Hidradenoma papilliferum (HP) is a benign adnexal neoplasm which preferentially develops in the anogenital region of women. Although the origin of HP was previously thought to be an apocrine sweat gland, recent studies have suggested that it may derive from the anogenital mammary-like gland (MLG). In this paper, we present a 43-year-old Japanese woman with hidradenoma papilliferum of the vulva. The lesion developed 7 years prior to her visit, and clinically appeared as a skin-colored cystic nodule. Histopathological examination revealed that the neoplasm was formed by the tubular structures consisting of two types of pleomorphic cells, columnar cells in the luminal layer and cuboidal cells in the basal layer. Further, the surgical specimen contained a wide, divergent, lobular ductal structure located in the vicinity of the neoplastic lesion, which was consistent with MLG.

PH. Propranolol for infantile haemangiomas: insights into the molecular mechanisms of action. Br J Dermatol 2010; 163: 269-274. 4 Chiu YE, Drolet BA, Blei F et al. Variable response to propranolol treatment of kaposiform hemangioendothelioma, tufted angioma, and Kasabach-Merritt phenomenon. Pediatr Blood Cancer 2012; 59: 934-938.Primary breast carcinoma en cuirasse derived from invasive lobular carcinoma: The first case report Dear Editor, Carcinoma en cuirasse (CEC) preferentially arises in association with the cutaneous involvement of breast carcinomas. A large percentage of cases of breast CECs are secondary (recurrent) lesions following a breast operation, while 0.6-10% of the cases are primary lesions, i.e., the first manifestation of the breast carcinoma. 1 Herein we report an unusual case of primary breast CEC and discuss the importance of E-cadherin immunohistochemistry for their histopathological classification.A 60-year-old Japanese woman with no remarkable medical history visited our hospital complaining of an unusual eruption on her right breast that slowly increased in size over 35 years. A physical examination revealed a keloid-like erythematous plaque around the right nipple (Fig. 1a). An MRI scan demonstrated an irregular mass on the right mammary gland directly extending to the overlying skin. No other neoplastic lesions were found by CT screening. The findings of the skin biopsy corresponded histologically to the "Indian file" pattern, which consists of dermal changes with a proliferation of thickened collagen bundles and infiltration of a small number of atypical neoplastic cells with linear arrangement between collagen bundles (Fig. 1b,c). Immunohistochemistry showed that the atypical cells were positive for the estrogen receptor (Fig. 1d) and (a) (b) (c) (d) (e) Figure 1. (a) Clinical picture of the eruption. Hard, thickened, irregular-shaped, keloid-like erythematous plaque, 10 9 8 cm in size, was observed around the right nipple. (b, c) Histopathology of the skin biopsy specimen taken from the keloid-like lesion revealed dermal changes marked by proliferation of thickened collagen bundles and infiltration of a small number of atypical neoplastic cells with large nuclei arranged in cords and strands between collagen bundles. (b) Low magnification (HE, 9200). (c) High magnification (HE, 9400). (d, e) Immunohistochemical examination demonstrated that the atypical cells were positive for estrogen receptor (d, 9400) but were negative for E-cadherin (e, 9400).