ABSTRACT
Atypical fibroxanthoma is a rare mesenchymal skin tumor of intermediate malignancy that typically occurs on sun-damaged skin of elderly patients. Histologically, it is composed of pleomorphic cells with hyperchromatic nuclei and abundant cytoplasm, commonly arranged in a spindle cell pattern. Different histologic variants have been described during the past years. We present a case of atypical fibroxanthoma containing a dense inflammatory infiltrate, which in conjunction with the existence of immunoblast-like and Reed-Sternberg-like neoplastic cells could be misinterpreted as a lymphoid neoplasm. Immunohistochemical studies revealed strong positivity of tumor cells for CD10 and negativity for cytokeratins, p63, p40, S100, SOX10, ERG, actin, desmin, B and T-cell markers, BCL6, CD15, and CD30. The inflammatory infiltrate contained a mixed reactive T- and B-cell population with negative T-cell receptor and immunoglobulin heavy rearrangements. We discuss the differential diagnosis of this entity in which clinical, immunohistochemical, and molecular features are essential to avoid the diagnosis of a lymphoproliferative disease.
Subject(s)
Neoplasms, Fibrous Tissue/pathology , Pseudolymphoma/pathology , Skin Neoplasms/pathology , Aged, 80 and over , Biomarkers, Tumor/analysis , Biomarkers, Tumor/genetics , Biopsy , Diagnosis, Differential , Gene Rearrangement, T-Lymphocyte , Genes, Immunoglobulin Heavy Chain , Genes, T-Cell Receptor , Humans , Immunohistochemistry , Male , Neoplasms, Fibrous Tissue/genetics , Neoplasms, Fibrous Tissue/immunology , Polymerase Chain Reaction , Predictive Value of Tests , Pseudolymphoma/genetics , Pseudolymphoma/immunology , Skin Neoplasms/genetics , Skin Neoplasms/immunologyABSTRACT
Las pustulosis amicrobianas hacen referencia a un grupo de entidades con multitud de pústulas estériles, de inicio agudo y resolución rápida y autolimitada, localizadas en cara y flexuras de forma simétrica y que suelen relacionarse con la ingesta de fármacos o infecciones, predominantemente víricas. Se presentan dos casos de pustulosis aguda exantemática generalizada, en dos pacientes sin antecedentes personales ni familiares de psoriasis. Las lesiones aparecieron de forma súbita tras la ingesta de distintos medicamentos. El cuadro se resolvió rápida y espontáneamente, sin repercusión en el estado general, ni recurrencia posterior. En el estudio histopatológico se objetivó la presencia de pústulas parafoliculares, con fenómenos de perivasculitis en dermis superficial. El cultivo microbiológico de las pústulas fue negativo para gérmenes patógenos (AU)
