Miki Izumi

Usefulness of D2-40 immunohistochemistry for differentiation between kaposiform hemangioendothelioma and tufted angioma.

Background:  Recent investigations have demonstrated the utility of the monoclonal antibody D2‐40 as a marker for lymphatic endothelium. D2‐40 can be used on formalin‐fixed and paraffin‐embedded materials. Our objective was to elucidate, using D2‐40 immunohistochemistry, the differences among capillary hemangiomas, and especially between kaposiform hemangioendothelioma (KHE) and tufted angioma (TA). We studied four cases of KHE, nine cases of TA, and 31 cases of other vascular tumors. Antibodies against CD31, CD34, factor VIII‐related antigen, and GLUT1 were also applied.

Cytoplasmic and/or nuclear staining of beta-catenin is associated with lung metastasis

Beta-catenin is involved in cell motility in the extracellular matrix, and is expressed in normal and neoplastic mesenchymal cells. In order to clarify whether beta-catenin expression in the cytoplasm and/or nucleus is associated with a propensity for pulmonary metastasis in osteosarcoma, the LM8 murine osteosarcoma cell line with a high metastatic potential to the lung was compared with original Dunn cells in terms of the beta-catenin expression level. Both osteosarcoma cell lines lost membrane localization of beta-catenin. However, beta-catenin gene had no mutation in exon 3 by direct sequence analysis. A large number of LM8 cells showed diffuse cytoplasmic and/or nuclear staining of beta-catenin (30.8 per high power field (HPF)), while a much smaller number of Dunn cells showed expression of beta-catenin (7.7 per HPF). Cells with positive staining of beta-catenin were frequently seen at the invasive front and in intravenous tumor deposits within the metastatic lesions to the lung. Thus, LM8 cells express a larger amount of the beta-catenin protein than Dunn cells, as judged by immunoblot analysis. In five resected cases of pulmonary metastasis, translocation of beta-catenin to the cytoplasm and/or nucleus of osteosarcoma cells was detected, although seven primary osteosarcomas cells that did not metastasize for more than five years did not show beta-catenin expression. These data indicate that the cytoplasmic and/or nuclear staining of beta-catenin is a biological marker of metastatic potential of osteosarcoma to the lung.

Correlation between liver metastasis of the colocalization of actin‐related protein 2 and 3 complex and WAVE2 in colorectal carcinoma

Directed movement of normal cells occurs when actin‐related protein 2 and 3 complex (Arp2/3 complex) triggers the actin polymerization that forms lamellipodia immediately after binding to WAVE2. In order to determine whether the same mechanism correlates with liver metastasis from colorectal cancer, paired mirror sections of 154 cancer specimens (29 cases with liver metastasis and 125 cases without liver metastasis in which T factor, gender, primary tumor site, and age at operation were matched) were examined immunohistochemically for the localization of Arp2 and WAVE2. Expression of both Arp2 and WAVE2 was detected in the same cancer cells in 55 (35.7%) of the 154 cases, but not detected in the normal colonic epithelial cells. Univariate analysis showed that the colocalization was significantly predictive of liver metastasis (risk ratio [RR] 8.760. Likewise, histological grade (RR 2.46), lymphatic invasion (RR 9.95), and tumor budding (RR 4.00) were significant predictors. Among these, colocalization and lymphatic invasion were shown to be independent risk factors by multivariate analysis. Another 59 colorectal specimens were examined for mRNA expression of Arp2 by real time polymerase chain reaction. High mRNA levels of Arp2, that in situ hybridization revealed to be expressed by the cancer cells, were significantly associated with liver metastasis. However, its effect was absorbed by the influence of risk of the colocalization that is closely related to high expression of Arp2. These results indicate that the colocalization of Arp2 and WAVE2 is an independent risk factor for liver metastasis of colorectal carcinoma. (Cancer Sci 2007; 98: 992–999)

Ten cases of sebaceous carcinoma arising in nevus sebaceus.

Although nevus sebaceus is known to develop various types of secondary neoplasms, it rarely causes carcinoma and only 14 cases of secondary sebaceous carcinoma have been reported. In this study, 10 cases of sebaceous carcinoma arising in nevus sebaceus were collected. The clinicopathological features and results of immunohistochemical examinations with adipophilin, perilipin and p53 were summarized. Sebaceous carcinoma arising in nevus sebaceous predominantly occurred on the scalp (8/10) of elderly women (mean age, 67.7 years). No case was associated with Muir–Torre syndrome. We found several pathological features of sebaceous carcinoma; that is, made up mainly of germinative cells, moderate nuclear atypia without pleomorphism and many mitoses (4–28/10 high‐power field). Adipophilin and perilipin antibodies highlighted lipid drops in the cytoplasm of the malignant cells in all cases. Overexpression of p53 was seen in all cases. In two cases there were coexisting benign‐looking sebaceous lesions at the periphery of the main cancer nodule, and in these lesions p53 showed low positivity compared with the clearly malignant area. There was co‐occurrence of another neoplasm in three cases with trichoblastoma, sebaceoma and syringocystadenoma papilliferum, respectively. All cases were treated by excision of the malignant lesion, with or without inclusion of the nevus sebaceus. In a follow‐up period of 1–7 years, there was no case of recurrence, lymph node metastases or distant metastases. With these specific pathological and immunohistochemical findings using adipophilin, perilipin and p53, we have to consider the possibility that there is a tendency to underdiagnose secondary sebaceous carcinomas in nevus sebaceus. These clinicopathological features of sebaceous carcinomas developing in the nevus sebaceus seem to indicate different biological entities from de novo sebaceous carcinoma.

Sebaceous carcinoma of the eyelids: Thirty cases from Japan

Sebaceous carcinoma of the eyelids is rare in Western countries but not uncommon in Asian countries. Diagnosis is difficult both clinically and histologically. Thirty cases of sebaceous carcinoma of the eyelids treated at Tokyo Medical University Hospital were reviewed to elicit characteristic features of pathological findings. The tumor cells were infiltrating in a lobular pattern that consisted mainly of large atypical germinative cells. Sebocytes seen in the lobules had conspicuous nucleolus associated with perinucleolar halo. In 17 cases (57%) there was foamy histiocyte infiltration in and around the tumor nests. Sebaceous duct differentiation, namely holocrine secretion indicating a specific type of coagulation necrosis maintaining a cellular framework or maintaining a bubbly cytoplasm associated with nuclear debris in the periphery, was seen in 24 cases (80%). Although unequivocal squamous differentiation was limited to only 11 carcinomas, scattered individual necrosis with nuclear debris in the background of germinative cells appeared in 29 cases (96.7%). Expression of epithelial membrane antigen, perilipin and adipophilin were detected in all cases. In conclusion, to detect sebaceous differentiation in sebaceous carcinoma, it would be helpful to focus on holocrine secretion, squamous differentiation and foamy macrophage infiltration, and to utilize immunohistochemistry involving anti‐perilipin and anti‐adipophilin stain.

Sebaceous Epithelial-myoepithelial Carcinoma of the Salivary Gland: Clinicopathologic and Immunohistochemical Analysis of 6 Cases of a New Histologic Variant

Epithelial-myoepithelial carcinoma (EMC) of the salivary glands is an uncommon, low-grade malignant tumor. A recent report demonstrates sebaceous differentiation in this tumor even though its significance has never been documented as a precise histologic variant. Six cases of EMC exhibiting sebaceous differentiation (sebaceous EMC) of the parotid gland were analyzed for their clinicopathologic features and immunohistochemical characteristics. In addition, primary salivary sebaceous carcinomas were also examined for comparison. In our series, the incidence of sebaceous EMC was 0.2% among 3012 cases of parotid gland tumors and 14.3% of all EMC cases. The 6 patients comprised 2 men and 4 women, age ranging from 77 to 93 years (mean, 83.7 y). Neither cervical lymph node nor distant organ metastases were found in any cases of sebaceous EMC and no patients died of disease, though local recurrences developed in 1 patient. Conversely, cervical lymph node metastasis was detected in 2 of 3 patients with sebaceous carcinoma, 1 of whom died of disease at 12 months. Histologically, all 6 tumors had an area of sebaceous differentiation admixed with features of bilayered ductal structures typical of EMC. A component of sebaceous differentiation was distributed diffusely in 4 tumors and focally in 2. Cytologic atypia of sebaceous EMCs was lesser than that of sebaceous carcinomas. Immunohistochemically, putative myoepithelial markers such as α-smooth muscle actin, calponin, p63, cytokeratin 14, S-100 protein, and vimentin were highly expressed in sebaceous EMC. However, the expression of the latter 4 markers was also observed in primary sebaceous carcinomas, whereas these tumors were all negative for α-smooth muscle actin and calponin. Positive immunoreactivity for epithelial membrane antigen, adipophilin, and perilipin confirmed sebaceous differentiation in EMC. These results indicate that sebaceous EMC is a low-grade malignancy, similar to conventional EMC. Our data also suggest that immunohistochemical examination of specific myoepithelial markers is helpful in distinguishing sebaceous EMC from sebaceous carcinoma, which may occasionally be associated with an aggressive clinical course.

Subungual melanoma: Histological examination of 50 cases from early stage to bone invasion

Subungual melanoma is a rare form of malignant melanoma. It is extremely difficult to differentiate it histologically from benign melanonychia striata or melanocytic nevus, especially in the early stage. We divided 50 cases of subungual melanoma into four groups according to clinical progress, and examined their histological findings in each respective stage. In the early stage (19 cases), atypical melanocytes were polygonal showing slight nuclear atypia with no mitoses at all. In six out of 19 cases (31.6%), the atypical melanocytes proliferated more in the hyponychium than in the nail matrix, and only very few in the nail bed. Periungual pigmentation (Hutchinsons sign) appeared from the early stage in almost all cases. With stage progression (middle stage, 13 cases; progressive stage, 13 cases; and bone invasive stage, five cases) the number of atypical melanocytes and their degree of nuclear atypia increased, and the ascent of atypical melanocytes and pagetoid spread became conspicuous. Mitoses became apparent only from the progressive stage. From these observations, we would like to propose three new pathological clues of early stage subungual melanoma: (i) “skip lesion”, proliferation of the tumor cells are more prominent in the hyponychium than in the nail bed or nail matrix; (ii) histological confirmation of Hutchinsons sign; and (iii) epithelial thickening and/or compact arrangement of the elongated basal cells.

A Case of Myxoid Adrenocortical Carcinoma With Extensive Lipomatous Metaplasia

We report a combination of unusual myxoid change and extensive lipomatous metaplasia of an adrenocortical carcinoma. The patient was a 38-year-old man with hypertension and heart failure. Radiographic examination revealed the presence of a left adrenal tumor, and adrenalectomy was performed. The tumor weighed 380 g and appeared encapsulated. The cut surface was predominantly gelatinous. Histologically, the tumor was composed of atypical round cells with eosinophilic to vacuolated cytoplasm. The tumor was diagnosed as adrenocortical carcinoma. The stroma accumulated copious mucinous material. In addition, individual to nodular mature adipocytes were admixed throughout the tumor. The transition from carcinoma cells to mature adipocytes was recognized. Myxoid change is a very rare phenomenon in adrenocortical carcinoma, and only 10 similar cases have been reported to date. Lipomatous metaplasia is another peculiar feature of adrenocortical lesions that has been reported only in benign conditions. To our knowledge, this is the first reported case of adrenocortical carcinoma with lipomatous metaplasia.

ELF4/MEF Activates MDM2 Expression and Blocks Oncogene-Induced p16 Activation To Promote Transformation

ABSTRACT Several ETS transcription factors, including ELF4/MEF, can function as oncogenes in murine cancer models and are overexpressed in human cancer. We found that Elf4/Mef activates Mdm2 expression; thus, lack of or knockdown of Elf4/Mef reduces Mdm2 levels in mouse embryonic fibroblasts (mefs), leading to enhanced p53 protein accumulation and p53-dependent senescence. Even though p53 is absent in Elf4−/− p53−/− mefs, neither oncogenic H-RasV12 nor c-myc can induce transformation of these cells. This appears to relate to the INK4a/ARF locus; both p19ARF and p16 are increased in Elf4−/− p53−/− mefs, and expression of Bmi-1 or knockdown of p16 in this context restores H-RasV12-induced transformation. Thus, ELF4/MEF promotes tumorigenesis by inhibiting both the p53 and p16/Rb pathways.

Primary seminoma of the prostate.

A 54‐year‐old gentleman was suspected of having sarcoma of the prostate because of his low serum prostate‐specific antigen level (1.9 ng/mL) and an enlarged heterogeneous mass on computed tomography and magnetic resonance imaging scans. Pathological examination of the prostate needle biopsy indicated seminoma, which was confirmed with immunohistochemical staining. There was no evidence of disease in other areas on physical examination or on radiographic tests. Therefore, we diagnosed the case as a primary seminoma of the prostate, which was consequently treated with a total of three courses of bleomycin, etoposide and cisplatin chemotherapy. Complete response was obtained on computed tomography, magnetic resonance imaging and prostate needle re‐biopsy. To our knowledge, there have only been five cases of primary seminoma of the prostate reported.