Epithelioid leiomyoma of the larynx

We describe the pathological features of a case of laryngeal epithelioid leiomyoma (leiomyoblastoma) which, to our knowledge, is the second case to be reported in the world literature. A review of the literature confirmed that leiomyoma as such is a very rare neoplasm in the larynx, and only 33 cases have been previously reported. The neoplasm was located in the left vocal cord and consisted of mainly epithelioid, round or spindle-shaped cells, often with clear cytoplasm, which were arranged predominantly in solid nests and sheets. The tumour cells showed positive immunoreactivity for smooth muscle actin and desmin. The tumour showed low mitotic activity and immunostaining with MIB 1 (Ki-67) accordingly revealed the occasional cell only to be positive, confirming a low proliferative activity in agreement with a benign neoplasm. Epithelioid leiomyomas located in other sites have been shown to act occasionally in a malignant fashion, and the necessity for careful long-term follow-up of the patient is therefore emphasized.     

子宫血管周上皮样细胞肿瘤临床病理观察

目的研究子宫血管周上皮样细胞肿瘤的病理学特征、诊断、鉴别诊断和生物学行为。方法对5例子宫血管周上皮样细胞肿瘤进行常规组织学和免疫组织化学（SP法）染色和观察,对患者进行随访,并复习相关文献。结果光镜下5例肿瘤均由透明或嗜酸细胞巢或宽窄不等的细胞索组成,间质有丰富的小血管和程度不等的透明变。免疫组织化学染色示5例瘤细胞均黑色素细胞标记阳性和程度不等的结蛋白和平滑肌肌动蛋白（SMA）阳性,CK和CD10阴性。5例患者现均存活。结论子宫血管周上皮样细胞肿瘤具有较特征性的组织病理及免疫组织化学特点,HMB45阳性对诊断有重要作用。该肿瘤分良性、恶性潜能不能确定和恶性三类,应与透明细胞癌和上皮样平滑肌肿瘤区别。     

子宫上皮样平滑肌瘤的临床病理观察

目的 探讨子宫上皮样平滑肌瘤(epithelioid leiomyoma，EL)的临床病理特征和生物学特性。方法 收集14例子宫EL的临床和病理资料。随机抽取同期l0例子宫低度恶性间质细胞肉瘤作为对照。采用二步法进行actin、Des、EMA和CDl0免疫组化染色。结果 子宫EL临床表现无特征性。镜下显示肿瘤细胞呈类似上皮细胞样的圆形、卵圆形或多边形，核呈圆形或卵圆形，胞质嗜伊红染色或部分伴空泡化改变似核周晕，也可表现为富含糖原的透明细胞。平均核分裂象0～1个10HPF。14例EL的actin、Des全部阳性表达，EMA9例阳性，CDl0有2例呈弱阳性。l0例子宫低度恶性间质细胞肉瘤actin、Des、EMA和CDl0分别有5例、3例、2例和7例阳性表达。结论 子宫EL有特殊的病理形态特征；免疫组化有助于鉴别诊断。     

So-Called Glandular Schwannoma: Ependymal Differentiation in a Case

A cervical root tumor in a patient with neurofibromatosis showed a biphasic pattern of spindle and epithelioid cells with prominent “gland” formation, characteristic of the so-called glandular schwannoma. Electron microscopy and histochemistry of the “glands” disclosed features consistent with an ependymal differentiation. It is noted that there is a curious preferential association of ependymal lesions and neurofibromatosis, the pathogenesis of which is not understood.     

A uterine leiomyosarcoma that became positive for HMB45 in the metastasis

Uterine smooth muscle tumors are usually spindle cell lesions, but a minority is composed of epithelioid cells. Foci of clear cells can be found in these latter tumors. Recently, it has been shown that some of these tumors can be positive for HMB45, and some authors have advocated calling these lesions perivascular epithelioid cell (PEC) tumors or PEComas. The case we describe here clearly shows that the so called PEC is just a smooth muscle cell capable of changing its immunophenotype. The patient involved is a 29-year-old black woman who was found to have an epithelioid leiomyosarcoma of the uterus in November 1995. She was treated with a simple hysterectomy and bilateral salpingo-oophorectomy. A metastatic lesion was found in her liver. She, therefore, also received chemotherapy and was free of disease until October 2002, when a recurrent tumor was detected in her spine. After undergoing resection of the lesion at 2 different times, in 2002 and 2003, the patient was treated with radiotherapy and is currently receiving chemotherapy. On microscopic examination, the tumor in the uterus and liver both proved to be an epithelioid leiomyosarcomas that was diffusely positive for smooth muscle actin. Approximately 15% of the cells had clear cytoplasm, but sections from 2 different blocks were completely negative for HMB45. However, although the tumors resected from the spine in 2002 and 2003 showed features similar to those of the uterine neoplasm, but with a lower percentage of cells positive for smooth muscle actin and more clear cells, several of the clear cells were positive for HMB45. To the best of our knowledge, this is the first case of a uterine smooth muscle cell tumor that became positive for HMB45 when it metastasized.     

Primary hepatic clear cell myomelanocytic tumor. Case report and review of the literature

A case of hepatic clear cell myomelanocytic tumor in a 31-year-old woman presenting clinically with abdominal pain is reported. Histopathologic examination showed a lesion characterized by a population of large epithelioid cells with clear or eosinophilic granular cytoplasm, rich in glycogen. Immunohistochemically, the tumor cells were positive for HMB-45, Melan-A and muscle-specific actin, but negative for epithelial markers, desmin, S-100 protein, and neuroendocrine markers. Ultrastructurally, the tumor cells had abundant glycogen, well-developed rough endoplasmic reticulum, microtubules and aberrant melanosomes. Clinical and pathologic features with a brief review of the relevant literature for hepatic CCMMT as a variant of perivascular epithelioid cell tumor (PEComa) are discussed.     

Cytopathology and Ultrastructure of Primary Rhabdoid Tumor of Lung

This case report presents the light microscopy, immunocytochemistry, and ultrastructure of the first unequivocal extrarenal rhabdoid tumor occurring in lung. Smears and cell blocks prepared from a fine-needle aspiration biopsy show the cyto-pathological features of this unusual neoplasm, in this case presenting in a 74-year-old male. Electron microscopy of the surgically resected circumscribed pulmonary mass assisted in establishing the diagnosis by demonstrating the considerable accumulation of cytoplasmic intermediate filaments that characterize cells in extrarenal rhabdoid tumor and account for the hyaline “inclusion” in this particular lesion.     

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.     

伴有大量淋巴样细胞浸润的子宫平滑肌瘤临床病理分析

目的探讨伴有大量淋巴样细胞浸润的子宫平滑肌瘤的临床病理学特征及诊断、鉴别诊断。方法对3例伴有大量淋巴样细胞浸润的子宫平滑肌瘤进行临床病理分析及免疫组化染色,同时复习相关文献。结果子宫平滑肌瘤间质中见到大量成熟的小淋巴细胞浸润,大部分浸润的淋巴细胞呈CD45RO、CD3和细胞毒性淋巴细胞标志物CD8及TIA-1阳性。结论伴有大量淋巴样细胞浸润的子宫平滑肌瘤是子宫平滑肌瘤的一种特殊类型,非常罕见,病理形态上要注意与淋巴瘤鉴别;在其发生学上可能与流产后体内高激素水平状态的突然消失有关。     

胃肠道间质瘤的光镜、免疫组织化学和超微结构的观察

目的 研究胃肠道间质瘤（GISTs）的光镜,电镜形态特点和免疫组织化学在诊断中的价值,探讨肿瘤的组织来源和分型。方法 对GISTs进行光镜和超微结构的观察,用EnVision二步法免疫组织化学方法检测波形蛋白,CD117（c-kit),CD34等8种抗原标记物在肿瘤中的表达情况。结果 65例GISTs占同期消化系统间叶性肿瘤的85．5％（65／76）;其中梭形细胞为主的有46例,伴有上皮样细胞的有13例,单纯由上皮样细胞组成的有6例,瘤细胞呈长,短梭形和圆形,胞质弱嗜酸,常见核端空泡,有时呈印戒样或透明细胞样;排列呈旋涡状,栅栏状或弥漫性巢状。超微结构表现出树枝样突起,神经内分泌颗粒,桥粒样连接等神经分化特点,或（和）胞质内出现密斑,密体等肌性分化。免疫组织化学显示肿瘤组织中抗原标记物表达阳性率波表蛋白为100％（65／65）,CD11793．8％（61／65）,CD3478．5％（51／65）。结论 GISTs是消化道最常见的间叶性肿瘤,光镜形态与真性肌源性和神经源性肿瘤极为相似,电镜和CD117,CD34等免疫标记物配合使用可对其做作出正确诊断,GISTs可能起源于多潜能的,卡哈尔间质细胞样的前体细胞。     

Glycogen-rich Clear Cell Carcinoma of the Urethra: An Ultrastructural Study

A 49-year-old black woman developed a urethral glycogen-rich clear cell carcinoma. She was treated with anterior pelvic exenteration. The resected lymph nodes, vagina, uterine cervix, endometrium, ovaries, and urinary bladder were free of neoplasm. Histologically the neoplasm consisted of clear cells growing in sheets and occasional papillary structures. In some areas, hobnail cells were present. Ultrastructurally, the cells had apical caps, short microvilli, and complex cell bases, and contained abundant glycogen. These features were identified in one, but not the other of two previously reported cases. Because glycogen-rich clear cell carcinomas of the lower urinary tract do not resemble ultrastructurally mesonephric remnants or carcinomas known to arise from them, these glycogen-rich clear cell carcinomas should not be called “me-sonephromas” as has been the practice.     

Ultrastructural Study of a Perineurioma

A case of soft tissue tumor in the left brachialis muscle of a 49-year-old Japanese female patient was studied by electron microscopy. The tumor was diagnosed as intramuscular myxoma by light microscopy, but electron microscopic observation revealed that the tumor almost entirely consisted of cells similar to normal perineurial cells. The tumor cells possessed long, slender cytoplasmic processes covered by well-developed but discontinuous basal laminae, clusters of pinocytotic vesicles, and infrequent intercellular junctions. Perineurial cells have also been observed in other peripheral nerve lesions: neurofibromas, nerve sheath myxomas, and localized hypertrophic neuropathies. However, the term “perineurioma” or “perineurial cell tumor” should be reserved for discrete tumorous masses that are almost entirely composed of perineurial cells without evidence of residual axons, Schwann cells, fibroblasts, or tactile corpusclelike structures. Perineurioma may represent a third category of peripheral nerve sheath tumors, ultrastruc-turally distinct from schwannomas and neurofibromas.     

Klarzelltumor der Lunge

Clear cell tumors of the lung are rare tumors composed of epithelioid HMB45 positive tumor cells. It has been proposed that clear cell tumors generate from perivascular epithelioid cells which are also found in renal angiomyolipoma. Due to its morphologic epithelioid features with clear cytoplasm the distinction from either primary or metastatic clear cell carcinoma is difficult. Usually clinical investigations do not lead to the final diagnosis so that only subsequent histological examination and immunophenotyping can establish the correct tumor classification. We describe the case of a 52 year old woman who underwent exploratory thoracotomy because of a lung mass in the right lower lobe. In frozen sections a solid trabecular tumor was diagnosed, paraffin histology and immunohistochemistry revealed a clear cell tumor of the lung. The difficulty of the correct diagnosis of the clear cell tumor of the lung in frozen sections is discussed as well as the differential diagnosis.     

The influence of different cultivating conditions on polymorphonuclear leukocyte apoptotic process in vitro, II: ultrastructural characteristics of PMN populations incubated with proteinase 3 anti-neutrophil autoantibodies

The present study shows the effects of proteinase 3 anti-neutrophil cytoplasmic autoantibodies (PR3 ANCA) on polymorphonuclear leukocytes (PMN) apoptotic processes in vitro. The results are part of a generalized morphological analysis of 3 identical experiments on the influence of different cultivating conditions on the apoptotic processes. As controls, the authors use the results on spontaneous PMN apoptosis (Guejes L, Zurgil N, Deutsch M, Gilburd B, Shoenfeld Y. Ultrastruct Pathol. 2003;27:23-32) and PMN populations incubated with normal human IgG. Interaction of PR3 ANCA with the target antigen proteinase 3 (PR3) is one of the crucial pathogenic factors in Wegener granulomatosis (systemic autoimmune vasculitis). Following 40 min and 12 h incubation, PMN populations were evaluated by light microscopy, transmission electron microscopy, and immunogold electron microscopy. Twelve-hour cultures, either control or incubated with PR3 ANCA, contained different cell forms ranging from normal cells to cells at the final stages of apoptosis. Neutrophils at the state of complete manifestation of apoptotic phenotype were analyzed and compared. Three morphologically distinct apoptotic cell lines were characteristic for all PMN populations studied, regardless of cultivating conditions. As in spontaneous apoptosis, these cell lines are code-named “first,” “second,” and “third.” The present study has shown, firstly, that in the presence of PR3 ANCA, all 3 apoptotic lines were modified or altered. Secondly, the modifications or alterations of apoptotic cell lines effected by PR3 ANCA are specific for each cell line: the “first” line is characterized by intensification and modification of activation; the “second” by vacuolized cell forms; and the “third” by pronounced lytic alterations of the nuclei, while the cytoplasm is fully identical to that of control cell lines.     

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.     

Characterization of smooth muscle components in renal angiomyolipomas: Histological and immunohistochemical comparison with renal capsular leiomyomas

The smooth muscle components of angiomyolipoma (AML) of the kidney have a wide histological and immunohistochemical spectrum. In the present study, 50 cases of AML and seven cases of renal capsular leiomyoma (RCL) were reviewed histologically and immunohistochemically, and the results compared with those of leiomyomas of soft parts. The AML cases were subclassified into 34 cases of common, 12 of leiomyomatous and four of lipomatous type. Even the common-type AML tissues showed a variety of histologic features, including lymphangiomyoma. The cytoplasm of leiomyomatous cells in AML was usually plump and eosinophilic, but sometimes clear with abundant glycogen, and an ovoid or irregular cleaved nucleus. AML cells, irrespective of whether they were epithelioid or leiomyomatous, stained positively for HMB45, S100 protein, and α-smooth muscle actin. RCL cells had histologic features identical to those of the leiomyomatous cells in AML. Moreover, the immunohistochemical profiles of the RCL cells were also identical to those of AML. These morphologic and immunohistochemical findings are different from those of smooth muscle tumors in soft parts and confirm that AML and RCL are closely related proliferative entities.     

Farber's Disease: A Fine Structural Study

A l-week-old baby boy presented with hepatosplenomegaly, coarse facial features, and cloudy corneas. A metabolic storage disease was considered and he underwent cutaneous and liver biopsy. By light microscopy the skin was normal. Kupffer cells were enlarged and had foamy cytoplasm. Ultrastructural examination of skin and liver demonstrated features compatible with Farber's disease: curvilinear and “banana” bodies, zebra-like structures, and concentric lamellar bodies. A deficiency of lysosomal acid ceramidase was subsequently demonstrated in cultured fibroblasts and in liver tissue corroborating the ultrastructural findings.     

The clear-cell variant of uterine epithelioid leiomyoma. An immunohistologic and ultrastructural study

A case of a rare uterine clear-cell epithelioid leiomyoma is presented, emphasizing immunohistologic and ultrastructural findings. The presence of actin, vimentin, desmin, muscle-specific antigen, and smooth-muscle-specific actin in tumor cells indicates a smooth-muscle origin, confirmed by electron microscopy. Numerous vacuolated mitochondria produced the cytoplasmic "clearing" on light microscopy.     

The values of intratumoral mast cell count and Ki-67 immunoreactivity index in differential diagnosis of uterine smooth muscle neoplasms

In this study, the role of the count of intratumoral mast cells was examined and compared with the proliferative activity exhibited by Ki-67 indices in the differential diagnosis of uterine smooth muscle tumors. Sixteen cases of leiomyosarcoma, nine cases of atypical leiomyoma and 16 cases of ordinary leiomyoma were included. The pathological features of the cases were determined by reviewing the archive materials including the patient records and hematoxylin-eosin-stained sections. Toluidine blue stain was used to highlight the intratumoral mast cells and they were counted in at least 40 high power fields. A standard streptavidin-biotin method was applied to the sections to highlight the Ki-67 immunoreactive tumor cell nuclei. These proliferative cells were counted in at least 10 high-power fields. Atypical leiomyomas tended to have a higher quantity of intratumoral mast cells than leiomyosarcomas and ordinary leiomyomas (P = 0.027 and P = 0.021, respectively). Leiomyosarcomas tended to have higher Ki-67 immunoreactivity rates than atypical leiomyomas, although the difference was not statistically significant (P = 0.82). We concluded that the quantity of intratumoral mast cells is useful in the differential diagnosis between leiomyosarcomas and atypical leiomyomas, while the cell proliferation rate expressed by Ki-67 immunoreactivity has a limited value.     

C-Kit-positive metastatic malignant pigmented clear-cell epithelioid tumor arising from the kidney in a child without tuberous sclerosis

We report the first pediatric case of malignant pigmented epithelioid clear-cell tumor arising from kidney; the lesion occurred in a 12-year-old girl without tuberous sclerosis. The tumor was widely metastatic to the retroperitoneum and chest, and the patient died of the disease 9 months after diagnosis, despite active chemotherapy. Pigmented epithelioid clear-cell tumor of the kidney is a rare variant of epithelioid angiomyolipoma and a member of the family of perivascular epithelioid cell tumors (PEComas). The tumor demonstrated overlapping features between clear-cell sugar tumor and epithelioid variant of angiomyolipoma. Tumor cells were positive for HMB-45 expression, negative for any evidence of muscular differentiation, and contained melanin pigment and premelanosomes in the cytoplasm. Diffuse C-Kit (CD117) positivity was identified throughout the tumor. This is the first report of C-Kit–positive malignant PEComas.