SOX10 (SRY-Box 10)

Following confirmation of multiple lung metastases, the patient was treated with doxorubicin monotherapy. Subsequent next-generation sequencing (NGS) revealed a RET fusion, leading to the diagnosis of an RET-rearranged spindle cell neoplasm. This case highlights the importance of genomic testing for certain spindle cell sarcomas and the potential benefit of RET-specific inhibitors against RET-altered sarcomas.

NGS identified an AKAP9 (exon 32)::BRAF (exon 9) fusion, without TERT promoter mutations or other high-risk alterations. This case highlights a rare molecular subset of Spitz melanocytoma and underscores the importance of integrated molecular and histopathological assessment for accurate diagnosis, prognostic evaluation, and potential targeted therapy.

Given the tumour's unresectable nature due to proximity to critical mediastinal structures and the patient's comorbidities, she was initiated on a modified combination immune checkpoint inhibitor regimen with nivolumab and ipilimumab. This case highlights the importance of a meticulous diagnostic approach to solitary pulmonary lesions and underscores the evolving role of immunotherapy in managing rare malignancies such as PMML. Reporting such cases enhances the clinical understanding and guides future management of this rare disease.

S100, SOX10, neurofilament and desmin are typically negative. While perineuriomas behave in a benign fashion, complete surgical excision is recommended.

Vulval pigmentation presents a diagnostic challenge, as the features of vulval melanosis can overlap with those of melanoma. This unusual case of a patient with LS, vitiligo and vulval melanosis highlights the importance of taking multiple biopsies in vulval conditions with variable pigmentation to ensure accurate clinicopathological correlation.

The time from referral to definitive excision was within the national target range, so in this series there was no significant delay to treatment due to misdiagnosis. To minimize diagnostic delays clinicians should maintain a high suspicion for AM in nonpigmented lesions with atypical features, particularly in Fitzpatrick skin types I-II and older patients with chronic photodamage.

PD-L1 and SOX10 expression were associated with unfavorable prognostic factors as well as shorter OS and RFS. Further investigation is warranted to elucidate the molecular pathways through which SOX10 may regulate PD-L1 expression and to explore implications for immunotherapy response in patients with HCC.

Complete excision with clear margins is recommended. While most of the CMTCTs exhibit indolent biological behaviors, rare cases may recur locally or metastasize, warranting close follow-up.

OMSCH is a rare tumor with limited diagnostic accuracy. MRI remains the preferred diagnostic modality, and surgical intervention generally results in favorable outcomes.

Here, we describe a case of a woman with stage IIIC melanoma undergoing intralesional talimogene laherparepvec (T-VEC) therapy who developed a spreading erythematous rash on her left leg, accompanied by fatigue and leg swelling. Skin biopsy revealed recurrent melanoma, with SOX10 and Melan-A positivity, and imaging showed features concerning for multifocal disease recurrence in the left popliteal fossa. This case highlights an unusual presentation of melanoma recurrence and underscores the importance of biopsy in -evaluating new skin findings in patients with a history of melanoma.

Immunohistochemical staining, crucial for characterizing soft-tissue tumor differentiation, revealed diffuse positivity for SOX10 and S100 protein, consistent with a primary nerve sheath tumor rather than metastatic disease. This case highlights the diagnostic challenge posed by FDG-avid lesions in patients with a history of malignancy, underscoring the importance of considering rare differential diagnoses and pursuing tissue diagnosis when imaging is equivocal or clinical presentation deviates from expected metastatic behavior.