Don’t Judge a Tumor by Its Biopsy!

Abstract

Trichoblastomas (TBs) are extremely rare, benign hair germ tumors that can mimic basal cell carcinoma (BCC). They usually arise on the head or neck and have a potential for malignant transformation, albeit it is rare. We report a case of giant TB on the forehead of a 75-year-old otherwise healthy woman. Since the age of 20 she reported a bulge on her forehead, in which a superficial-looking wound had now developed. Initially a dermatologist biopsied the tumor suspecting a BCC, which the histological analyses confirmed. The patient was then referred to the Department of Plastic Surgery for complete excision of the carcinoma, including the large frontal bulge. Surprisingly, the concluding pathology report changed the diagnosis from a BCC to a TB. Current management of most skin lesions relies on the histopathological subtype of a single punch biopsy. Many benign and malignant dermatological entities may mimic BCC, and therefore misdiagnosis can lead to either unnecessary excision or delayed treatment of metastatic disease. Mimics may include various types of nonneoplastic processes, benign adnexal tumors, including TB, or cutaneous carcinomas with basaloid features. A single punch biopsy is not always adequate in making the correct diagnosis. Although it is considered the gold standard, the clinical assessment is just as important. Due to its potential for malignant transformation, it is recommended to excise TB with negative margins.

Periocular Trichoblastoma: A Diagnostic Dilemma

“…However, the term has undergone several alterations since and the collective term of “trichogenic tumors” has been proposed for benign neoplasms of hair follicles, including TBL and trichoepithelioma [ 3 , 4 ]. A diagnostic dilemma presents itself when trichogenic tumors − rare, benign epithelial tumors − and BCC − the most common malignant skin cancer − share several overlapping clinical and histological characteristics [ 2 , 5 , 6 , 7 ]. Establishing the correct diagnosis is vital in these instances as surgical treatment for each differs: BCCs require surgical resection with free margins, while TBL requires simple surgical resection [ 8 ].…”

Nodular trichoblastoma or basal cell carcinoma: A diagnostic dilemma of clinical significance

“…These tumors usually arise in the head or neck region and may undergo malignant transformation. 1,2 Because of its potential for malignant transformation; complete surgical excision with negative margins is highly recommended. Dermoscopically, clinically,and histologically sometimes it is very difficult to differentiate between BCC and TB, so in this case report we emphasize the role of various IHC markers including Ki-67/MIB-1 antibody Index at reaching definitive diagnosis so that patient can get appropriate therapy as TBs have better prognosis, lower chances of recurrence and very less likelihood of progression to malignancy.…”