤维母细胞性病变相鉴别。     

Myxoid mesenchymal tumors of uterus: endometrial stromal and smooth muscle tumors, myxoid variant

Four myxoid variant of uterine mesenchymal tumors are reported. One was a low grade stromal sarcoma with infiltrative margins and the others were well circumscribed tumors corresponding to an endometrial stromal nodule and two leiomyomas. They were hypocellular neoplasms composed of stellated cells with an abundant Alcian Blue positive myxoid matrix. The myxoid nature of the neoplasms obscured their cellular nature and made the distinction between smooth muscle and endometrial stromal tumors difficult. Endometrial stromal tumors, showed very focal areas of small basophilic cells, characteristic of endometrial stroma. The diagnosis was based on the presence of a spiral arteriolar network, a CD10 positivity as well as the absence of h-caldesmon and desmin expression. The two myxoid leiomyomas showed more spindle cells and a desmin expression while h-caldesmon was negative and CD10 focally positive in both cases. Myxoid variant of endometrial stromal tumors does not necessarily exhibit the typical morphology of endometrial stroma. They may demonstrate morphological features of smooth muscle tumors in the uterus. Also, myxoid changes in uterin smooth muscle tumors may modify the classical immunoreactivity of smooth muscle markers in these tumors and make it difficult to distinguish between benign and malignant neoplasms. An immunohistochemical panel of antibodies including CD10, h-caldesmon and desmin may help in establishing the correct diagnosis.     

Uterine leiomyoma with massive lymphoid infiltration: case report and review of the literature

Uterine leiomyoma with massive lymphoid infiltration is a rare and unusual pathological finding. Only 13 cases have been reported in English literature. A case of uterine leiomyoma showing massive lymphoid infiltration in a 45-year-old woman is described. The tumor was relatively soft compared with usual leiomyomas. Microscopically, the tumor showed the typical features of leiomyoma with moderate to severe lymphocytic infiltrate consisting of mature lymphocytes, a few plasma cells and occasional histiocytes. This cellular infiltration was confined to the leiomyoma. Immunohistochemically, the diffusely infiltrated lymphoid cells were stained by antibodies to CD45RO, CD3 and CD8. Germinal centers were stained by antibodies to CD20 and CD79a. Some CD68+ histiocytes were seen. Lymphoid infiltration within the leiomyoma is a peculiar histological morphology, although the cause is not clear. The recognition of its distinct histological features is important to avoid possible confusion with differential diagnoses including malignant lymphoma, inflammatory pseudotumor and pyomyoma.     

Posterior choroidal leiomyoma: a rare case report and literature review

We report a literature review and detailed evaluation of a rare case of posterior choroidal leiomyoma to emphasize the importance of differentiating this from other choroidal tumors. A 30‐year‐old male presented with variable blurred vision in his right eye secondary to a choroidal tumor. Clinical examinations were performed including fundus photography, optical coherence tomography, B scans, fluorescein and indocyanine green angiography, computed tomography, and magnetic resonance imaging. Preoperative examination revealed a suspected choroidal melanoma and enucleation was performed. However, a definitive diagnosis of choroidal leiomyoma was made following postoperative pathological light microscopy and immunohistochemical studies. Published case reports were collected and the common characteristics and distinctive features were compared with the current case. Posterior choroidal leiomyoma was summarized from the literature, and beneficial information for diagnosis and treatment was obtained. In conclusion, posterior choroidal leiomyoma is rare and should be differentiated from amelanotic melanomas. Despite the benign nature, an explanation regarding the rare incidence and difficult diagnosis of posterior choroidal leiomyoma must be provided to patients, prior to enucleation or detrimental treatment.     

Diagnostic usefulness of aberrant CD22 expression in differentiating neoplastic cells of B-Cell chronic lymphoproliferative disorders from admixed benign B cells in four-color multiparameter flow cytometry

The diagnosis of B-cell chronic lymphoproliferative disorders is a great challenge when made in a background of polyclonal B cells. We studied the diagnostic usefulness of aberrant CD22 expression for differentiating neoplastic from benign B cells by 4-color flow cytometry. Of 56 cases of B-cell chronic lymphoproliferative disorders, we found that neoplastic cells showed aberrant CD22 expression in 39 (70%) of 56 cases, including chronic lymphocytic leukemia, mantle cell lymphoma, marginal zone lymphoma, hairy cell leukemia, and follicular lymphoma. In 4 cases, monoclonality was detected definitively only by evaluating the immunoglobulin light chain restriction in B cells with aberrant CD22 expression because numerous polyclonal B cells were present. Aberrant CD22 expression is a useful marker for detection of monoclonal B cells admixed with numerous benign polyclonal B cells.     

Superficial cervico-vaginal myofibroblastoma: a report of five cases

AIMS: To describe the pathological and immunohistochemical features of five cases of superficial cervico-vaginal myofibroblastoma (SCVM), a recently described mesenchymal tumour affecting middle-aged and elderly females. METHODS: The histological features of five cases of SCVM arising in four patients were reviewed including one case which recurred locally 9 years after initial excision biopsy. All cases were immunostained using the streptavidin-biotin technique using antisera to vimentin, smooth muscle actin, desmin, S100 protein, cytokeratin, h-caldesmon, calponin, CD99, CD117 (c-kit), bcl-2, oestrogen receptor and progesterone receptor. RESULTS: The patients were aged from 40 to 71 years (mean 55.2 years). The tumours were situated within the vagina (four cases) and cervix (one case) and ranged from 16 to 45 mm in greatest dimension. One patient had two separate vaginal SCVM. The tumours were characterised by uniform spindle and stellate-shaped cells separated by a collagenous or myxoid stroma. No mitotic activity was identified. Characteristically the tumours were well circumscribed and separated from the surface epithelium by a rim of normal stroma. The initial and recurrent tumours in one patient were similar except for increased stromal collagen in the recurrence. All tumours were immunoreactive for vimentin, desmin, CD34, CD99, bcl-2, calponin and hormone receptors while two tumours showed focal smooth muscle actin expression. There was no expression of S100 protein, h-caldesmon, CD117 or cytokeratin. CONCLUSIONS: SCVM appears to be a relatively distinct lesion although there is some histological and immunophenotypical overlap with other mesenchymal tumours, particularly fibroepithelial polyp, leiomyoma and solitary fibrous tumour. As local recurrence developed 9 years after intial treatment in one patient, long-term clinical follow-up would seem appropriate.     

青春期前型外阴纤维瘤临床病理学观察

目的 探讨青春期前型外阴纤维瘤(PVF)的临床病理学特征、免疫表型、诊断和鉴别诊断.方法 分析2例PVF的临床表现、病理形态和免疫表型,并复习文献.结果 1例发生于8.5岁幼女,1例发生于54岁成年女性,均以右侧大阴唇复发性肿块就诊.大体上,肿块不明显,切面呈灰白色,纤维组织样.组织学上,病变位于真皮层内,周界不清.细胞密度低,由稀疏的梭形纤维母细胞样细胞和大昔的胶原纤维样间质组成.梭形细胞无异型性,核分裂象罕见.病变向皮下组织延伸,在邻近的脂肪组织之间、血管之间或在神经周围穿插性生长,形成类似错构瘤样的结构.免疫组织化学标记显示,梭形细胞主要表达波形蛋白,部分弱阳性表达CD34,不表达α平滑肌肌动蛋白、肌特异性肌动蛋白、结蛋白、高分子钙调蛋白(h-caldesmon)、CD99、S-100蛋白、bcl-2、β-catenin、ER和PR.结论 PVF是一种好发于青春期前幼女外阴的良性间叶性病变,偶可发生于成年人.PVF可能代表了一种外阴正常间叶组织的过度增生.临床上近1/3的病例如切除不净可发生局部复发,偶可自发性消退.     

Solitary fibrous tumor of the oral cavity with a predominant leiomyomatous-like pattern: A potential diagnostic pitfall

The diagnosis of solitary fibrous tumor (SFT) is usually straightforward if the typical morphologic features, including a wide variety of growth patterns, are identified. We report the clinical, radiologic, and pathologic findings of a rare case of intraoral SFT which exhibited a predominant leiomyomatous-like appearance, closely reminiscent of a leiomyoma, at both incisional and excisional biopsy. Histologically, the tumor was composed predominantly of intersecting fascicles of eosinophilic spindle-shaped cells, variably set in a fibrous stroma. A focal hemangiopericytoma-like growth pattern with alternating hypercellular and hypocellular areas, as well as the deposition of dense keloid-type collagen, raising the suspicion of SFT, could be identified only after a careful examination of the whole tumor. Immunohistochemistry was helpful in confirming the diagnosis of SFT, revealing a diffuse staining of neoplastic cells for vimentin, CD34, bcl-2 protein, and, focally, CD99. Myogenic markers (α-smooth muscle actin, desmin, h-caldesmon) were not expressed.