Trichoblastoma mimicking basal cell carcinoma and the approach to its management: Case report

[A case of trichoblastoma of the auricular cavity and review of the literature]

Trichoblastoma（TB） is a rare germ cell skin adnexal tumor of the hair, and it is a rare follicular tumor of the skin that differentiates from the hair germ epithelium and is often regarded as a benign skin tumorHowever, it is poorly confined and has a local infiltrative growth pattern. tb occurs in the head and neck region, especially in the face, and presents clinically as a slow growing, well-defined and elevated nodule. TB is routinely treated surgically. Due to the lack of universally accepted treatment guidelines or protocols, the recurrence rate after surgery is high, which makes clinical cure more difficult. In this study, a 65-year-old female patient was found to have a swelling with recurrent rupture and pus flow from the right external auditory canal opening and the auricular cavity. After initial misdiagnosis as otitis externa, she was treated with conventional anti-infective therapy, but her symptoms did not resolve and gradually worsened before coming to our hospital. The condition presented in this case is relativelyrare,therepre,timely and accurate diagnosis and treatment are crucial for prognosis improvement of such diseases.

Nevus Sebaceous of Jadassohn in Adults-Can Reflectance Confocal Microscopy Detect Malignant Transformation?

Nevus sebaceous of Jadassohn (NSJ) is a rare congenital lesion that affects the adnexal structures of the skin. It is typically located on the scalp and face of females and presents as a well-defined, slightly elevated, yellow lesion. It is also linked to a high risk of secondary tumors, which are more frequently benign than malignant. In vivo reflectance confocal microscopy (RCM) is a non-invasive imaging technique that provides a horizontal image of the skin with a resolution similar to histology. We report a case of basal cell carcinoma (BCC) developed in an NSJ with its dermoscopic, confocal, and histopathological features. A 49-year-old female presented with a well-circumscribed, 1 cm-diameter verrucous, yellowish lesion surrounded by a poorly defined, slightly erythematous, translucent plaque, located on the scalp in the temporoparietal region, which had been present since birth, grew at puberty, and changed its appearance in the last three years. Dermoscopy of the central lesion revealed yellow globules grouped into clusters, with peripheral linear and arborescent thin vessels, surrounded by several translucent nodular lesions with fine, arborizing vessels. RCM examination showed large, monomorphic cells with a hyperreflective periphery and a hyperreflective center located on the central lesion, corresponding to sebocytes, surrounded by multiple dark silhouettes lined with hyperreflective bands of thickened collagen, corresponding to tumor islands. The histopathological findings confirmed the diagnosis of BCC developed on an NJS. RCM can be a useful technique for the non-invasive examination and monitoring of these lesions, taking into account their transformation risk and preventing unnecessary excisions that might have a detrimental aesthetic impact on patients.

A case of racemiform trichoblastoma in a dog

Trichoblastoma, which is common in dogs, is now occurring with other cellular changes outside the recognized forms to warrant their continuous evaluation for proper elucidation even as their causes largely remain unknown. A case at hand involved a 9-year-old Caucasian dog, which weighed 35 kg with chief complaint of a progressive bleeding mass on the scalp. The dog had an up-to-date vaccination record and all vital parameters were within optimum ranges. The surgical excision of the firm, solitary, and alopecic mass with traumatized upper surface revealed the presence of a well-demarcated and unencapsulated mass composed of grapes-like nests of basaloid epithelial cells within follicular stroma devoid of stromal necrosis, inflammatory cellular infiltration, and neoplastic epidermal connection. However, there was tissue necrosis, hemorrhages, and inflammatory cellular infiltrates on the exposed upper part of the traumatized growth. Immunohistochemical analysis showed positive reactivity to AE1/AE3, CK5/6, and p63 but negative immunoreactivity to CK7, CK20, CEA, and TTF-1. The histomorphological and immunohistochemical evaluation of the mass on the scalp of the dog suggested a solitary racemiform trichoblastoma with a traumatized exposed upper part despite basal cell carcinoma mimicry where histological diagnosis currently hold sway over immunohistochemical evaluation.