The management of solitary trichoepithelioma versus basal cell carcinoma

Enemy in disguise: A case report of solitary trichoepithelioma initially diagnosed as BCC

INTRODUCTION

Solitary trichoepitheliomas (TE) are benign tumors that are strikingly similar to their malignant counterpart, basal cell carcinoma (BCC).

PRESENTATION OF CASE

An 83-year-old man presented with a 10-year history of a right lower lid skin mass initially diagnosed as BCC. Intraoperatively, an excisional biopsy was performed with primary reconstruction of the skin defect and the specimen was submitted for histopathology processing. Eventually, histopathology findings suggested the diagnosis of benign hair follicle tumor. The postoperative results were aesthetically pleasing and the integrity of the lower lid was preserved.

DISCUSSION

Despite being rare, benign solitary TE are frequently misdiagnosed as malignant BCC, and vice versa. Oculoplastic surgeons face considerable difficulty distinguishing the two pathologies due to their similar clinical and histological pictures. Hence, excisional biopsy should be considered whenever such discrepancy is confronted to avoid the possibility of recurrence or malignant transformation. Furthermore, immunohistochemical staining could increase the accuracy of diagnosis in such unequivocal findings.

CONCLUSION

Correlation of clinical, dermoscopic and histopathological findings are essential to establish an accurate diagnosis and select the appropriate management. In-depth understanding of eyelid reconstruction principles is mandatory to achieve desirable goals.

CD10, TDAG51, CK20, AR, INSM1, and Nestin Expression in the Differential Diagnosis of Trichoblastoma and Basal Cell Carcinoma

BACKGROUND

Trichoblastoma (TB) and basal cell carcinoma (BCC) are 2 different neoplasms composed of basaloid cells and have overlapping histopathological features. We compared the immunoexpression of CD10, T-cell death-associated gene 51 (TDAG51), cytokeratin 20 (CK20), androgen receptor (AR), insulinoma-associated protein 1 (INSM1), and nestin for the differential diagnosis of these tumors.

MATERIALS AND METHODS

We assessed a total of 27 BCC and 27 TB cases, including 4 TB lesions in nevus sebaceous and 3 malignant TB lesions for CD10, TDAG51, CK20, AR, INSM1, and nestin expression.

RESULTS

Staining for CK20, TDAG51, INSM1, and stromal CD10 was significantly more common in TB cases than in BCC cases ( P < .001). Epithelial CD10 and AR staining was significantly more common in BCC cases than in TB cases ( P < .001). The difference between the groups for nestin staining was not significant ( P > .05). Stromal CD10 staining was the most sensitive marker (96.3%) and INSM1 the least sensitive (55.6%) marker for TB. TDAG51 showed 100% specificity for TB. A larger number of CK20 positive cells was found in the cases associated with nevus sebaceous than in the other TBs.

CONCLUSION

All the selected markers except nestin were useful for the differential diagnosis between TB and BCC. CD10 and TDAG51 were more useful than the other markers. The use of CK20 could be preferred in nevus sebaceous lesions. INSM1 was less effective in highlighting Merkel cells within the lesion than CK20.

Differential diagnostic significance of epithelial and stromal CD10 expression in tumors of trichogenic origin

BACKGROUND AND OBJECTIVES

The histological differential diagnosis between benign trichogenic skin tumors and basal cell carcinoma may be challenging. We therefore set out to investigate whether expression of CD10, a cell surface protein with neutral endopeptidase activity, might be a suitable marker for the histological differential diagnosis of trichogenic skin tumors.

PATIENTS AND METHODS

We immunohistochemically analyzed 119 cases of benign trichogenic skin tumors and basal cell carcinoma. These included 28 nodular and 15 sclerosing basal cell carcinomas, 21 Pinkus tumors, 20 trichoblastomas, nine trichofolliculomas, eleven trichoepitheliomas, five desmoplastic trichoepitheliomas, and ten seborrheic keratoses.

RESULTS

The majority of nodular basal cell carcinomas expressed CD10 in tumor cells at the peripheral (22/28 [75 %]). On the other hand, trichoblastomas revealed peripheral CD10 expression in only 10 % (2/20) of cases, whereas 50 % showed central expression (10/20). Peripheral epithelial expression of CD10 was also found in Pinkus tumors (9/21 [42.9 %]) and trichoepithelioma (4/11 [36.4 %]). Desmoplastic trichoepithelioma showed no tumoral CD10 expression at all (0/5 [0 %]), while the majority of sclerosing basal cell carcinomas was positive for CD10 (13/15 [86.7 %]).

CONCLUSIONS

Our findings suggest that epithelial expression of CD10 - and not peritumoral stromal CD10 expression, as has been postulated - may well be of differential diagnostic significance. The pattern of distribution of CD10-positive neoplastic cells in particular can be useful in the diagnosis of trichogenic tumors.

Solitary Trichoepithelioma of the Eyelid: A Clinico-Pathological Correlation

Solitary trichoepithelioma of the eyelid is a very rare tumor, which needs to be differentiated from basaloid epithelioma and basal cell carcinoma. Diagnosis is based on clinical and histopathological examination. We present a case of an eyelid trichoepithelioma presenting as a long standing nodule with associated dermatochalasis. Although rare, this entity should be kept in the differential diagnosis of chronic, firm, nodular eyelid lesions.

Periocular cutaneous malignancies: a review of the literature

BACKGROUND

The periocular skin is susceptible to numerous benign and malignant neoplasms. Periocular malignancies may present differently, behave more aggressively, and pose greater challenges for treatment and repair than malignancies at other cutaneous sites. Between 5% and 10% of cutaneous malignancies occur periorbitally, with basal cell carcinoma reported as the most common malignant periocular tumor, followed by squamous cell carcinoma, sebaceous gland carcinoma, cutaneous melanoma, Merkel cell carcinoma, and other rare tumors.

OBJECTIVE

To review the current literature on cutaneous malignancies of the periocular region pertaining to etiology, incidence, clinical presentation, differential diagnosis, complications, and treatment options.

MATERIALS AND METHODS

An extensive literature review was conducted using PubMed, searching for articles on periocular and periorbital cutaneous malignancies.

CONCLUSIONS

Timely diagnosis and management of periocular malignancies is essential because of their proximity to and potential to invade vital structures such as the orbit, sinuses, and brain. Surgical excision remains the standard of care for the majority of periorbital malignancies, but given the sensitive anatomic location, tissue-sparing techniques with margin control such as Mohs micrographic surgery are the preferred method for most nonmelanoma skin cancers. Depending on tumor type, other treatment modalities may include radiation, chemotherapy, cryosurgery, topical medications, and photodynamic therapy.

Congenital solitary eyelid trichoepithelioma

Trichoepitheliomas are unusual, benign tumors of hair follicle origin. They may present in children and adults as acquired lesions on the body and face, but they rarely involve the eyelids. Solitary trichoepitheliomas have not previously been reported in infants. We present a first report of congenital solitary eyelid trichoepithelioma in an infant and review the classification of trichoepitheliomas.

Bcl-2 and CD10 expression in the differential diagnosis of trichoblastoma, basal cell carcinoma, and basal cell carcinoma with follicular differentiation

BACKGROUND

Both trichoblastoma and basal cell carcinoma (BCC) of the skin are characterized morphologically by the proliferation of basaloid cells; however, BCCs are clinically associated with a more aggressive behavior. An accurate diagnosis of these lesions is essential for effective, timely treatment and appropriate therapeutic decisions.

METHODS

This study includes 40 lesions. Bcl-2 and CD10 immunohistochemistry were performed in all cases and the patterns of expression were analyzed.

RESULTS

Bcl-2 is useful for the detection of BCC with diffuse expression in nests of basaloid cells, but cannot distinguish between BCC with follicular differentiation and trichoblastoma, as both lesions show the same pattern with positive and negative areas. Conversely, CD10 expression can distinguish between trichoblastomas with peritumoral stromal staining and BCCs with epithelial staining. If both stromal and epithelial areas are stained, these cases are classified as BCC with follicular differentiation.

CONCLUSIONS

CD10 is useful for distinguishing between BCC with widespread follicular differentiation and trichoblastomas.

Destruction of the orbit and globe by recurrence of basal cell carcinoma

BACKGROUND

Basal cell carcinoma (BCC) is the most common skin malignancy and represents 90% of eyelid malignancies. Of those that occur on the eyelids, most involve the lower lid. Risk factors for BCC include environmental and genetic factors. There are several clinical presentations, the 2 main forms of which are 1) nodular and 2) morpheaform (or sclerosing). Several treatment options exist, including surgical excision, cryotherapy, radiotherapy, laser surgery, chemotherapy, and photodynamic therapy. The average rate of recurrence is 5%, depending on the type of BCC, the size, the location, and therapeutic approach.

CASE REPORT

The patient described in this case report had basal cell carcinoma of the upper right lid 4 to 5 years prior to examination. At that time the patient was treated with surgical excision and radiotherapy. Subsequently, he had not received any eye care since the initial surgery to remove the malignancy. His entering complaint was drainage and an odor emanating from his right eye. The upper lid was retracted and had a lesion suspicious for BCC. The globe was keratinized, inflamed, and proptotic. He was referred to the oculoplastics service to confirm the recurrence of BCC. They found that the BCC had infiltrated the right globe and the retro-orbital region and probably invaded the adjacent bony margins. He had extensive surgery to remove the tumor and subsequent skin grafting.

CONCLUSION

BCC, when treated early, has excellent surgical outcomes. However, there is no procedure that has a zero recurrence rate. BCC, although rarely metastatic, can be invasive. This case underscores the importance of proper follow-up protocol for all surgical patients as well as patient education that reinforces the importance of follow-up care and self-monitoring on the part of the patient.

Molecular diagnosis of basal cell carcinoma and other basaloid cell neoplasms of the skin by the quantification of Gli1 transcript levels

BACKGROUND

Distinguishing basal cell carcinoma (BCC) from other benign and malignant skin tumors is sometimes a difficult task for the pathologists. Because the activation of hedgehog signals and the up-regulation of its critical transcriptional factor Gli1 are well documented in BCC, a molecular technique measuring Gli1 transcripts may aide the diagnosis.

METHODS

Gli1 transcript levels were measured by real-time quantitative reverse transcriptase polymerase chain reaction (RT-PCR) using RNA extracted from formalin-fixed, paraffin-embedded tissues of 68 cases of various skin tumors. Hematoxylin and eosin-stained pathology slides were independently reviewed by three expert dermatopathologists.

RESULTS

The histological diagnoses were unambiguous in 53 tumors. The tumors included BCC (21), squamous cell carcinoma (13), seborrheic keratoses (8), trichoepithelioma (5), eccrine poroma/porocarcinoma (4), and sebaceous epithelioma/carcinoma (2). In these unambiguous cases, all BCC and trichoepithelioma tumors showed high expression of Gli1mRNA, while the expression was virtually absent in other tumors. The diagnosis was discordant among three pathologists in the remaining 15 tumors. Histological diagnoses included BCC, BCC with sebaceous differentiation, sebaceoma/sebaceous epithelioma, trichoblastoma, trichoepithelioma, basaloid follicular harmartoma, basosquamous carcinoma, etc. Six of them showed high Gli1 transcript levels.

CONCLUSIONS

Quantification of Gli1 transcripts by RT-PCR is helpful in discriminating BCC and trichoepithelioma from other skin tumors.