|LETTER TO EDITOR
|Year : 2020 | Volume
| Issue : 1 | Page : 40-41
Malignant Proliferating Trichilemmal Tumor: A Rare Adnexal Neoplasm
Bhavya P Mohan1, V Letha1, V Anilkumar2
1 Department of Pathology, Government Medical College, Kottayam, Kerala, India
2 Department of General Surgery, Government Medical College, Kottayam, Kerala, India
|Date of Submission||21-Oct-2019|
|Date of Decision||27-Oct-2019|
|Date of Acceptance||13-Apr-2020|
|Date of Web Publication||02-Jun-2020|
Bhavya P Mohan
Departments of Pathology and 1General Surgery, Government Medical College, Kottayam, Kerala
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Mohan BP, Letha V, Anilkumar V. Malignant Proliferating Trichilemmal Tumor: A Rare Adnexal Neoplasm. Indian J Dermatopathol Diagn Dermatol 2020;7:40-1
|How to cite this URL:|
Mohan BP, Letha V, Anilkumar V. Malignant Proliferating Trichilemmal Tumor: A Rare Adnexal Neoplasm. Indian J Dermatopathol Diagn Dermatol [serial online] 2020 [cited 2021 Sep 27];7:40-1. Available from: https://www.ijdpdd.com/text.asp?2020/7/1/40/285802
Malignant proliferating trichilemmal tumor (MPTT) is a very rare adnexal neoplasm of follicular isthmus. The first sign of malignancy can be a rapid growth of a long-standing proliferating trichilemmal tumor (PTT). We present the case of a rapidly growing MPTT of scalp treated by wide surgical excision. An 85-year-old female presented with a history of a mass in the scalp of 30 years' duration which was rapidly enlarging for the past 3 months. Examination showed an ulceronodular growth of 9 cm × 8 cm over the left parietal region. A wide excision of the growth was done with a clinical diagnosis of sebaceous carcinoma/angiosarcoma [Figure 1]. Grossly, we received an irregular nodular tumor with an attached elliptical piece of hair-bearing skin. Cut section showed an irregular nodular gray-white solid growth measuring 8 cm × 6 cm × 7.5 cm with lobulations, areas of necrosis, hemorrhage, and calcification. Microscopically, dermis and subcutis showed an infiltrating neoplasm with squamoid cells arranged in lobules and nests [Figure 2]. Individual cells were markedly pleomorphic with abundant eosinophilic cytoplasm, vesicular nuclei with prominent nucleoli [Figure 3]. The center of few lobules showed keratinous material (abrupt keratinization). Mitoses were frequent, including atypical mitoses. Few foci showed cysts lined by squamous epithelium with trichilemmal keratinization. Areas of necrosis, calcification, and cholesterol clefts were noted. Immunohistochemically, tumor cells showed a high Ki-67 proliferation index and negative CD34 staining (with positive internal control) [Figure 4]. The findings were consistent with a diagnosis of MPTT.
|Figure 2: Infiltrating neoplasm in the dermis with cells arranged in lobules and nests (H and E, ×200)|
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|Figure 3: Pleomorphic tumor cells with abundant eosinophilic cytoplasm, vesicular nuclei with prominent nucleoli (H and E, ×400)|
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|Figure 4: Tumor cells showing high Ki-67 proliferation index (immunostain, ×400) and negative CD34 staining (with positive internal control) (immunostain, ×200)|
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MPTT is a rare cutaneous adnexal neoplasm of hair follicle origin with very few cases reported in literature. MPTT is thought to evolve from trichilemmal cysts (TCs) which may progress into PTT due to chronic inflammation, trauma, or irritation., The histologic hallmark of both TC and PTT is trichilemmal (abrupt) keratinization in which there is the transition of a nucleate epithelial cell into anucleate, keratinized cell without intervening granular layer. Histological features of MPTT are marked cellular pleomorphism with atypical mitoses, tumor necrosis, and infiltrating margins with invasion into adjacent structures. The term “malignant proliferating TC” was proposed by Saida et al. Majority of MPTTs occur on the scalp of elderly females, less common sites being neck, groin, ear, lip, eyelid, and chest., Very rarely, MPTT has been reported in young females. MPTT has to be differentiated from squamous cell carcinoma (SCC) and trichilemmal carcinoma (TC). Lack of a preexisting epidermal lesion such as actinic keratosis and presence of trichilemmal keratinization on histology favors a diagnosis of MPTT over SCC. TC occurs as a popular, nodular, or exophytic lesion over sun-exposed areas, with histology showing lobular pattern of clear cells, trichilemmal keratinization and pagetoid spread in the epidermis or follicular epithelium.
Immunohistochemical expression of CD 34 noticed in tumors of outer root sheath is lost in MPTT, a feature of undifferentiation. Loss of CD 34 staining and high Ki-67proliferation index by immunohistochemistry, as in this case, further support a diagnosis of MPTT.
The mainstay of treatment of MPTT is wide local excision along with 1 cm margin being the treatment of choice, except for aggressive cases that are treated with adjuvant radiotherapy/chemotherapy. In our case, complete excision was done, and there is no evidence of recurrence after 2 years of follow-up.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]