小宮根 真弓

顆粒変性を来たす代表的な疾患である水疱型先天性魚鱗癬様紅皮症(BCIE)，およびVörner型掌蹠角化症(PPK)の浸潤細胞を検討した結果多数のマスト細胞を認めた。マスト細胞の走化因子であるbasic fibroblast growth factor(basic FGF)の発現を検討した結果，健常人皮膚では有棘層上層に強く発現しているのに対し，これらの疾患では基底層に発現を認めた。basic FGFは，血管および表皮細胞増殖促進作用も報告がある。これらの疾患患者で認められる著明な過角化を伴う表皮増殖，毛細血管の増生，マスト細胞浸潤は，basic FGFが誘導因子の一つである可能性が示唆された。

A 46-year-old man had a cystic mass on the right side of his scalp. Histological examination revealed a cystic dermal nodule composed of relatively circumscribed lobules of proliferating squamous epithelium, with atypical mitoses and dyskeratotic cells of invasive structure, which was diagnosed as proliferating tricholemmal cystic carcinoma (PTCC). Most of the cyst was composed of thick layers of highly proliferating, atypical, dedifferentiated epithelium (dedifferentiated part), which was attached to a highly proliferative but mildly differentiated part. A completely differentiated, tricholemmal cyst (TC)-like part was also attached to the main cyst, which supports the idea of PTCC beginning in a pre-existing TC. The dedifferentiated and mildly differentiated parts exhibited a high frequency of proliferating cell nuclear antigen (PCNA)-positive cells both in the basal and the suprabasal layers, while PCNA staining was almost negative in the TC-like part. Expression of cytokeratin (CK)10 and CK16 suggested disturbed epidermal differentiation in dedifferentiated part, while TC-like part showed well-differentiated trichilemmal epithelium and the mildly differentiated part was in the middle of these two.

Necrolytic migratory erythema (NME) is an uncommon inflammatory dermatosis with a distinctive clinical and histological appearance. It shows irregular erythema, bullae, erosion, crusts and pigmentation. While it is typically associated with glucagonoma, some cases of NME without glucagonoma have been reported. Herein, we report a case of necrolytic migratory erythema associated with malabsorption 30 years after ileocolectomy. She presented erosive erythema with scale or partly flaccid bullae on her intergluteal cleft, buttock and extremities. Her laboratory data revealed essential amino acid deficiency and a slightly decreased serum zinc level, while her plasma glucagon level was low. With diagnosis of non-glucagonoma-associated NME with malabsorption due to short-bowel syndrome, she was treated and improved by i.v. amino acid supplement. Histological findings of NME include necrotic changes of keratinocytes in the upper epidermis, proliferation of those in the lower epidermis and inflammatory cell infiltration of upper dermis. We also examined the expression pattern of epidermal keratins (K6, K10) and Ki-67, one of the markers of proliferative activity, to assess the proliferation and differentiation of keratinocytes in a NME lesion by immunostaining. The findings with these immunostainings support the characteristics of HE-staining, and suggest hyponutrition may induce changing differentiation/proliferation of keratinocytes.