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Journal of Cutaneous Pathology Jan 2020Cutaneous pseudolymphomas (PSLs) belong to a group of lymphocytic infiltrates that histopathologically and/or clinically simulate lymphomas. Different causative agents... (Review)
Review
Cutaneous pseudolymphomas (PSLs) belong to a group of lymphocytic infiltrates that histopathologically and/or clinically simulate lymphomas. Different causative agents (e.g., Borrelia sp., injected substances, tattoo, arthropod bite) have been described, but in many cases no cause can be identified, hence the term idiopathic PSL. Clinicopathological correlation is important to make the diagnosis. Four main groups of cutaneous PSL can be distinguished based on histopathologic and/or clinical presentation: (a) nodular PSL; (b) pseudo-mycosis fungoides (pseudo-MF) and simulators of other CTCLs; (c) other PSL (representing distinct clinical entities); and (d) intravascular PSL. This article gives an overview of the histopathologic and clinical characteristics of cutaneous PSLs and proposes a new classification.
Topics: Borrelia; Borrelia Infections; Humans; Pseudolymphoma; Skin Neoplasms; Tattooing
PubMed: 31237707
DOI: 10.1111/cup.13532 -
Deutsches Arzteblatt International May 2022
Topics: Anti-Bacterial Agents; Humans; Lyme Disease; Pseudolymphoma
PubMed: 36017988
DOI: 10.3238/arztebl.m2022.0015 -
Dermatology Online Journal May 2020Pseudolymphomatous folliculitis is a benign entity that is included within pseudolymphomas. Because of its rapid clinical growth and suspicious histology it has to be...
Pseudolymphomatous folliculitis is a benign entity that is included within pseudolymphomas. Because of its rapid clinical growth and suspicious histology it has to be differentiated from malignant entities. Given its low frequency, the dermatoscopic characteristics of this entity are not well-characterized and have been described only once previously. We present a middle-aged woman with a facial erythematous plaque of 6 months' evolution, with dermatoscopy in which follicular plugs on an erythematous base were appreciated. The histology showed a dense lymphocytic infiltrate with folliculotropism and follicular alteration, with numerous peripheral histiocytes positive for S100 and CD1a. The lesion partially disappeared after the biopsy, and completely after topical treatment.
Topics: Adult; Dermoscopy; Diagnosis, Differential; Female; Folliculitis; Humans; Middle Aged; Pseudolymphoma; Skin; Skin Diseases
PubMed: 32621704
DOI: No ID Found -
Indian Dermatology Online Journal 2022In dermatology, "pseudo" is often used as a prefix for entities resembling another standard condition, either morphologically or histopathologically. Correspondingly,...
In dermatology, "pseudo" is often used as a prefix for entities resembling another standard condition, either morphologically or histopathologically. Correspondingly, "pseudotumor" is a term encompassing dermatological conditions which are not true proliferations, but either have a clinical resemblance to a known tumor (, Pseudokaposi's sarcoma is actually a non-neoplastic condition) or a histopathological resemblance to one (, pseudo-myogenic hemangioendothelioma named due to a histopathological resemblance between myocytes and tumor cells). Often such a nomenclature can create confusion and unnecessary alarm for both the physicians and the patients. Through this article we attempt to summarise "pseudotumors" in dermatology and classify them into clinical and histopathological "pseudotumors", so as to produce a ready reckoner for this confusing nomenclature.
PubMed: 35287424
DOI: 10.4103/idoj.idoj_226_21 -
Dermatologie (Heidelberg, Germany) Apr 2023
Topics: Humans; Pseudolymphoma; Borrelia
PubMed: 36977839
DOI: 10.1007/s00105-023-05133-6 -
Journal of Cutaneous Pathology Oct 2022Cutaneous lymphoid hyperplasia (CLH), also known as cutaneous pseudolymphoma, is a spectrum of benign conditions characterized by reactive B- and T-cell cutaneous... (Review)
Review
Cutaneous lymphoid hyperplasia (CLH), also known as cutaneous pseudolymphoma, is a spectrum of benign conditions characterized by reactive B- and T-cell cutaneous lymphocytic infiltrates. B-cell lymphoid proliferations are a heterogenous group of non-neoplastic cutaneous diseases that must be histopathologically distinguished from cutaneous B-cell lymphomas. These proliferations can be observed as reactive phenomena to infections, medications, allergens, neoplasms, and more. Furthermore, there are many inflammatory conditions that present with reactive B-cell infiltrates, including actinic prurigo, Zoon balanitis, Rosai-Dorfman disease, and cutaneous plasmacytosis. This review summarizes multiple cutaneous B-cell lymphoid proliferations within the major categories of reactive and disease-associated CLH. Further we discuss major discriminating features of atypical CLH and malignancy. Understanding the specific patterns of B-cell CLH is essential for the proper diagnosis and treatment of patients presenting with such lesions.
Topics: B-Lymphocytes; Diagnosis, Differential; Humans; Hyperplasia; Lymphoma, B-Cell; Male; Pseudolymphoma; Skin; Skin Neoplasms
PubMed: 35656820
DOI: 10.1111/cup.14264 -
Indian Journal of Dermatology 2022
PubMed: 36998855
DOI: 10.4103/ijd.ijd_518_22 -
Alpha Psychiatry Jan 2023
PubMed: 36879993
DOI: 10.5152/alphapsychiatry.2023.221037 -
The American Journal of Dermatopathology Dec 2020Atypical fibroxanthoma is a rare mesenchymal skin tumor of intermediate malignancy that typically occurs on sun-damaged skin of elderly patients. Histologically, it is...
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.
Topics: Aged, 80 and over; Biomarkers, Tumor; Biopsy; Diagnosis, Differential; Gene Rearrangement, T-Lymphocyte; Genes, Immunoglobulin Heavy Chain; Genes, T-Cell Receptor; Humans; Immunohistochemistry; Male; Neoplasms, Fibrous Tissue; Polymerase Chain Reaction; Predictive Value of Tests; Pseudolymphoma; Skin Neoplasms
PubMed: 32769551
DOI: 10.1097/DAD.0000000000001761 -
Journal of Neuroinflammation Jul 2023Immune inflammatory responses play an important role in spinal cord injury (SCI); however, the beneficial and detrimental effects remain controversial. Many studies have...
BACKGROUND
Immune inflammatory responses play an important role in spinal cord injury (SCI); however, the beneficial and detrimental effects remain controversial. Many studies have described the role of neutrophils, macrophages, and T lymphocytes in immune inflammatory responses after SCI, although little is known about the role of B lymphocytes, and immunosuppression can easily occur after SCI.
METHODS
A mouse model of SCI was established, and HE staining and Nissl staining were performed to observe the pathological changes. The size and morphology of the spleen were examined, and the effects of SCI on spleen function and B cell levels were detected by flow cytometry and ELISA. To explore the specific mechanism of immunosuppression after SCI, B cells from the spleens of SCI model mice were isolated using magnetic beads and analyzed by 4D label-free quantitative proteomics. The level of inflammatory cytokines and iron ions were measured, and the expression of proteins related to the Tom20 pathway was quantified by western blotting. To clarify the relationship between iron ions and B cell pyroptosis after SCI, we used FeSO and CCCP, which induce oxidative stress to stimulate SCI, to interfere with B cell processes. siRNA transfection to knock down Tom20 (Tom20-KD) in B cells and human B lymphocytoma cell was used to verify the key role of Tom20. To further explore the effect of iron ions on SCI, we used deferoxamine (DFO) and iron dextran (ID) to interfere with SCI processes in mice. The level of iron ions in splenic B cells and the expression of proteins related to the Tom20-Bax-caspase-gasdermin E (GSDME) pathway were analyzed.
RESULTS
SCI could damage spleen function and lead to a decrease in B cell levels; SCI upregulated the expression of Tom20 protein in the mitochondria of B cells; SCI could regulate the concentration of iron ions and activate the Tom20-Bax-caspase-GSDME pathway to induce B cell pyroptosis. Iron ions aggravated CCCP-induced B cell pyroptosis and human B lymphocytoma pyroptosis by activating the Tom20-Bax-caspase-GSDME pathway. DFO could reduce inflammation and promote repair after SCI by inhibiting Tom20-Bax-caspase-GSDME-induced B cell pyroptosis.
CONCLUSIONS
Iron overload activates the Tom20-Bax-caspase-GSDME pathway after SCI, induces B cell pyroptosis, promotes inflammation, and aggravates the changes caused by SCI. This may represent a novel mechanism through which the immune inflammatory response is induced after SCI and may provide a new key target for the treatment of SCI.
Topics: Animals; Humans; Mice; B-Lymphocytes; bcl-2-Associated X Protein; Carbonyl Cyanide m-Chlorophenyl Hydrazone; Caspases; Gasdermins; Inflammation; Iron; Pseudolymphoma; Pyroptosis; Spinal Cord Injuries
PubMed: 37480037
DOI: 10.1186/s12974-023-02848-0