論文

Calciphylaxisは小血管を中心とした全身の動脈壁の石灰化により,虚血性の皮膚皮下組織壊死をきたす原因不明で予後不良な難治性希少疾患である.Calciphylaxisの最新治療薬としてチオ硫酸ナトリウムの経静脈投与があり,既報告例や自験例からも効果的な治療であると考えられる.本治療は一般的には安全とされるが,時に重篤になりうるアニオンギャップ開大性代謝性アシドーシスに対して注意する必要がある.定期的に血液ガスをモニターし,用量を調節することが安全使用のために重要である.本治療の有効性および安全性の検討のために,今後は前向き介入研究などの実施が望まれる.(著者抄録)

Malignant melanoma is one of the lethal malignant tumors worldwide. Previously we reported that adenylate cyclase-associated protein 2 (CAP2), which is a well-conserved actin regulator, was overexpressed in hepatocellular carcinoma; however, CAP2 expression in other clinical cancers remains unclear. The aim of the current study was to clarify the clinicopathological significance of CAP2 overexpression in malignant melanoma. Immunohistochemical analyses revealed that many melanoma cells exhibited diffuse cytoplasmic expression of CAP2, whereas no normal melanocytes showed detectable immunostaining for CAP2. A high level of CAP2 expression was seen in 14 of 50 melanomas and was significantly correlated with greater tumor thickness and nodular melanoma subtypes. In addition, a high level of CAP2 expression was associated with poor overall survival in univariate and multivariate analyses. For 13 patients, samples of primary and metastatic melanoma tissue were available: four patients exhibited higher levels of CAP2 expression in metastatic tumor compared to the primary site, whereas no patient showed lower levels of CAP2 expression in metastatic melanomas. Our findings show that CAP2 overexpression is a novel prognostic marker in malignant melanoma and that CAP2 expression seems to increase stepwise during tumor progression, suggesting the involvement of CAP2 in the aggressive behavior of malignant melanoma.

The diagnosis of soft tissue tumors is often challenging. Immunohistochemical investigation, let alone routine histopathological investigation, may not allow definitive diagnosis in some cases. To overcome such difficulties, more advanced techniques need to be adopted. Herein, we report an extremely rare 56-year-old Japanese female case of extraskeletal Ewing's sarcoma (ES), successfully diagnosed by electron microscopy (EM) using formalin-fixed sections and fluorescence in situ hybridization (FISH). The patient had a 2-year history of a tumor growing on the leg. In routine histopathology, invasive proliferation of tumor cells was observed in the dermis. Tumor cells were round and uniform with large hyperchromatic nuclei, which were positively stained for CD56, VS38c, Ki-67, MIC2 and vimentin, but not for pan-keratin AE1 + AE3, cytokeratin 20, chromogranin A, synaptophysin and neuron-specific enolase. As these findings were not conclusive to make the final diagnosis, EM specimens were prepared from formalin-fixed sections and subjected to investigation. Cell surface projections and dense core granules were detected, suggestive of either Merkel cell carcinoma or extraskeletal ES. Subsequent FISH analysis identified reciprocal translocation of the ESWR1 gene, enabling the final diagnosis of extraskeletal ES. This study provides useful information enabling the diagnosis of this uncommon soft tissue tumor.

Tissue injury promotes metastasis of several human cancers, although factors associated with wound healing that attract circulating tumor cells have remained unknown. Here, we examined the primary and metastatic lesions that appeared 1 month after trauma in a patient with acral lentiginous melanoma. The levels of mRNA for periostin (POSTN), type 1 collagen, and fibronectin were significantly increased in the metastatic lesion relative to the primary lesion. The increase of these extracellular matrix proteins at the wound site was reproduced in a mouse model of wound healing, with the upregulation of Postn mRNA persisting the longest. POSTN was expressed in the region surrounding melanoma cell nests in metastatic lesions of both wounded mice and the patient. POSTN attenuated the cell adhesion and promoted the migration of melanoma cells without affecting their proliferation in vitro. In the mouse model, the wound site as well as subcutaneously injected osteoblasts that secrete large amounts of POSTN invited the metastasis of remotely-transplanted melanoma cells on the sites. Osteoblasts with suppression of POSTN by shRNA showed a greatly reduced ability to promote such metastasis. Our results suggest that POSTN is a key factor in promoting melanoma cell metastasis to wound sites by providing a premetastatic niche.