Archives of Medicine and Health Sciences

: 2015  |  Volume : 3  |  Issue : 1  |  Page : 94--96

Malignant proliferating trichilemmal tumor of the scalp with secondary infection in an elderly man

Saptarshi Paul, Harishchandra Badekila, Anantha Prabhu Kumble 
 Department of General Surgery, Yenepoya Medical College, Mangalore, Karnataka, India

Correspondence Address:
Dr. Saptarshi Paul
Department of General Surgery, Yenepoya Medical College, Mangalore - 575 018, Karnataka


A 65-year-old man presented with the complaints of a growth on the scalp, which ruptured spontaneously leading to bleeding and foul smelling discharge associated with severe pain. Examination revealed ulceroproliferative growth with slough and surrounding induration, infested with maggots. Histopathological examination revealed proliferating trichilemmal tumor (PTT) with secondary infection. Wide excision of the tumor was done with 1 cm margin all around it. PTT is a benign neoplasm that can rarely undergo malignant transformation thought to originate from trichilemmal cyst. Malignant PTT (MPTT) predominantly affects the scalp, eyelids, neck, and face and the treatment recommended being a wide local excision.

How to cite this article:
Paul S, Badekila H, Kumble AP. Malignant proliferating trichilemmal tumor of the scalp with secondary infection in an elderly man.Arch Med Health Sci 2015;3:94-96

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Paul S, Badekila H, Kumble AP. Malignant proliferating trichilemmal tumor of the scalp with secondary infection in an elderly man. Arch Med Health Sci [serial online] 2015 [cited 2023 Feb 6 ];3:94-96
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Full Text


Proliferating trichilemmal tumor (PTT) is a rare benign adnexal tumor of the skin with a female predilection and most commonly arises as a solitary mass on the scalp during the fourth to eighth decade of life; although other sites such as the upper extremities, back, gluteal region and vulva have been reported. Typical history is of a longstanding cystic lesion showing progressive growth over several months to years at the same site before rapid enlargement occurs. [1] Trauma and inflammation may induce a trichilemmal cyst to proliferate. [2],[5] Here we report a case of a malignant PTT (MPTT) in a 65-year-old male, which is quite rare (thorough literature search revealed only a handful of cases in males above 50 years).

 Case Report

A 65-year-old man came with the complaints of painful growth on the scalp for 4 years which burst spontaneously leading to ulceration, bleeding and foul smelling discharge. The clinical examination revealed an ulceroproliferative growth with slough and surrounding induration, infested with maggots. Maggots were removed, and an edge biopsy was done [Figure 1].{Figure 1}

Microscopically, the tumor showed stratified squamous epithelium arranged in a lobular pattern in the dermis, extending from the epidermis [Figure 2]. Abrupt keratinization was present in the center of the cell masses with palisading in the periphery [Figure 3] and [Figure 4]. Impression was PTT with secondary infection. Initially was treated with broad spectrum antibiotics and regular dressings, followed by wide excision of the tumor done with a 1 cm margin all around it. {Figure 2}{Figure 3}{Figure 4}


Cutaneous tumors derived from the isthmus region of outer root sheath of hair follicles, which show trichilemmal keratinization, are trichilemmal cysts, proliferating trichilemmal cysts and malignant proliferating trichilemmal cysts. [9] In the recent years, there has been a steady rise in the number of skin biopsy specimens submitted for histopathological examination. Ordinary benign cutaneous cysts are very common in daily practice and may comprise a wide spectrum of entities, the benign end being represented by the trichilemmal cyst. Pathological examination of trichilemmal cysts remains the gold standard for detection of cytological and architectural atypia, and should be routinely performed even when there is no suspicion of a malignant process. A possibility of inheritance of pilar cysts in an autosomal-dominant mode, linked to chromosome 3, has been reported. Clinically, these may be mistaken for squamous cell carcinoma, basal cell carcinoma, nodular melanoma or keratoacanthoma. [1],[7] Most lesions measure several centimeters in diameter, but giant tumors of up to 25 cm have been described and are characterized by trichilemmal keratinization. Wilson - Jones first described PTT in 1966 as an entity that can clinically and histologically simulate squamous cell carcinoma. Initially classified as a pseudoepitheliomatous hyperplasia, a number of other terms like proliferating epidermoid cyst, pilar tumor of the scalp, proliferating trichilemmal cyst, proliferating epidermoid cyst, giant hair matrix tumor, hydatidiform keratinous cyst, trichochlamydocarcinoma and invasive hair matrix tumor have been used. [1] Metastasis from PTTs is rare. However, a sporadic malignant variant showing an aggressive clinical course and a tendency for lymph node and distal metastasis after treatment of the primary, or during initial presentation, has been reported. [1] It has been suggested that even conventional PTT, without atypical features, is a form of squamous cell carcinoma ab initio, described by the term proliferating tricholemmal cystic squamous carcinoma. Lesions showing a rounder, less complex border and an absence of nuclear crowding with increased mitoses should be termed proliferating tricholemmal cystic acanthoma accordingly. However, this view is not shared by all authors and the criteria for malignancy are not settled. Recently, a proposal for the definition of benign and malignant variants has been made with an attempt to classify the PTT into three morphological groups according to their histological appearances. These comprise:

A benign PTT behaving in a benign manner,Low-grade MPPT is having potential for locally aggressive growth and,High-grade MPTT having metastastatic potential. [1],[9]

Features favoring benign behavior includes sharp circumscription, trichilemmal keratinization, lack of epidermal connection and low mitotic activity. Low-grade MPTT is distinguished from benign PTT by stromal invasion of the dermis and mild cytological abnormalities, whereas high-grade MPTT shows additional marked nuclear anaplasia [Figure 5]. [1],[3]{Figure 5}

Differential diagnoses include benign trichilemmal cyst, florid early phase pilomatrixoma, keratoacanthoma, and primary or metastatic squamous cell carcinoma, including cystic, verrucous, trichilemmal and spindle cell (sarcomatoid) variants. [1] Immunohistochemical demonstration of trichilemmal keratinization and reactivity with AE13, AE14 and cytokeratin 15 may help to distinguish high-grade MPTT from squamous cell carcinoma. [6] Loss of CD34 immunoreactivity also has been reported in MPTT. [1]

Simple excision is curative for benign PTT with an excellent prognosis. Local excision with a margin of normal tissue around has often been the standard treatment with no established role of additional therapeutic interventions such as radiation therapy and chemotherapy. Neo-adjuvant radiotherapy with radical surgery might be indicated for cases presenting with metastatic disease, although further study of similar aggressive tumors is necessary to establish the role of adjuvant therapy. [4] Intratumoral ethanol injection to reduce tumor mass and achieve hemostasis has been successfully tried by some authors for recurrent MPTT. [8] Bajoghli et al. [10] have tried a dual approach: Mohs micrographic surgery is utilized for a more discrete removal of malignant tissue, then DermaClose ® RC is used for wound revision, providing more effective wound closure than traditional suturing.

Malignant proliferating trichilemmal tumor has been reported in two patients with keratitis-ichthyosis-deafness syndrome and this group might warrant screening for PPT. [1]


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