Dramatic response of metastatic cutaneous angiosarcoma to an immune checkpoint inhibitor in a patient with xeroderma pigmentosum: whole-genome sequencing aids treatment decision in end-stage disease.

"Mutational signatures" are patterns of mutations that report DNA damage and subsequent repair processes that have occurred. Whole-genome sequencing (WGS) can provide additional information to standard diagnostic techniques and can identify therapeutic targets. A 32-yr-old male with xeroderma pigmentosum developed metastatic angiosarcoma that was unresponsive to three lines of conventional sarcoma therapies. WGS was performed on his primary cancer revealing a hypermutated tumor, including clonal ultraviolet radiation-induced mutational patterns (Signature 7) and subclonal signatures of mutated DNA polymerase epsilon (POLE) (Signature 10). These signatures are associated with response to immune checkpoint blockade. Immunohistochemistry confirmed high PD-L1 expression in metastatic deposits. The anti-PD-1 monoclonal antibody pembrolizumab was commenced off-label given the POLE mutation and high mutational load. After four cycles, there was a significant reduction in his disease with almost complete resolution of the metastatic deposits. This case highlights the importance of WGS in the analysis, interpretation, and treatment of cancers. We anticipate that as WGS becomes integral to the cancer diagnostic pathway, treatments will be stratified to the individual based on their unique genomic and/or transcriptomic profile, enhancing classical approaches of histologically driven treatment decisions

Advanced vulvar apocrine carcinoma expressing estrogen receptors that responds to tamoxifen therapy

Primary vulvar carcinoma is rare and thought to arise from either anogenital mammary-like glands or native apocrine sweat glands. The diagnosis is predominantly based on tumor morphology with supportive evidence from immunohistochemical staining and exclusion of a primary breast carcinoma. The primary modality of treatment is surgery, while optimal managment of advanced disease is unclear. We present the case of a lady who had metastatic recurrent apocrine carcinoma expressing estrogen receptors, who had a complete response assessed by PET-CT scanning after 7 months of tamoxifen therapy. The report includes a discussion of the histological diagnosis and assessment of response to treatment by PET-CT scanning. </jats:p

Loss of CD34 Expression within an Interstitial Dermal Lymphoid Cell Infiltrate Is a Helpful Clue to the Diagnosis of Morphea

A dermal interstitial lymphocytic infiltrate may represent a diagnostic challenge, particularly if the clinical history is not provided. We present three cases within the histological spectrum of morphea in which the immunohistochemical marker CD34 was helpful in confirming the diagnosis

Small-diameter melanoma: Toward a conceptual and practical reappraisal

A recent paper by Torres\u2010Cabala et al.1 published in the JCP reports that about 10% (13/136) of small (3 mm or less in size) dysplastic melanocytic nevi show severe architectural disorder, which, however, is almost never coupled with severe cytologic atypia. It is therefore suggested that, in order to avoid overdiagnosis of melanoma, the significance of architectural changes of small melanocytic lesions must be interpreted with caution; the small size of the lesion hampers the evaluation of some of these criteria (symmetry, confluence of junctional nests and degree of single cell proliferation)

Tiger-like mycosis fungoides: an unusual clinical presentation of a rare variant of mycosis fungoides.

Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma. Mycosis fungoides classically presents in the skin as patches, plaques, tumors, or erythroderma, progressing to involve the lymph nodes and peripheral blood. The many clinical variants, with different histologic patterns, and the subtle early clinical and histologic changes may delay early diagnosis and present a diagnostic challenge for clinicians. The greatest challenge in diagnosis is the pre-mycotic stage, which may closely resemble eczematous or psoriasiform dermatitis clinically and histologically. The persistence of lesions and inadequate response to treatment are the first warning signs. Later stages of MF have a poor prognosis with poor therapeutic response and fatal outcome. We describe a 72-year-old man, who presented with a two-year history of an unusual eruption, which started on the abdomen, around the waistline, and gradually spread to involve his back, trunk, and buttocks. Clinically, the skin eruption presented as tiger-like stripes. The diagnosis was confirmed after histopathologic examination. The patient was treated with NB-UVB phototherapy with marked improvement