Granular Cell Dermatofibroma: When Morphology Still Matters

High-Frequency Ultrasound Imaging to Distinguish High-Risk and Low-Risk Dermatofibromas

BACKGROUND

Dermatofibroma has various pathological classifications, some of which pose a risk of recurrence and metastasis. Distinguishing these high-risk dermatofibromas based on appearance alone can be challenging. Therefore, high-frequency ultrasound may provide additional internal information on these lesions, helping to identify high-risk and low-risk dermatofibroma early.

METHODS

In this retrospective study, 50 lesions were analyzed to explore the correlation between clinical and high-frequency ultrasound features and dermatofibroma risk level. Based on their pathological features, the lesions were divided into high-risk (n = 17) and low-risk (n = 33) groups. Subsequently, an identification model based on significant high-frequency ultrasound features was developed.

RESULTS

Significant differences were observed in the thickness, shape, internal echogenicity, stratum basal, and Doppler vascular patterns between the high-risk and low-risk groups. The median lesion thickness for the high-risk dermatofibroma group was 4.1 mm (IQR: 3.2-6.1 mm), while it was 3.1 mm (IQR: 1.3-4.2 mm) for the low-risk dermatofibroma group. In the high-risk dermatofibroma group, irregular morphology was predominant (70.6%, 12/17), the most common being dermis-to-subcutaneous soft tissue penetration (64.7%, 11/17), and heterogenous internal echogenicity was observed in the majority of cases (76.5%, 13/17). On the other hand, regular morphology was more prevalent in the low-risk dermatofibroma group (78.8%, 26/33), primarily limited to the dermis layer (78.8%, 26/33), with homogeneous internal echogenicity also being prevalent in the majority of cases (81.8%, 27/33). Regarding the Doppler vascularity pattern, 69.7% (23/33) of low-risk dermatofibromas had no blood flow, while 64.7% (11/17) of high-risk dermatofibromas had blood flow.

CONCLUSION

High-frequency ultrasound is crucial in distinguishing high-risk and low-risk dermatofibromas, making it invaluable for clinical management.

The Burden of Skin Cancers in Saudi Arabia Through 2011-2022

Introduction Skin cancers are classified into melanoma and non-melanoma or keratinocyte cancers. No recent data are found about the epidemiology of skin cancers in Saudi Arabia. The current study aims to determine the burden of skin cancer in the last 11 years from 2011 to 2022. Methods Patients who were diagnosed with any type of skin cancer were enrolled in the study. The diagnosis was conducted based on histopathology and immunohistochemistry. Different variables like age, type of cancer, type of lesions, and treatment approach used were measured. Results A total of 91 patients were diagnosed with skin cancers during the study period. The head and neck were the most common sites for skin cancers. Only 4/91 cases reported invasive melanoma. Both squamous cell carcinoma (SCC) (34/91) and basal cell carcinoma (BCC) (28/91) were found to be the most reported skin cancers. Other cancers including mycosis fungoides (MF) (10/91), Kaposi's sarcoma (6/91), and dermatofibrosarcoma protuberans (DFSP) (5/91) were also detected. The rest of the detected tumors were rarely detected. Aggressive CD4+/CD4+/CD8+ MF was more prevalent than CD3+/CD4+/CD8- MF cancer cases. CD34+ /S100- DFSP cancers were evident in most of the DFSP cases. Human herpes virus 8 was detected in all Kaposi's sarcoma cases and all of them were HIV-confirmed cases. Surgical treatment was the most frequently used approach to treat skin cancers, followed by phototherapy (9.9%), surgical/radiotherapy (5.5%), surgical/chemotherapy (4.4%), chemotherapy (3.3%), and then chemoradiotherapy immunotherapy (1.1%). Conclusion The incidences of SCC and BCC are relatively high in comparison to other types of skin cancers with the surgical intervention being most frequently used.

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.

Haemorrhage and Survival Times: Medical-Legal Evaluation of the Time of Death and Relative Evidence

Haemorrhage is the name used to describe the loss of blood from damaged blood vessels (arteries, veins, capillaries). Identifying the time of haemorrhage remains a clinical challenge, knowing that blood perfusion of systemic tissues is poorly correlated with the perfusion of specific tissues. In forensic science, one of the most discussed elements is the time of death. This study aims to provide the forensic scientist with a valid model to establish a precise time-of-death interval in cases of exsanguination following trauma with vascular injury, which can be useful as a technical aid in the investigation of criminal cases. To calculate the calibre and resistance of the vessels, we used an extensive literature review of distributed one-dimensional models of the systemic arterial tree as a reference. We then arrived at a formula that allows us to estimate, based on a subject's total blood volume and the calibre of the injured vessel, a time interval within which a subject's death from haemorrhage from vascular injury falls. We applied the formula to four cases in which death had been caused by the injury of a single arterial vessel and obtained comforting results. The study model we have offered is only a good prospect for future work. In fact, we intend to improve the study by expanding the case and statistical analysis with particular regard to the interference factors to confirm its actual usability in practical cases; in this way, useful corrective factors can be identified.

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.

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.

Cutaneous Fibrous Histiocytomas, Ossifying-Variant with Osteoclast-like Giant Cells and Granular Cell-Variant: A Series of Two Unusual Cases with Emphasis on the Differential Diagnosis

The ossifying variant and the granular cell variant are rare subtypes of cutaneous fibrous histiocytoma (CFH), characterized by islands of mature metaplastic bone tissue rimmed by multinucleated osteoclast-like giant cells and by large-sized cells with granular cytoplasm and mildly hyperchromatic nuclei with inconspicuous nucleoli, respectively. We herein present two cases of these unusual CFH variants in a 37-year-old woman and in a 38-year-old man, respectively. The main differential diagnoses, including both benign and malignant lesions, are also discussed.