malignant nodular hidradenoma ( mhn ) was first reported as clear cell eccrine carcinoma by keasbey and hadley in 1954 . several synonyms have been described in the literature , like malignant clear cell myoepithelioma , malignant acrospiroma , clear cell hidradenocarcinoma , clear cell eccrine carcinoma , clear cell hidradenoma , solid - cystic hidradenoma and eccrine acrospiroma . a 14-year - old female patient presented with four year history of progressively increasing swelling of the scalp . at first presentation the swelling was small and appeared as lytic lesion on ct scan [ figure 1 ] . curettage was done at first time , partial craniectomy second time , and total excision the third time . the duration between first and the second surgery was six months , and between second and third surgery was one year . the tumor cells were positive for cd99 ( membrane positivity ) and negative for cytokeratin , desmin , leucocyte common antigen , chromogranin and synaptophysin . the surgical margin was found free from tumor third time . following the third surgery the patient underwent external beam radiotherapy , 45 gy in 25 fractions . ct scan showed a large scalp lesion with streaks of calcification , and brain parenchymal invasion . a surface shaded display reconstruction of ct scan showed sunburst appearance from parietal bone . at this time parents of ( a ) ct scan at initial presentation showing a lytic lesion in parietal region ( b ) latest clinical photograph showing a massive parietal scalp swelling ( c ) latest ct scan showing scalp tumor with calcification and brain parenchymal invasion ( d ) latest ct scan of head with surface shaded display reconstruction showing tumor involving parietal bone and calcification appearing as sunburst pattern histopathology of tumor resected at time of last recurrence . hematoxylin and eosin stain ( a ) tumor cells in nodules infiltrating the superficial dermis with comedonecrosis ( * ) . 200 a 45-year - old female patient had swelling in the left parietal region for three months for which she underwent local excision elsewhere . within one and a half month the swelling reappeared , and progressed rapidly in next two months . at arrival to our institute she had a large swelling in the left parietal region . ct and mri scan of the head showed a large scalp swelling causing the bone destruction with intracranial extension [ figure 3 ] . ( a ) mri showing parietal scalp tumor with brain invasion ( b ) ct scan showing parietal scalp tumor with bone destruction a 14-year - old female patient presented with four year history of progressively increasing swelling of the scalp . at first presentation the swelling was small and appeared as lytic lesion on ct scan [ figure 1 ] . curettage was done at first time , partial craniectomy second time , and total excision the third time . the duration between first and the second surgery was six months , and between second and third surgery was one year . the tumor cells were positive for cd99 ( membrane positivity ) and negative for cytokeratin , desmin , leucocyte common antigen , chromogranin and synaptophysin . the surgical margin was found free from tumor third time . following the third surgery the patient underwent external beam radiotherapy , 45 gy in 25 fractions . ct scan showed a large scalp lesion with streaks of calcification , and brain parenchymal invasion . a surface shaded display reconstruction of ct scan showed sunburst appearance from parietal bone . at this time parents of ( a ) ct scan at initial presentation showing a lytic lesion in parietal region ( b ) latest clinical photograph showing a massive parietal scalp swelling ( c ) latest ct scan showing scalp tumor with calcification and brain parenchymal invasion ( d ) latest ct scan of head with surface shaded display reconstruction showing tumor involving parietal bone and calcification appearing as sunburst pattern histopathology of tumor resected at time of last recurrence . hematoxylin and eosin stain ( a ) tumor cells in nodules infiltrating the superficial dermis with comedonecrosis ( * ) . a 45-year - old female patient had swelling in the left parietal region for three months for which she underwent local excision elsewhere . within one and a half month the swelling reappeared , and progressed rapidly in next two months . at arrival to our institute she had a large swelling in the left parietal region . ct and mri scan of the head showed a large scalp swelling causing the bone destruction with intracranial extension [ figure 3 ] . ( a ) mri showing parietal scalp tumor with brain invasion ( b ) ct scan showing parietal scalp tumor with bone destruction eccrine glands are present throughout the skin but are most abundant in the palms , soles , and axillae . apocrine glands are found in relatively fewer regions of the body , mainly the axillae , around the nipples , the anogenital region , and occasionally a small number on the abdomen and chest . the mnh is an uncommon malignant cutaneous adnexal tumor that can show differentiation toward various components of eccrine sweat glands . it is difficult to estimate the incidence and exact number of cases reported , as mnh is described by varied names in the literature . establishing histopathologic criteria of malignancy for these tumors can be difficult because nuclear anaplasia may be absent , slight , or moderate . the mnh displays an infiltrative or invasive pattern , atypical mitosis , necrosis and angiolymphatic invasion . there are nodular or lobulated architecture of clear cells with glycogen containing cytoplasm and tubular or ductal structures . there may be a large or small representation of cells showing squamoid differentiation . however a diversity of cell types , such as polygonal cells , clear cells and spindle cells may be seen . a detailed immunohistochemical study of a series of mnh was performed to establish criteria of mnh . no consistent pattern was observed when neoplasms were stained with antibodies to carcinoembryonic antigen , s100 protein , gross cystic disease fluid protein 15 , epithelial membrane antigen , bcl1 , or bcl2 . all tumors stained positively for keratin ae1/3 and cytokeratin 5/6 , whereas ki-67 and p53 staining was strongly positive in 5 of the 6 cases ( 83% ) . in addition , it may not be necessary to segregate hidradenocarcinomas into eccrine and apocrine categories . even after the complete excision mnh have potential for uncontrollable local recurrence , tend to metastasize , and often cause death . about 50 - 60% patients present with local recurrence or metastasis despite complete removal . in a report of seven cases , six patients died within 15 - 45 months of diagnosis . wide surgical excision of the tumor with a least 2 cm of clear margins for both primary disease and local recurrences is the treatment of choice . the role of sentinel lymph node biopsy in the treatment of malignant hidradenoma is controversial . radiotherapy may also be considered though its role needs to be substantiated further . as early recurrence
malignant nodular hidradenoma ( mnh ) is a rare tumor of sweat gland known by many names in the literature . 
 scalp is a known and yet uncommon site of occurrence . 
 we describe two patients with scalp mnh with brain parenchymal invasion . 
 both tumors recurred in spite of total excision and radiotherapy .