Reflectance Confocal Microscopy and Dermoscopy for the Diagnosis of Solitary Hypopigmented Pink Lesions: A Narrative Review.

Diagnosing solitary pink skin lesions poses a significant challenge due to the scarcity of specific clinical and dermoscopic criteria. Several benign lesions, such as cherry angioma, clear cell acanthoma, dermal nevus, keloid, hypertrophic scar, and Spitz nevus, often exhibit similar clinical and dermoscopic features. This similarity extends to some malignant lesions, including basal cell carcinoma, actinic keratosis, and amelanotic melanoma, making differentiation difficult. Recent studies highlight the enhanced diagnostic accuracy of reflectance confocal microscopy (RCM), which offers increased sensitivity and specificity compared to dermoscopy alone for diagnosing skin cancer. This study aims to summarize the application of dermoscopy and RCM in distinguishing between benign and malignant pinkish-reddish skin lesions. The integration of RCM with traditional dermoscopic techniques improves the ability to accurately identify and differentiate these lesions. However, it is crucial to note that for any suspicious lesions, a final diagnosis must be confirmed through surgical excision and histopathological evaluation. This comprehensive approach ensures accurate diagnosis and appropriate treatment, highlighting the importance of combining advanced imaging techniques in clinical practice.

Multidisciplinary Approach to Melanoma: A Case Report on Below-Knee Amputation and Lymph Node Dissection.

A 65-year-old male presented with progressive swelling and difficulty in walking due to a right foot sprain. Initial treatments were conducted in Chandrapur, followed by referral to Acharya Vinoba Bhave Rural Hospital for further evaluation and management. The patient, a known case of diabetes mellitus and hypertension, reported an insidious onset of right foot swelling over two months. A physical examination revealed stable vital signs; no significant abnormalities were observed during the systemic examination. Laboratory investigations indicated mild anemia and slightly elevated liver enzymes. Imaging studies, including MRI and CT scan, identified an ill-defined lesion on the medial aspect of the right foot, consistent with dermatofibroma. The patient underwent a below-knee amputation with inguinal lymph node dissection on 31st May 2024. The procedure, performed under spinal and epidural anesthesia, involved meticulous dissection and ligation, with the posterior flap sutured using Ethilon 2-0 (Ethicon, Cincinnati, OH, USA). Post-operative management included IV antibiotics and supportive care. The patient's postoperative course was uneventful, with a healthy suture line and stable vitals upon discharge. Histopathological evaluation of the resected specimen confirmed melanoma, with immunohistochemistry revealing HMB-45 and S-100 negativity. The patient was discharged with advice on local hygiene, physiotherapy, dietary recommendations, and a follow-up schedule. This case highlights the importance of comprehensive multidisciplinary management in treating malignancies complicated by chronic conditions. Early diagnosis, appropriate surgical intervention, and diligent post-operative care are crucial for favorable outcomes in complex oncological cases.

Giant thigh hemosiderotic/aneurysmal dermatofibroma: Case report with radiologic-pathologic correlation.

Hemosiderotic/aneurysmal variant of dermatofibroma (DF) is infrequent and may be misdiagnosed with malignant lesions. We report the case of a giant (7.6cm) subcutaneous hemosiderotic/aneurysmal DF (H/ADF) of the thigh in a 53-year-old female patient. Internal arterial and venous hypervascularity was seen by spectral Doppler ultrasound. Magnetic resonance image showed a discrete homogeneous hypointense in T1-weighted images (WI) and T2-WI mass, with hyperintense areas in fat-suppressed T2-WI. The histology revealed a monotonous fusocelular proliferation without atypia, positive for CD163, factor XIIIa and CD10. Widely distributed hemosiderin pigment and two blood-filled pseudovascular spaces lacking endothelial lining were present. H/ADF was diagnosed. The mass was removed but surgical margins were affected. The patient did not present local relapse or distant metastasis. H/ADF are unusual cutaneous soft tissue tumours that can be clinically, radiologically and histopathologically confused with malignant lesions such as melanomas, vascular lesions or sarcomas, especially in giant cases.

Ex Vivo Confocal Laser Scanning Microscopy in Rare Skin Diseases.

While ex vivo confocal laser scanning microscopy has previously demonstrated its utility in most common skin diseases, its use in the assessment of dermatological entities with lower incidence remains unexplored in most cases. We therefore aimed to evaluate the diagnostic efficacy of some rare skin tumors as well as a few inflammatory skin diseases, that have not yet been studied in ex vivo confocal laser scanning microscopy. A total of 50 tissue samples comprising 10 healthy controls, 10 basal cell carcinoma, 10 squamous cell carcinoma, and 20 rare skin conditions were imaged using the newest generation ex vivo confocal microscopy (Vivascope 2500 M-G4, Vivascope GmbH, Munich, Germany). Three blinded investigators were asked to identify characteristic features of rare skin disorders and distinguish them from more common skin diseases in the ex vivo confocal microscopy images. Our findings present the capability of ex vivo confocal microscopy to display distinctive morphologic patterns in common and rare skin diseases. As might be expected, we found a strong correlation between imaging experience and diagnostic accuracy. While the imaging inexperienced dermatohistopathologist reached 60% concordance, the imaging-trained dermatologist obtained 88% agreement with dermatohistopathology. The imaging-trained dermatohistopathologist achieved concordance up to 92% with gold-standard dermatohistopathology. This study highlights the potential of ex vivo confocal laser scanning microscopy as a promising adjunct to conventional dermatohistopathology for the early and precise identification of rare dermatological disorders.

Metastasizing aneurysmal dermatofibroma initially diagnosed as angiosarcoma confirmed by CD63::PRKCD fusion gene detection with nanopore sequencing.

Dermatofibroma (DF) is a benign tumor that forms pedunculated lesions ranging in size from a few millimeters to 2 cm, usually affecting the extremities and trunks of young adults. Histopathologically, DF is characterized by the storiform proliferation of monomorphic fibroblast-like spindle cells. In addition to neoplastic cells, secondary elements such as foamy histiocytes, Touton-type giant cells, lymphoplasmacytes, and epidermal hyperplasia are characteristic histological features. Several histological variants, including atypical, cellular, aneurysmal, and lipidized variants, have been reported; cases with variant histologies are sometimes misdiagnosed as sarcomas. We present a case of metastasizing aneurysmal DF that was initially diagnosed as an angiosarcoma on biopsy. A 26-year-old woman was referred to our hospital with a gradually enlarging subcutaneous mass in her lower left leg. Positron emission tomography-computed tomography revealed high fluorodeoxyglucose uptake not only in the tumor but also in the left inguinal region. On biopsy, ERG and CD31-positive atypical spindle cells proliferated in slit-like spaces with extravasation, leading to the diagnosis of angiosarcoma. Histology of the wide-resection specimen was consistent with DF, and lymph node metastasis was also observed. Nanopore DNA sequencing detected CD63::PRKCD fusion and copy number gain, although CD63 was not included in the target region of adaptive sampling. This report highlights the importance of recognizing the unusual clinical, radiological, and pathological features of DF to avoid misdiagnosis, and the potential diagnostic utility of nanopore sequencer.

"Unusual Presentation of Epitheloid Dermatofibroma- Rare Case Report".

Dermatofibroma is a commonly occurring cutaneous entity usually centered within the skin's dermis. Dermatofibromas are referred to as benign fibrous histiocytomas of the skin, superficial/cutaneous benign fibrous histiocytomas, or common fibrous histiocytoma. These mesenchymal cell lesions of the dermis clinically are firm subcutaneous nodules that occur on the extremities in the vast majority of cases and may or may not be associated with overlying skin changes. A 20 years old male presented to ENT OPD, at a private hospital, with complaints of a huge mass over right side of face since 15 years, which was slowly growing and not associated with pain. On clinical examination, hard, non tender, lobulated cauliflower like mass located over right side of face extending from right side temporal region to upper border of mandible from superior to inferior. From anterior to posterior it was extending from lateral 1/3rd of forehead and covering lateral canthus of right eye upto right side tragus. We have taken incisional biopsy which was suggestive of dermatofibroma. Then surgery was performed with patient's consent. Excision with 1 cm free margin was done. Raw area was covered with full thickness skin grafting and advancement flap. We found no recurrence till date. Dermatofibroma in the head and neck region is less common and often present a difficult differential diagnosis like Dermatofibrosarcoma protuberans, Kaposi Sarcoma, Basal cell carcinomas. The aim of case report is to represent case of dermatofibroma of epitheloid variety which is unusual in size.

Multiple Eruptive Dermatofibroma: A Case Report.

Background: Multiple eruptive dermatofibroma (MEDF) is a rare presentation of dermatofibroma which is frequently associated with underlying diseases such as human immunodeficiency virus infection or systemic lupus erythematosus. It generally presents a characteristic histology with hyperplasia of the epidermis, prominent bundles of collagen and a diffuse proliferation of fibrocytes. Case Summary: We report a case of MEDF in a 30-year-old man who presented with a large number of dark brownish red maculopapules distributed over the trunk and extremities for more than 10 years. According to the pathology, the patient was diagnosed with MEDF. Infections and autoimmune diseases were ruled out. As he had no clinical symptoms, and presented with lesions widely distributed over the body, we gave no special treatment, but suggested a regular examination. Conclusion: Patients with MEDF usually have no pain and pruritus. If human immunodeficiency virus infection and systemic lupus erythematosus and other causes are ruled out, and lesions are widely distributed over the body, regular check-up is recommended without specific treatment.

168 Cases of aneurysmal dermatofibroma and 29 cases of hemosiderotic dermatofibroma: A clinicopathologic study.

OBJECTIVES: Aneurysmal dermatofibroma (ADF) and hemosiderotic dermatofibroma (HDF) are rare variants of dermatofibroma (DF) characterized by distinct histologic features. While HDF is traditionally considered a precursor to ADF, supporting evidence is limited, and the etiology remains unclear. A retrospective analysis of 2128 DF cases (2016-2019) was conducted to investigate the clinicopathologic characteristics of ADF, HDF, and other DFs. METHODS: Histopathologically diagnosed DF cases were examined for ADF and HDF. Univariate analyses were performed to compare clinicopathologic features. RESULTS: Among the cases, 168 (7.9%) were ADF and 29 (1.4%) were HDF. Aneurysmal dermatofibroma and HDF shared several common characteristics, including lower occurrence in females, larger size, and increased cellularity (all P < .0001). Notably, 29% of ADFs lacked hemosiderin deposition. Aneurysmal dermatofibroma primarily manifested on exposed areas (face and forearm, both P < .001). In contrast, 41% of HDFs occurred on the lower leg (P = .018), and all lower leg HDFs exhibited signs of venous stasis, distinguishing them from other HDFs (P < .0001). CONCLUSIONS: Our findings indicate a potential close relationship between ADF and HDF. Contrary to conventional beliefs, we also presented the possibility of ADF progressing into HDFs. Physical trauma may induce ADF, and HDFs may emerge from ADFs in conjunction with venous stasis in the lower extremities.

A study of collagen refractility in dermatofibroma and dermatofibrosarcoma protuberans using diffractive microscopy.

BACKGROUND: Diffractive microscopy creates contrast within samples that are otherwise uniform under bright light. This technique can highlight subtle differences in refractive indices within birefringent samples containing varying amounts of mature collagen. Dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP) possess differences in their mature collagen content and, therefore, may be distinguishable using diffractive microscopy. METHODS: Two hundred forty-two DF and 85 DFSP hematoxylin-eosin (H&E)-stained specimens were analyzed using diffractive microscopy. Data regarding the distribution pattern and strength of refractility was recorded. RESULTS: DFSP was more frequently found to be focally, weakly, or non-refractile (82.9%; n = 68) under diffractive microscopy, while DF more often showed diffusely bright refractility (52.9%; n = 128). DFSP samples with diffuse refractility in portions of the lesion (17.1%; n = 14) also exhibited a unique checkerboard pattern distinct from that which was seen in DF samples. CONCLUSIONS: The absence of diffuse refractility was more closely associated with DFSP, as was the presence of a unique checkerboard diffraction pattern. Despite high sensitivity (Sn = 82.9%), absent refractility was not a specific test (Sp = 52.9%), with 47.1% (n = 114) of DF samples sharing this feature. The distinction between DF and DFSP is often diagnosed using H&E alone. In difficult cases, examination of collagen under diffractive microscopy may be useful in distinguishing DFSP from DF and provide an alternative cost-effective tool to immunohistochemical staining.

Epidermal inclusion cyst embedded in benign fibrous histiocytic lesion with prominent epithelioid morphology.

Benign fibrous histiocytoma also known as dermatofibroma is one of the common mesenchymal neoplasms. It commonly develops in young adult with female predominance and predilection for the extremities, particularly lower extremities. Implantation of epidermis in the dermis or subcutaneous tissues may lead to the formation of epidermal inclusion cyst, which is the most common type of epithelial cyst. Development of epidermal inclusion cyst within a benign fibrous histiocytoma is a rare occurrence. This is a unique case of two unrelated lesions.

Dermatofibrosarcoma Protuberans Presenting as a Primary Breast Mass.

Dermatofibrosarcoma protuberans (DFSP) is an atypical soft tissue malignancy that affects the dermis and subcutaneous tissue. The cause of DFSP is not clearly understood. This report highlights a rare case of DFSP of the left breast. We report a case of an 18-year-old female with past medical history of type 1 diabetes mellitus, who presented to the breast imaging clinic with a six-month history of left breast lump and associated skin discoloration. The patient had a dedicated left breast ultrasound which showed an indistinct, oval, hyperechoic mass in the superficial breast, measuring 1.4 x 1.0 x 2.5 cm with mild internal vascularity. An ultrasound-guided biopsy of this left breast mass was recommended and performed approximately three weeks later, demonstrating DFSP. The patient was then advised for consultation with Oncology, Surgical Oncology, and Radiation Oncology, to which surgical excision was the final recommendation. The patient had a wide local surgical excision procedure for her left breast mass with surgical pathology confirming negative margins shortly thereafter. This case highlights a great index of suspicion that should be taken when evaluating palpable breast masses with associated skin discoloration in young patients.

Pulmonary Metastasising Aneurysmal Fibrous Histiocytoma: A Case Report, Literature Review and Proposal of Standardised Diagnostic Criteria.

An aneurysmal fibrous histiocytoma is a rare cutaneous soft-tissue tumour which accounts for approximately 0.06% of all dermatopathologies. Metastasis is exceedingly uncommon, to the point that there have only been eight reported cases in the scientific literature. We present the case of a 25-year-old male with a primary aneurysmal fibrous histiocytoma located in the nuchal region which exhibited rapid growth and abrupt ulceration over a short time span and showed signs of locoregional aggressive infiltration. A subsequent histopathological analysis confirmed the presence of diffuse solid and cystic pulmonary metastases. Further genetic sequencing verified LAMTOR1-PRKCD fusion. This case report seeks to review the existing literature on aneurysmal fibrous histiocytoma, discuss the challenges of differential diagnosis and propose standardised diagnostic criteria.

Increased Occurrence of Cutaneous Leiomyomas and Dermatofibromas in Patients with Uterine Leiomyomas without Fumarate Hydratase Gene Mutations.

Leiomyomas are smooth muscle-derived benign neoplasms that can affect all organs, most frequently in the uterus. Fumarate hydratase gene (FH) mutation is characterised by an autosomal dominant disease with increased occurrence of renal tumours, but also by cutaneous (CLs) and uterine leiomyomas (ULs). So far, an increased occurrence of skin tumours in non-mutated patients with ULs has not been verified. To this aim, a case-group of women who were FH non-mutated patients surgically treated for ULs (n = 34) was compared with a control-group (n = 37) of consecutive age-matched healthy women. The occurrence of skin neoplasms, including CLs and dermatofibromas (DFs), was evaluated. Moreover, the microscopic features of FH non-mutated skin tumours were compared with those of an age-matched population group (n = 70) who presented, in their clinical history, only one type of skin tumour and no ULs. Immunohistochemical and in vitro studies analysed TGFß and vitamin D receptor expression. FH non-mutated patients with ULs displayed a higher occurrence of CLs and DFs (p < 0.03 and p < 0.001), but not of other types of skin tumours. Immunohistochemistry revealed a lower vitamin D receptor (VDR) expression in CLs and DFs from the ULs group compared with those from the population group (p < 0.01), but a similar distribution of TGFß-receptors and SMAD3. In vitro studies documented that TGFß-1 treatment and vitamin D3 have opposite effects on α-SMA, TGFßR2 and VDR expression on dermal fibroblast and leiomyoma cell cultures. This unreported increased occurrence of CLs and DFs in FH non-mutated patients with symptomatic ULs with vitamin D deficiency suggests a potential pathogenetic role of vitamin D bioavailability also for CLs and DFs.

Challenging Patterns of Atypical Dermatofibromas and Promising Diagnostic Tools for Differential Diagnosis of Malignant Lesions.

Dermatofibroma (DF) or fibrous histiocytoma is one of the most frequent benign cutaneous soft-tissue lesions, characterized by a post-inflammatory tissue reaction associated with fibrosis of the dermis. Clinically DFs have a polymorphous clinical aspect from the solitary, firm, single nodules to multiple papules with a relatively smooth surface. However, multiple atypical clinicopathological variants of DFs have been reported and, therefore, clinical recognition may become challenging, leading to a more burdensome identification and sometimes to misdiagnosis. Dermoscopy is considered an important tool in DFs diagnosis, as it improves diagnostic accuracy for clinically amelanotic nodules. Although typical dermoscopic patterns are most frequently seen in clinical practice, there have also been some atypical variants described, mimicking some underlying recurrent and sometimes harmful skin afflictions. Usually, no treatment is required, although an appropriate work-up may be necessary in specific cases, such as in the presence of atypical variants or a history of recent changes. This narrative review's aim is to summarize current evidence regarding clinical presentation, positive and differential diagnosis of atypical dermatofibromas and also to raise awareness about the importance of specific characteristics of atypical variants to better differentiate them from malignant conditions.

Clinical and pathological studies of eight cases of lipidized fibrous histiocytoma.

Lipidized fibrous histiocytoma (FH) is a rare type of FH. The present study aimed to describe the clinical and pathological features of lipidized FH. A total of eight patients diagnosed with lipidized FH were retrospectively reviewed in the present study. The cohort included three male and five female patients (male to female ratio, 1.7:1) with a mean age of 48 years (range, 38-62 years). In total, four tumors were located on the buttock, three on the lower leg and one on the forearm. Histological, lipidized FH showed a wide spectrum. Some cases included prominent stromal hyalinization and hyalinized vessels with scant lipid-laden histiocytes. Other cases exhibited the prominent lipid-laden histiocytes and scant stromal hyalinization. Overall, lipidized FH must be differentiated from other benign and malignant tumors, taking into account the therapeutic and prognostic differences between these different entities.

Dermatofibromas with Aberrant Expression of CD34 Protein: A Systematic Review and a Reappraisal of Clinicopathological Features and Histogenesis.

BACKGROUND: Dermatofibromas (DFs) are benign fibrohistiocytic lesions that usually do not express CD34 protein. This study aimed to analyze the literature concerning the immunohistological and ultrastructural features of DFs. It also related these features to the histogenesis of these lesions. METHODS: This study included a PubMed literature search for studies addressing the clinicopathological, ultrastructural, and immunohistochemical features of DFs. It also presented some current cases of CD34-negative DFs and a subset of these lesions with aberrant expression of this protein. RESULTS: Analysis of the PubMed literature revealed that DFs with an aberrant expression of CD34 are rare tumors that commonly affect the extremities of adult females. Separating these tumors from dermatofibrosarcoma protuberans (DFSP, CD34-positive tumors) requires using a large panel of immunostains. Ultrastructurally, DFs are composed of diverse cell types, including cells with histiocytic, myofibroblastic, and fibroblastic features. An analysis of the DFs described by this study revealed that cases with an aberrant expression of CD34 protein had slightly high mean age and male sex predominance when compared to CD34-negative cases. The former commonly affected the extremities. There was no evidence of local recurrence or distant metastasis on follow-up. CONCLUSIONS: DFs have the potential to express CD34 protein, defining a rare aberrant phenotype, which was not associated with any differences in the outcome as compared to CD34-negative DFs.

Keloidal dermatofibroma: Clinicopathological comparison of 52 cases with a series of 2077 other dermatofibromas.

Dermatofibroma is a common benign skin lesion with a contested etiology: some believe it is a neoplasm while others propose minor injuries initiate it. Many dermatofibroma variants have been described, including keloidal dermatofibroma, which is unusual by bearing keloidal collagen. Keloidal dermatofibroma was first described in 1998 and only 15 cases have been reported. Since keloids are driven by skin injuries, the existence of keloidal dermatofibroma has been suggested to support the injury hypothesis of dermatofibroma etiology. To better understand keloidal dermatofibroma characteristics and gain clues regarding dermatofibroma etiology, consecutive keloidal dermatofibroma cases (n = 52) and dermatofibroma without keloidal collagen (n = 2077) that were histopathologically diagnosed in 2016-2019 were identified from the records of a Japanese dermatopathology laboratory and compared in terms of demographic, clinical, and histopathological characteristics by univariate analyses. Compared to other dermatofibromas, keloidal dermatofibromas occurred more frequently on the forearm and hand (P < 0.0001 and 0.0019), especially the wrist dorsum, and in the superficial skin layer (P < 0.0001). Keloidal dermatofibromas also demonstrated more cellularity and hemorrhage (both P < 0.0001). Correlation analyses between keloidal collagen amount and keloidal dermatofibroma size (a proxy of time-since-onset) did not support the notion that keloidal collagen deposition and keloidal dermatofibroma formation are triggered simultaneously. Recent injury, as indicated by fresh hemorrhage, was equally common in putatively older and younger keloidal dermatofibromas. Thus, keloidal collagen in keloidal dermatofibromas could be due to injury to preexisting dermatofibromas, which suggests that the keloidal dermatofibroma entity does not prove the injury hypothesis. Commonalities between keloids and keloidal dermatofibromas suggest a link between genetics, provocative events that induce myofibroblast differentiation, and keloidal collagen production.

Dermatofibroma-like dermal non-neural granular cell tumor.

Non-neural granular cell tumor (NNGCT) is a rare tumor with uncertain lineage. It presents as an asymptomatic polypoid or plaque-like lesion, especially on trunk. Because the granular cells are usually strongly reactive with S-100 stain, conventional granular cell tumors (GCTs) are regarded as those of neural or Schwann cell origin. Unlike GCTs, NNGCT is not reactive for S-100 protein and is thought to derive elsewhere, presumably from mesenchymal stem cells. A 20-year-old woman presented with a solitary, dermatofibroma-like, brownish nodule on her right arm. The lesion developed 3 months before presentation without subjective symptoms. Histopathologic examination revealed a grenz zone overlying a poorly circumscribed tumor extending through the reticular dermis. The tumor cells were large and polygonal, and they had numerous eosinophilic small granules in the cytoplasm. Immunohistochemical stains were positive for CD68, vimentin, factor XIIIa, CD10, and cyclin D1. Stains for S-100 protein, neuron-specific enolase, and CD34 were negative. Based on these findings, the lesion was diagnosed as dermal NNGCT.