A high-grade malignancy bronchial mucoepidermoid carcinoma with features of giant cell carcinoma

A high-grade mucoepidermoid carcinoma associated with giant cell carcinoma of the bronchus was found in a 41-year-old man. Light and electron microscopic examinations showed glandular and squamous elements. The histology of the giant cell carcinoma was similar to those of previously reported giant cell carcinomas. It was assumed that the giant cell carcinoma in the present case is the result of transformation of mucoepidermoid carcinoma originating in the bronchial gland.     

MUCOEPIDERMOID CARCINOMA OF THE LIVER

An autopsy case of mucoepidermoid carcinoma of the liver associated with congenital cysts in a 78-year old man was reported. The liver weighed 1,900 g, and there was a massive tumor of 11 × 10 × 6.5 cm in the left lobe with multiple sero-mucinous cysts. Histologically, the tumor cells consisted of four types of cells: mucus-secreting cells, squamous cells, intermediate cells, and oxyphilic cells. The variety of tumor cells quite resembled that of mucoepidermoid carcinoma of the salivary gland. The sero-mucinous cysts were lined with a single layer of cuboidal or columnar cells and were not communicated with the biliary ducts. Part of the cysts with benign lining cells was in continuity with tumor cells of the intermediate type. Discussion was made on the histogenesis of hepatic mucoepidermoid carcinoma in particular emphasis on the association of the congenital cysts.     

Mucoepidermoid carcinoma of palatinal glands with exuberant foreign-body giant cell reaction

A 69-year-old man with a 0.6cm yellowish polypoid lesion in the lateral soft palate for 2 years is presented. Histological examination of the tumor revealed a small, well-differentiated, mucoepidermoid carcinoma dominated by densely packed cholesterol clefts in association with an exuberant foreign-body reaction with several giant cells. The tumor entity 'mucoepidermoid carcinoma with foreign-body giant cells' might be differentiated from 'mucoepidermoid carcinoma with an osteoclast-like giant cell stromal reaction' because differences in pathogenesis and tumor behavior are assumed.     

ANAPLASTIC CARCINOMA OF THE THYROID WITH OSTEOCLAST-LIKE GIANT CELLS

An unusual anaplastic thyroid carcinoma with osteoclast-like giant cells is reported in a 72-year-old woman. Monotonous proliferation of variously sized mononuclear tumor cells interspersed with numerous osteoclast-like multinucleated giant cells was dominant. A small area of papillary carcinoma merging with the anaplastic carcinoma was disclosed. Immunohistochemically, tumor cells forming papillary pattern were positive for both thyroglobulin and keratin. Cells and cell clusters positive for keratin were found in anaplastic carcinoma. Electron microscopically, the anaplastic carcinoma cells displayed prominent mitochondria, a rough endoplasmic reticulum, and intermediate cell junctions. The cell clusters formed irregular lumina into which numerous microvilli were extended and which contained colloid-like material. Occasionally incomplete basal laminae were present. Cell clusters showing transitional pictures from cell clusters to multinucleated giant cells and multinucleated giant cells engulfing mononuclear tumor cells were observed by both light and electron microscopy. Findings from this study support the conclusion that anaplastic tumor cells arise in preexisting differentiated thyroid cancer and that associated multinucleated giant cells are formed by the fusion of carcinoma cells.     

CARCINOMA WITH SIGNET RING CELLS OF THE ESOPHAGUS

A 55-year-old man with carcinoma with signet ring cells of the esophagus is described. The results of morphological examination are presented, and the classification and histogenesis of this rare tumor are discussed. Morphological examinations revealed this tumor to be composed of squamous, mucous-positive and signet ring cells. The signet ring cell had an intracyto-plastic microcyst and bundles of tonofllaments. These findings suggested that the signet ring cell was an intermediate form of squamous and adenocarcinoma cells. The findings for these three components indicated that the tumor was a kind of mucoepidermoid carcinoma. Histological findings suggested this tumor's development originated from the esophageal mucosal epithelium.     

ANAPLASTIC CARCINOMA OF THE THYROID GLAND An Ultrastructural Study on Four Cases

Four cases of anaplastic carcinoma of the thyroid, composed of one small cell carcinoma and three giant cell carcinomas, were studied with electron microscope. In the case of small cell carcinoma, fine cytoplasmic interdigitations and junctional complex between apposing cytoplasmic membranes of neighbouring tumor cells and a few microlumina within tumor cell clusters surrounded by well-defined basal lamina were seen. In the cases of giant cell carcinoma, occasional cytoplasmic interdigitations as well as desmosomal structures were detected even in tumor cells markedly pleomorphic and anaplastic. Abundant cytoplasmic organelles including profiles of Golgi apparatus, rough endoplasmic reticulum and a few mitochondria were seen in the cytoplasm of tumor cell of all four cases. Of interest to note was that all giant cell carcinomas demonstrated evidences of fairly well differentiated tumor within anaplastic carcinoma, indicating probable pre-existing either benign or malignant epithelial neoplasm more differentiated, with its subsequent anaplastic trasformation. Findings in the present study support an assumption that these anaplastic tumors are derived from the follicular epithelium of the thyroid gland. In addition, it can be said that tumor cells of the small cell carcinoma provide evidences suggesting functional differentiation of carcinoma cells to a certain extent, yet unable to produce thyroglobulin.     

UNDIFFERENTIATED CARCINOMA OF THE THYROID GLAND WITH OSTEOCLAST-LIKE GIANT CELLS

Three cases of undifferentiated carcinoma of the thyroid gland with osteoclast-like giant cells resembling those of giant-cell tumor of bone are presented. The clinical and morphologic characteristics of these cases are described and the literature concerning these tumors is reviewed. The lesions occur in elderly people, grow rapidly and are fatal, as do the usual undifferentiated carcinomas of the thyroid gland. Nevertheless, the tumors differ histologically from the usual undifferentiated carcinoma of giant cell or spindle cell type in having the osteoclast-like giant cells with many, small, uniform, benign appearing nuclei. All three tumors contained partial areas of moderately to well differentiated carcinoma; papillary carcinoma in two, and follicular carcinoma in one. Although the histogenesis of the osteoclast-like multinucleated giant cells is not definitely established, it is proposed that the giant cells are reactive in nature and histiocytic in origin because of their benign appearance, phagocytic activity, high level of acid-phosphatase activity, and some ultrastructural features and that they are formed by fusion of mononucleated histiocytes.     

Mucoepidermoid carcinoma arising in Warthin's tumor of the parotid gland

Malignant transformation of Warthin's tumor is extremely rare, although it is the second most common benign tumor of the parotid gland. We describe our experience of mucoepidermoid carcinoma arising in Warthin's tumor of the parotid gland in a 64-year-old man. He had a swelling in the left parotid-masseteric region. The removed tumor was well encapsulated and histopathologically comprised Warthin's tumor and low-grade mucoepidermoid carcinoma. The mucoepidermoid carcinoma infiltrated lymphoid stroma of the Warthin's tumor, but capsular invasion is not found. Considering the clinical course and physical examination, the lesion was diagnosed as mucoepidermoid carcinoma arising in Warthin's tumor because its features filled the criteria of malignant transformation of Warthin's tumor. There has been no recurrence or distant metastasis for 19 months. Histological change from Warthin's tumor to mucoepidermoid carcinoma may be implicated in squamous or goblet cell metaplasia of epithelial cells. It is considered that the neoplastic cells of Warthin's tumor acquire malignant genotypes simultaneously with this dual differentiation.     

Thyroid sclerosing mucoepidermoid carcinoma with eosinophilia: mimic of Hodgkin disease in nodal metastases

We present the clinical and pathologic findings of a case of sclerosing mucoepidermoid carcinoma with eosinophilia of the thyroid in a 39-year-old woman. This particular case is notable because it initially presented as a cervical lymph node metastasis, and the initial clinical and histologic impression was Hodgkin disease, nodular sclerosis type. Sclerosing mucoepidermoid carcinoma with eosinophilia is a differentiated malignant neoplasm of the thyroid that can be confused with anaplastic carcinoma, medullary carcinoma, squamous cell carcinoma, or, as in this case, Hodgkin disease. A correct diagnosis of sclerosing mucoepidermoid carcinoma with eosinophilia involves awareness of this entity and appropriate immunohistochemical analysis. In this article, we briefly review the literature and stress the histologic and cytologic findings characteristic of sclerosing mucoepidermoid with eosinophilia of the thyroid.     

ELECTRON MICROSCOPIC STUDY OF MUCOEPIDERMOID CARCINOMA IN THE PANCREAS

An autopsy case of extremely rare mucoepidermoid carcinoma of the pancreas in a 58-year-old male was reported. The main tumor in the pancreatic tail associated with wide-spreading metastases, was histologically composed of squamous cancer cell nests Intermingled with mucin-containing cells, but not true glandular structures except for metastatic foci in the liver. Electron microscopic findings of the main tumor revealed roughly three kinds of cancer cells, namely undifferentiated cells, squamous cells, and squamous cells with mucin-containing intracytoplasmic lumina, accompanied by variety of transitional forms. The mucin was similar to that of the intra-or interlobular duct epithelium of pancreas in mucin stains. Immunohistochemically, positive immune reaction of the cancer cells was observed by anti-keratin, -epithelial membrane antigen and -carcinoembryonic antigen sera. These findings suggested that the cancer cells originated from undifferentiated cells of pancreatic duct, which showed multipotency to differentiate predominantly into squamous cells, but also into mucin-producing cells. ACTA PATHOL. JPN. 37:1175–1182, 1987.     

Sclerosing mucoepidermoid carcinoma with eosinophilia of the salivary glands

We encountered two cases of low malignant mucoepidermoid carcinoma with scanty cellular atypism which originated in the parotid or submandibular gland and was characterized by marked fibrosis and eosinophilic infiltration within tumor tissue despite the predominance of the squamous component. Here we report these two cases and provide a review of the literature. We believe that clinically these two tumors with stromal fibrosis and eosinophilic infiltration have a low malignant potential, although histological examination revealed a scanty mucus-producing epithelial component. Therefore, we consider this type of tumor as a new subtype of mucoepidermoid carcinoma. A low-malignant mucoepidermoid carcinoma with stromal fibrosis and eosinophilic infiltration, as described in these two cases, may be misdiagnosed as a highly malignant mucoepidermoid carcinoma or squamous cell carcinoma because of its histologically scanty mucus-producing epithelial component. The objective of this study was to clarify their differences and to discuss the rendering of an accurate histological diagnosis, the degree of malignancy in relation to prognosis prediction, and the choice of therapy. In addition, we propose regarding this type of tumor as a new subtype of mucoepidermoid carcinoma.     

颈部淋巴结黏液表皮样癌

目的 探讨颈部淋巴结黏液表皮样癌的临床病理特点及鉴别诊断.方法 对1例颈部淋巴结黏液表皮样癌的临床病理特点进行分析并复习文献.结果 患者3次入院手术病理检查组织形态有较大变化.第一次活检标本镜下见淋巴结包膜完整,结内肿瘤组织主要由3种细胞构成:黏液细胞、中间型细胞及表皮样细胞,并可见较多含黏液的囊腔结构.第二次见肿瘤仍位于淋巴结内,主要由表皮样细胞构成,偶见分泌黏液的细胞,含黏液的囊腔结构几乎全部消失.第三次活检标本见横纹肌内浸润的癌细胞巢主要由表皮样细胞构成.随访2年,未见其他部位肿瘤.结论 (1)颈部淋巴结可能会发生原发性的涎腺黏液表皮样癌.(2)颈部淋巴结的黏液表皮样癌可反复复发并发生结外浸润.(3)随着病变进展和(或)复发,黏液表皮样癌的分化程度会逐渐降低,组织病理学形态会发生相应改变.     

UNDIFFERENTIATED CARCINOMA OF THE PAROTID GLAND WITH BIZARRE GIANT CELLS

A rare autopsy case of undifferentiated carcinoma of the parotid gland with bizarre giant cells is reported. Grossly, the tumor was fist-sized, firm, solid, grayish-white in color, and was not encapsulated, with a bean-sized ulceration on the skin. Microscopical examination revealed undifferentiated carcinoma of the parotid gland composed of bizarre giant cells, large tumor cells, and spindle cells in part. Ultrastructural examination, recovered from formalin-fixed material, disclosed filamentous structure in some large tumor cells. It is strongly suggested that myoepithelial cells played an important role in the development of the undifferentiated carcinoma of the parotid gland. The clinical and histopathological characteristics of this case is described, and the literature concerning undifferentiated carcinoma of the parotid gland is reviewed.     

Mucoepidermoid carcinoma arising in the glans penis

Mixed carcinoma (squamous and glandular) of the penis is a rare neoplasm with an unknown origin and a poorly defined prognosis. The mucoepidermoid carcinoma described herein has not been previously reported to our knowledge. The present carcinoma arose from and extensively ulcerated the squamous epithelium of the glans penis, including that surrounding the urethral meatus. The neoplasm was composed of well-differentiated nonkeratinizing squamous cell carcinoma associated with large areas of carcinoma formed by cell nests that contained poorly differentiated squamous elements and large eosinophilic to pale granular cells. Mucin stains revealed approximately one quarter of the pale cells contained mucous substances. These findings are virtually identical to the mucoepidermoid type of carcinoma seen in the cervix. The 3 previously reported cases of adenosquamous carcinoma of the penis demonstrated a relatively indolent course, with only one being associated with a single inguinal lymph node metastasis. That patient was alive and well 9 years following diagnosis. Our example of mucoepidermoid carcinoma appears to demonstrate a more aggressive course than those reported previously.     

层粘连蛋白受体单克隆抗体对人肺癌细胞生长状态的影响

观察了层粘连蛋白受体单克隆抗体对高转移能力的人肺巨细胞癌系体外培养细胞生长状态的影响。结果显示ＭｃＢ１能明显降低ＰＧ瘤细胞的生长速度。提示肿瘤细胞体外生长的调控与层粘连蛋白（ＬＮ）及层粘连蛋白受体（ＬＮ－Ｒ）的作用密切相关。     

Clear cell mucoepidermoid carcinoma of the parotid gland: a case report

Clear cell variant of mucoepidermoid carcinoma of the salivary glands is rare. A 55-year-old male patient with recently growing left parotid mass underwent superficial parotidectomy. Although the dominant component of the tumor was composed of clear cells, mucin containing cells were also present. Histochemically, alcian blue stain supported intracellular mucin positivity. Immunohistochemically, p63 was positive. Based on the morphological, histochemical and immunohistochemical findings, the case was diagnosed as mucoepidermoid carcinoma, clear cell variant.     

Comparative histogenesis and morphogenesis of mucoepidermoid carcinoma and pleomorphic adenoma

Summary Current classifications of salivary gland tumors separate mucoepidermoid carcinoma from other neoplasms on the basis of a number of histological features, in particular the lack of participation of neoplastic myoepithelial cells. However, ultrastructural examination of low- and intermediate-grade mucoepidermoid carcinomas and pleomorphic adenomas reveals many common organizational and cellular features. Of prime importance is the relationship of intermediate cells to the luminal cells in mucoepidermoid carcinomas, which is remarkably similar to that seen between modified myoepithelial cells and luminal cells in pleomorphic adenomas. The results suggest that intermediate cells of mucoepidermoid carcinoma are the counterpart of the modified myoepithelial cells of pleomorphic adenoma. The generally accepted hypothesis that the former tumor develops from an excretory duct reserve cell, while the latter originates from an intercalated duct stem cell does not seem to be valid; pleomorphic adenoma and mucoepidermoid carcinoma appear to be closely related morphologically.     

Nucleolar organizer regions in malignant salivary gland tumors.

Proliferative activity of carcinomas arising from salivary glands was analyzed by enumeration of argyrophilic nucleolar organizer regions (AgNORs). The mean numbers of AgNORs in the various tumors were as follows: mucoepidermoid carcinoma, 2.20; acinic cell carcinoma, 2.51; adenoid cystic carcinoma (ACC), 2.57; carcinoma in pleomorphic adenoma, 1.00 (benign component) and 3.99 (cancer-bearing area); salivary duct carcinoma, 4.49; polymorphous low-grade adenocarcinoma, 3.37; sebaceous carcinoma, 2.57; oncocytic carcinoma, 4.63; adenocarcinoma, 4.53. Cells of most tumors showed heterogeneous activity within the same tumor. In mucoepidermoid carcinoma, the mucous cells had suppressed activity in comparison with the epidermoid cells and intermediate cells. In ACC, the activity of the tumor cells increased according to growth pattern in the order tubular, glandular and solid. In carcinoma in pleomorphic adenoma, vigorous proliferative activity was observed in the malignant component, whereas less active cells were seen in the myxoid or chondroid matrix. AgNOR staining was useful for distinguishing benign from malignant regions in carcinoma in pleomorphic adenoma. Our results suggest that mucoepidermoid carcinoma, acinic cell carcinoma and ACC, except for that with a solid growth pattern, may be considered as low-grade malignancies, whereas solid-type ACC, the cancer component in carcinoma in pleomorphic adenoma and some of the other carcinomas have high-grade malignant behavior.     

Primary undifferentiated small cell carcinoma of the esophagus

We histologically examined undifferentiated small cell carcinoma of the esophagus from 21 patients and used immunohistochemical methods for detection of chromogranin A and p53, bcl-2, and Rb oncoproteins. Nine (43%) of the 21 carcinomas consisted solely of undifferentiated cells, but heterogeneous components of in situ or invasive squamous cell carcinoma or mucoepidermoid carcinoma were observed in the other 12 (57%) tumors. Squamous cell carcinoma in situ was observed in the mucosa adjacent to the main tumor in 7 (50%) of the 14 resected esophageal specimens. An admixture of invasive squamous cell carcinoma and undifferentiated carcinoma was observed in 4 (19%) of the 21 tumors, and mucoepidermoid carcinoma was noted in one case. Chromogranin A staining yielded a positive reaction in two (10%) undifferentiated components but was negative in all heterogeneous components. Multiple sites of p53 immunopositivity were seen in the undifferentiated component of 17 (81%) of the 21 tumors, as well as in the in situ or invasive squamous cell carcinoma or mucoepidermoid carcinoma components of 9 (75%) of 12 tumors. Seven (33%) of the 21 tumors showed positive bcl-2 immunoreactivity in the small cell component, but all of the heterogeneous components were negative. Rb protein immunoreactivity was observed in the small cell component of one (5%) case and in 9 (75%) of the 12 heterogeneous components. Six (86%) of the seven in situ squamous cell carcinoma components were positive for Rb protein. Eighteen (86%) of the 21 patients died within 24 months of diagnosis. Two patients (10%) who survived for more than 24 months had received chemotherapy.