Tuberculous Ulcerative Skin Lesion of the Penis: A Case Report.

Genitourinary tuberculosis (GUTB), especially penile tuberculosis (PTB), is a disease often overlooked by urological specialists, especially in Europe, where the pathology is less frequent. In this report, we described a case of penile tuberculosis (PTB) characterized by ulcers on the penis. After the patient was administered three months of anti-tuberculosis treatment (isoniazid 0.3 g/qd, rifampicin 0.6 g/qw, and ethambutol 0.75 g/qd), the ulcer disappeared. The patient was followed up for seven months and showed no recurrence.

A Rare Hybrid Skin Cyst of the Scalp With Pilar and Apocrine Features.

Benign epithelial skin cysts containing multiple components of the folliculo-sebaceous apocrine unit are only rarely reported in the literature. Here, we describe a 12-year-old girl who presented with a cystic mass on the vertex of her scalp. Upon resection, it showed a hybrid benign skin cyst with interesting histological features of both pilar and apocrine differentiation. The clinicopathological and imaging findings of this unusual skin cyst, successfully managed by a plastic surgeon and neurosurgeon, are described. Pathologists and clinicians should be aware of this type of skin cyst rarely encountered in their clinical practice.

Report of Basal Cell Carcinoma Occurring With a Desmoplastic Trichilemmoma Successfully Treated With Mohs Micrographic Surgery.

Desmoplastic trichilemmoma, an uncommon variant of trichilemmoma, is a benign adnexal neoplasm originating from the outer root sheath of a hair follicle, which has rarely been associated with atypical basaloid proliferations, including basal cell carcinoma. In this patient case, a 67-year-old female presented to our dermatology clinic for a skin check. On physical examination, a pearly, pink papule was noted on the vertex scalp, and a biopsy was obtained to rule out malignancy. Histologic examination of the lesion favored a desmoplastic trichilemmoma; however, a basaloid neoplasm could not be ruled out. Subsequently, the patient underwent Mohs micrographic surgery, and upon examination of the Stage I Mohs slides, superficial basal cell carcinoma was identified within the lesion. This case serves to further strengthen the known association between basal cell carcinoma and desmoplastic trichilemmoma. In addition, it demonstrates that the presence of basal cell carcinoma may not be observed on the initial biopsy of these lesions, underscoring the utility of complete surgical excision.

Coexistent frontal fibrosing alopecia with ophiasis pattern alopecia areata in a young female: A case report and review of the literature.

This study highlights the possibility of coexistent Frontal Fibrosing Alopecia and ophiasis pattern Alopecia Areata especially in young females which is a rare manifestation. A concomitant shared pathophysiology is suspected to underlie this association.

A rare form of metastatic breast carcinoma mimicking lymphangioma circumscriptum.

Cutaneous metastasis is rare but may indicate an advanced internal malignancy or a recurrence of a previously treated one and is usually associated with a poor prognosis. They may also pose a diagnostic problem as the clinical manifestations are variable and non-specific, which could mimic other benign conditions. We report a case of a 48-year-old female who presented with a 4-year history of erythematous papules and vesicles on the trunk mimicking lymphangioma circumscriptum. Skin biopsy and immunohistochemistry were consistent with cutaneous metastasis from breast carcinoma. Cutaneous metastasis presents in a variety of patterns. A high index of suspicion and a low threshold for skin biopsy are paramount to the early diagnosis and treatment. A histopathologic evaluation will help identify the origin of the cutaneous metastasis and can significantly affect the outcome of the treatment.

Toxic epidermal necrolysis-like cutaneous toxicity following chimeric antigen receptor T-cell therapy in recurrent large B-cell lymphoma.

Chimeric antigen receptor (CAR) T-cell therapy has demonstrated remarkable success in treating various B-cell malignancies, redirecting T-cell cytotoxicity toward cancer cells. Despite its efficacy, CAR-T therapy is associated with potential risks, including cytokine release syndrome (CRS) and cytopenia. We present a case of a 69-year-old man with diffuse large B-cell lymphoma treated with axicabtagene-ciloleucel CAR-T therapy, who developed a rare and severe cutaneous toxicity resembling toxic epidermal necrolysis (TEN). The patient exhibited persistent fevers, CRS, and subsequent development of a widespread erythematous macular eruption, progressing to vesiculation with bullae. Notably, allopurinol-induced TEN was considered with the patient's recent exposure to allopurinol, although the onset and minimal mucosal involvement did not align with typical presentations of allopurinol-induced cases. The cutaneous reaction, distinct from typical SJS/TEN, showed minimal mucosal involvement and coincided with the cytokine release storm, differing from allopurinol-induced TEN. Despite the absence of guidelines, the patient was managed with systemic steroids, achieving significant improvement. This case expands the spectrum of CAR-T therapy-related cutaneous toxicities, highlighting the need for early recognition of histopathology and tailored management by dermatologists. Further understanding of these reactions is crucial for optimizing the safety profile of this groundbreaking immunotherapy.

Melan-A-Positive Granular Cell Tumor With Extensive Intraneural and Perineural Spread: A Rare Case Report.

Cutaneous granular cell tumors (GCTs) are rare tumors that typically exhibit benign clinical behavior and are likely of Schwann cell origin. Some histologic and immunohistochemical variants of GCTs may present challenges due to infiltrative growth patterns, perineural invasion, and expression of Melan-A. In this case report, we present a 27-year-old male who had previously been diagnosed with a typical GCT on the back a few years ago. The current biopsy from the proximal palm demonstrated a cytologically similar tumor with extensive perineural spread and notable positivity for Melan-A. Although uncommon, these features are consistent with the histological appearances of GCTs. The current views on the histogenesis of GCTs, clinical associations, differential diagnosis with melanoma, and histological criteria for malignant GCTs are discussed. A panel of immunohistochemical stains, including Inhibin-α and preferentially expressed antigen in melanoma (PRAME), is proposed for use in rare instances of Melan-A-positive GCTs.

A rare case of circumferential osteoinvasive subungual melanoma: A case report.

Subungual melanoma is a rarer form of melanoma encountered in clinical practice that often has a poor prognosis because it presents with advanced disease. We report a case of a 46-year-old male with a circumferential osteoinvasive melanoma that invaded the superior and lateral aspects of the periosteum of the distal phalanx. We discuss pathologic findings and common physical exam findings to facilitate earlier diagnosis of subungual melanoma.

A case of diagnostic uncertainty: High-grade melanocytoma versus balloon cell melanoma in a pediatric patient.

An 11-year-old female was referred from an outside institution after a diagnostic biopsy and subsequent excision of a progressively enlarging reddish-brown nodule demonstrated features concerning for a balloon cell nevus with severe atypia versus a high-grade melanocytoma. Upon review of the initial biopsy specimen and molecular data, we favored the diagnosis to be consistent with a high-grade melanocytoma with balloon cell changes while considering the possibility of balloon cell melanoma due to concerning histopathologic and genetic abnormalities. In this case study, we discuss critical diagnostic considerations in this rare pediatric case and highlight important pathologic and clinical features of melanocytomas and balloon cell melanoma.

Diagnostic discordance among histopathological reviewers of melanocytic lesions.

BACKGROUND: Histopathological examination is adequate for the diagnosis of most cutaneous melanocytic neoplasms. However, there is a subset that is either difficult to definitively diagnose or would have diagnostic disagreement upon review by multiple dermatopathologists if a more exhaustive review was performed. METHODS: Melanocytic lesions underwent an independent, blinded diagnostic histopathological review of hematoxylin and eosin-stained sections. Each lesion was reviewed by three to six dermatopathologists and categorized as benign, malignant, or unknown malignant potential (UMP). Diagnoses were grouped as concordant (all the same designation); opposing (received benign and malignant designations); majority (single designation with the highest number of diagnoses, no benign/malignant opposing designations); and non-definitive (equal number of non-opposing designations [i.e., benign/UMP or malignant/UMP]). Lesions with equivocal designations (concordant or majority UMP, opposing, majority, and non-definitive) were utilized in a patient treatment model of projected surgical treatment discrepancies. RESULTS: In total, 3317 cases were reviewed, and 23.8% of lesions received equivocal diagnoses. Of these, 7.3% were majority benign, 4.8% were majority malignant, 2.7% were majority UMP, 0.5% were concordant UMP, 6.9% were opposing, and 1.6% were non-definitive. Patient treatment models of those with equivocal lesions (n = 788) revealed a potential of overall surgical treatment variations ranging from 18% to 72%, with the highest variation amongst lesions with opposing, non-definitive, or majority UMP (40%-72%) diagnoses. CONCLUSION: Histopathologic review in this large cohort demonstrated substantial diagnostic variation, with 23.8% of cases receiving equivocal diagnoses. We identified diagnostic ambiguity even in lesions where a definitive diagnosis was previously rendered by a single real-world dermatopathologist. The combined clinical impact of diagnostic discordance or a final diagnosis of UMP is highlighted by high diagnosis-dependent treatment variation in the patient treatment model, which could be underreported in a real-world setting, where review by more than one to two dermatopathologists is relatively rare.

A Rare Case of a Primary Cutaneous Collision Tumor Comprising Malignant Melanoma and Rhabdomyosarcoma.

This case reports a 35-year-old man who presented with a painful erythematous nodule on his right posterior calf. He first noticed this nodule several years ago and it often bled upon contact with clothing. An excisional biopsy of the skin lesion revealed two distinct populations of cells. One population of epithelioid cells stained positive for Mart-1, HMB45, and SOX-10, confirming the diagnosis of malignant melanoma. The second population of cells stained positive for desmin and calponin, confirming the diagnosis of sarcoma with muscular differentiation. Subsequently, these unusual findings led to the diagnosis of a collision tumor comprising malignant melanoma and rhabdomyosarcoma. Follow-up PET/CT and brain MRI revealed no metastasis from the primary skin lesion. This case highlights a rare combination of cell types found within a collision tumor in addition to providing details on how to diagnose this skin lesion.

Relationship between dermoscopic and histopathological findings of extradigital glomus tumors.

In extradigital glomus tumors, (1) noncontact and (2) contact dermoscopy show (1) a central purplish-white area corresponding to tumor nests surrounding enlarged vessels, a peripheral yellow-white area corresponding to mucin deposition, melanin granules, and fibrous tissue, and (2) white reticular and linear cord areas corresponding to pseudocapsules and collagen fibers.

Cutaneous Collagenous Vasculopathy: A Rare Entity Treated With Pulsed Dye Laser.

Cutaneous collagenous vasculopathy (CCV) is a rare idiopathic dermal microangiopathy. Clinically, it presents as diffuse cutaneous telangiectasias that are indistinguishable from other benign vascular entities, thereby posing a diagnostic challenge. We present a case of CCV successfully treated with pulsed dye laser (PDL). A 27-year-old male presented with generalized erythematous macules, diagnosed as CCV via histopathology. After a successful test spot, PDL treatment resulted in significant improvement. The pathogenesis of CCV involves altered dermal microvasculature and veil cell activation. Epidemiologically, it primarily affects Caucasians, most often in the middle-aged adult population. A negative family history of similar lesions can help narrow down the differential diagnosis. Diagnosis requires biopsy, with histopathological examination demonstrating vessel ectasia and collagenous vessel wall thickening. Given its rarity, CCV presents diagnostic and management challenges though PDL emerges as a promising treatment modality for this condition.

Tumid Lupus Erythematosus (TLE): A Review of a Rare Variant of Chronic Cutaneous Lupus Erythematosus (cCLE) with Emphasis on Differential Diagnosis.

Tumid lupus erythematosus (TLE) has been the subject of heated debate regarding its correct nosographic classification. The definition of TLE has changed over time, varying according to the different studies performed. In this review, we address the initial definition of TLE, the changes that have taken place in the understanding of TLE, and its placement within the classification of cutaneous lupus erythematosus (CLE), with a focus on clinical, histopathological, immunophenotypical, and differential diagnosis aspects.