Extensive and ulcerated malignant proliferating trichilemmal (pilar) tumour, arising from multiple, large, degenerated trichilemmal (pilar) cysts

Abstract

We report a rare case of a 61-year-old homeless man with a 15-year history of multiple trichilemmal cysts that served as a forerunner for the emergence of a malignant proliferating pilar tumour. The patient presented multiple, large, purulent, ulcerated lesions ranging from 10 to 150 mm in diameter, covering most of the scalp, with large areas superimposed by extensive myiasis infestation. The patient presented with no other major clinical findings. A CT scan showed no detectable signs of local or distant metastatic invasion. Initial supportive treatment was implemented. Given the extent of the injury, further surgical excision was considered, which required transfer to a specialised surgical centre. This social case is of educational value, as it can raise clinician awareness about the ability of trichilemmal cysts to undergo malignant transformation. Additionally, it highlights the importance of adequate social assistance structures for patients in need.

Multiple Trichilemmal Cysts of the Scalp

“…Transition of proliferative TC to trichilemmal tumor is not well defined (16). The most pronounced dedifferentiation of TC is the squamous cell carcinoma (SCC) that has developed from a TC (1,3,4,(17)(18)(19). SCC can develop both from TCs and from proliferating TC/trichilemmal tumors (5,6,17,20).…”

Malignant proliferating trichilemmal tumors arising in patients with multiple trichilemmal cysts: A case series

“…Clinically, malignant proliferating trichilemmal tumors (MPTTs) present as rapidly growing exophytic ulcerated tumors. 1 , 2 Here, we report 4 cases of MPTTs and multiple TCs in middle-aged men and women with typical and atypical localizations, along with 3 different simultaneous transformation stages in one patient, and concomitant leukonychia in another.…”

“…They typically occur on the scalp of elderly women and commonly correspond to transformation of a simple trichilemmal cyst (TC). 1 , 2 , 3 , 4 PTTs can reach sizes up to 25 cm and are most often benign, but malignant transformation is possible with the presence of local invasion, atypia, and necrosis. Clinically, malignant proliferating trichilemmal tumors (MPTTs) present as rapidly growing exophytic ulcerated tumors.…”

Folliculosebaceous neoplasms: A review of clinical and histological features

“…Malignant proliferating pilar tumors have a similar clinical presentation, though more rapid growth, larger size and ulceration is common . Locoregional and rarely distant metastases have been reported …”

“…68 Malignant proliferating pilar tumors have a similar clinical presentation, though more rapid growth, larger size and ulceration is common. [69][70][71] Locoregional and rarely distant metastases have been reported. 72 On scanning magnification, the PTT is multilobulated, with well-defined rounded borders and lacks an infiltrating pattern ( Fig.…”