cylindromas are most likely very primitive sweat gland tumors differentiating toward either the eccrine or apocrine line . multiple lesions can cover the entire scalp giving an appearance of disfiguring turban , and hence , the eponym  turban tumor  . we report a rare case of malignant cylindroma arising in a patient with a solitary lesion on the parieto - temporal region . a 59-year - old female presented with chief complaint of a rapidly growing painful mass over right parieto - temporal region . she had a history of excision of similar kind of tumor at the same site twelve years back . the lesion was exophytic , well circumscribed of 7  5  3.5 cm size . radiographic examination of the skull did not show any abnormality and magnetic resonance imaging of the brain revealed no intracranial pathology . all the laboratory investigations were within normal range . under general anesthesia , wide surgical excision of the lesion with 1.5 cm intact skin margins microscopically , majority of the histological sections revealed malignant component with irregular asymmetrical nodules and large solid sheets of tumor cells [ figure 2 ] . marked cellular pleomorphism with prominent nucleoli and mitosis up to 10 - 12/ high power field was noted [ figure 3 ] . surgical margins were free of tumor , and there was no aponeurotic invasion in any of the sections . this consisted of aggregated , multiple circumscribed islands of epithelial cells surrounded by hyaline sheaths arranged in jigsaw pattern [ figure 4 ] . gross photograph showing exophytic growth with ulcerated and irregular nodular surface photomicrograph showing malignant component with irregular asymmetrical nodules . ( h and e stain , 400 ) photomicrograph showing pleomorphism with prominent nucleoli and mitosis ( h and e stain , 400 ) photomicrograph showing histopathological pattern of cylindroma consisting of aggregated , multiple islands of epithelial cells surrounded by hyaline sheaths arranged in jigsaw pattern . ( h and e stain , 40 ) the patient had been on follow - up and at the end of 15 months postoperatively there were no local or distant metastases . all the laboratory investigations , radiological examination of chest and computerized tomography of cranium and bones are normal . ancell first described the cylindroma in 1842 and malignant change was described in 1929 by weidman . the clinical features of cutaneous cylindroma are pink , skin colored , nodular growth ; it may be solitary or multiple and vary in size from a few millimeters to centimeters . clinically , cylindroma has two types of presentations : i ) a solitary form , occurring in patients without a family history of cutaneous cylindromas and ; ii ) a variant with multiple cutaneous cylindromas , which is supposed to be inherited in an autosomal dominant manner . cylindromas are also a component of the brooke - spiegler tumor ; this is a dominantly inherited form associated with multiple facial trichoepitheliomas . malignant transformation of cutaneous cylindromas is very rare and is usually seen in multiple types . the prevalence of malignant cylindroma is not well - established since the literature largely consists of case reports and not all the cases are documented properly . using a pubmed database search , we found a total of 36 well - documented cases of malignant cylindroma in the literature . studies have reported external factors like incomplete surgical excision , radiation therapy , frequent trauma and chronic irritation to play role in histogenesis of malignancy . in the present case , clinically , malignant transformation is suggested by ulceration , rapid growth , bleeding , color change , pain and fixation of the lesion . in our patient the histological features of malignant cylindroma are prominent large cells , pleomorphic nuclei , increased abnormal mitoses , loss of jigsaw pattern , loss of hyaline sheaths and loss of peripheral palisading at the tumor island periphery . there may be metastases to regional lymph nodes , stomach , thyroid , liver , lung and bones . immunohistochemical expression of s-100 , alpha - smooth muscle actin , ema , cea , laminin , collagen iv , fibronectin and cd-34 are seen . the preferred mode of treatment for solitary lesions is wide local excision because of undesirable recurrence rates and the risk of malignant transformation of these tumors . the reported treatment modalities are simple excision , scalping , mohs micrographic surgery and laser ablation . multiple cylindromas usually require extensive plastic surgery that may be obviated by progressively excising a group of nodules in multiple sittings . malignant cylindroma arising in solitary lesion is very rare , but should be considered among clinically altered tumors . once transformation takes place , the tendency for aggressive local destruction and potential to metastasize is high .
a 59-year - old woman presented with a history of rapidly progressive recurrent tumor of 6.5 cm diameter of the scalp . 
 histopathological examination revealed a case of malignant cylindroma . 
 there has been no recurrence or metastases and the patient is disease free at the end of 15 months postoperatively . 
 malignant transformation occurs less often in solitary form of cylindroma , but once transformed , tumors behave aggressively with extensive local infiltrative growth or metastases . 
 the case is reported to document a rare case of malignant cylindroma arising in a patient with solitary cylindroma on the parieto - temporal region .