Stenotrophomonas maltophilia skin infection in an immunocompetent patient: Primary cutaneous CD30+ T-cell lymphoproliferative disorder or pseudolymphoma?

Cutaneous pseudolymphomas are a wide group of diseases mimicking cutaneous lymphoma. They comprise several skin conditions with different etiopathogenesis, clinical-pathological features, and prognosis, which may occur in the absence of an identifiable trigger factor or after administration of medications or vaccinations, tattoos, infections, or arthropod bites. They present with different manifestations: from solitary to regionally clustered lesions, up to generalized distribution and, in rare cases, erythroderma. They persist variably, from weeks to years, and resolve spontaneously or after antibiotics, but may recur in some cases. CD30+ T-cell pseudolymphomas are characterized by the presence of large, activated lymphoid cells, generally in response to viral infections, arthropod assault reactions, and drug eruptions. Stenotrophomonas maltophilia is a ubiquitous Gram-negative bacillus responsible for opportunistic infections in immunocompromised patients. Infection of intact skin in immunocompetent patients is particularly rare. Here, we report a case of a man presenting an isolated nodule histopathologically mimicking a primary cutaneous CD30+ T-cell lymphoproliferative disorder.

Cutaneous B cell pseudolymphoma treated with rituximab and methotrexate.

Cutaneous B cell pseudolymphoma (CBPL), or cutaneous lymphoid hyperplasia, is the most common pseudolymphoma. It typically responds well to local treatment and follows a benign course. Herein, we describe the unique case of a patient with CBPL that was refractory to a variety of treatments, with subsequent response to rituximab followed by methotrexate. This case explores the complex interplay of T and B lymphocytes, and the potential role of perifollicular T cells in treatment resistant CBPL. Further, it describes the additive therapeutic effect of rituximab and methotrexate to target both B cell and T cell populations in CBPL, a strategy already employed in a number of other conditions.

Recurrent episodes of palpable migratory arciform erythema associated with IVIg infusions.

Palpable migratory arciform erythema (PMAE) is an uncommon T cell pseudolymphoma characterized by erythematous, annular-to-arciform papules and plaques. Although the eruption is self-limited in most cases, recurrences are routine. Diagnosis requires attention to clinical history as well as histopathologic analysis, which allow for differentiation from other T cell pseudolymphomas and gyrate erythemas. A common triggering factor has not been identified. We report a 60-year-old man who developed PMAE after IVIg infusion. Interestingly, although the individual eruptions were self-limited and resolved after several weeks, subsequent infusions predictably resulted in recurrence of PMAE, confirming the association. To our knowledge, this is the first reported case of recurrent PMAE in association with IVIg infusions.

Pseudolymphomatous Atypical Fibroxanthoma.

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.

Macrophagic myofasciitis and subcutaneous pseudolymphoma caused by aluminium adjuvants.

Aluminium hydroxide is a well-known adjuvant used in vaccines. Although it can enhance an adaptive immune response to a co-administered antigen, it causes adverse effects, including macrophagic myofasciitis (MMF), subcutaneous pseudolymphoma, and drug hypersensitivity. The object of this study is to demonstrate pediatric cases of aluminium hydroxide-induced diseases focusing on its rarity, under-recognition, and distinctive pathology. Seven child patients with biopsy-proven MMF were retrieved from the Seoul National University Hospital (SNUH) pathology archives from 2015 to 2019. The medical records and immunisation history were reviewed, and a full pathological muscle examination was carried out. The mean age was 1.7 years (8.9-40 months), who had records of vaccination against hepatitis B, hepatitis A, and tetanus toxoid on the quadriceps muscle. The chief complaints were muscle weakness (n = 6), delayed motor milestones (n = 6), instability, dysarthria, and involuntary movement (n = 1), swallowing difficulty (n = 1), high myopia (n = 1), and palpable subcutaneous nodules with skin papules (n = 1). Muscle biopsy showed MMF (n = 6) and pseudolymphoma (n = 1) with pathognomic basophilic large macrophage infiltration, which had distinctive spiculated inclusions on electron microscopy. The intracytoplasmic aluminium was positive for PAS and Morin stains. Distinctive pathology and ultrastructure suggested an association with aluminium hydroxide-containing vaccines. To avoid misdiagnosis and mistreatment, we must further investigate this uncommon condition, and pharmaceutical companies should attempt to formulate better adjuvants that do not cause such adverse effects.

Lupus Erythematosus Tumidus with Pseudolymphomatous Infiltrates: A Case Report.

A 39-year-old Japanese woman presented with a pruritic infiltrated erythematous plaque on the right cheek. Histopathologic analysis of the erythema showed dermal edema, separation of collagen bundles, and nodular perivascular and periadnexal infiltration of lymphocytes in the whole dermis, without epidermal changes. Alcian blue staining intensity was elevated between the collagen bundles, indicating dermal mucinosis. The nodular infiltrates consisted of CD3+ T cell clusters and CD20+ B cell clusters (ratio, approximately 3:1) and included numerous CD123+ cells, indicative of plasmacytoid dendritic cells. Blood analysis revealed serum antinuclear antibody at a titer of 1:160 (homogeneous, speckled pattern). Lupus erythematosus tumidus with pseudolymphomatous infiltrates was diagnosed. Hydroxychloroquine treatment partially improved symptoms; however, the addition of prednisolone was required for complete resolution. Lupus erythematosus tumidus is sometimes accompanied by pseudolymphomatous infiltrates. Dermal mucinosis and the presence of numerous plasmacytoid dendritic cells are useful in differentiating lupus erythematosus tumidus from pseudolymphoma.

Idiopathic inflammatory diseases of orbit and ocular adnexa: Histopathological and immunochemical analysis.

Purpose: : To present histopathological and immunohistochemical analysis of idiopathic inflammatory diseases of orbit and ocular adnexa. Methods: Design- A retrospective laboratory-based study. The study was carried out in an ocular pathology laboratory in a tertiary institute of northeast India where analysis of 93 cases was done in 5 years, during the period from 2011 to 2016. Hematoxylin--eosin and special stains were done for the diagnoses. Immunohistochemistry (IHC) panel was also carried out. For infectious pathology, Grocott's methenamine silver (GMS) stain for fungus, tissue Gram's stain for bacteria's, and acid-fast stains for tubercular bacilli were done. IHC panels were done for CD 20 (B-cells), CD-3 (T-cells), CD-45 (Leukocyte common antigen, LCA), BCL-2, CD-138 (Plasma cells), Kappa, Lambda, IgG-4 in tissue, IgG-4 in serum, etc. IHCs were done using kit methods (standardized) and adequate controls were taken for each sample. Results: 93 cases of nonspecific orbital inflammation were reported out of 1,467 specimens. Orbital pseudotumors (idiopathic orbital inflammatory disease, IOID) were seen in 27 cases (sclerosing variety-6); benign lymphoid hyperplasia in two cases; reactive lymphoid hyperplasia in 10 cases; atypical plasma lymphoproliferative reactive (polyclonal immunophenotypically, IgG4 negative) lesions in four cases; IgG-4 related disease in one case; nonspecific inflammatory reactions (conjunctiva, sclera, and lid) in 49 cases. In all the diagnoses, infections and lymphomas were excluded. Conclusion: Biopsy supported study on nonspecific orbital inflammation was important to know the pattern.

T-cell pseudolymphoma in recurrent herpes simplex virus infection.

BACKGROUND: In cases of herpes virus infection without typical histologic (and clinical) signs it is difficult to achieve the correct diagnosis by histology alone. Some of those cases are prone to be misdiagnosed as cutaneous lymphoma. METHODS: This retrospective study included five patients with herpes simplex virus (HSV)-associated pseudolymphoma. We investigated clinical, histomorphologic and immunophenotypic features of all patients. RESULTS: All biopsy specimens presented a superficial and deep perivascular lymphohistiocytic infiltrate with epidermotropism, atypia and admixed plasma cells to varying degrees. Four of five samples showed lining-up of lymphocytes in the junctional zone with predominance of CD8+ lymphocytes, in contrast to the dermal part (inverse CD8:CD4 ratio). Papillary edema was found in four of five cases. Clinically, patchy erythema located on the buttocks and adjacent areas was typical, sometimes with erosions and crusts. Medical history of recurrent blisters, pain or itching was additionally helpful. CONCLUSION: We point out subtle but consistent histomorphologic criteria, which were helpful to diagnose HSV-associated pseudolymphoma in context with the clinical presentation.

CD8-positive pseudolymphoma in lues maligna and human immunodeficiency virus with monoclonal T-cell receptor-beta rearrangement.

A 42-year-old Caucasian man suffered from disseminated plaques and ulcerated nodules for 6 weeks. He had weight loss and generalized lymphadenopathy. Underlying diseases were not known up till then. Based on a skin biopsy, the diagnosis of CD8-positive cutaneous T-cell lymphoma, type mycosis fungoides was made in a pathological reference center for lymphoma. A reproducible T-cell receptor (TCR)-beta rearrangement was detectable. Before starting therapy, a new biopsy was taken and the previous diagnosis was re-evaluated taking clinical images and symptoms into account. Based on both, the diagnosis of a CD8+ pseudolymphoma in lues maligna and human immunodeficiency virus was made. We highlight histopathologic clues for the correct diagnosis, and we emphasize the indispensability of clinical-pathological correlation. Furthermore, we discuss the differential diagnosis of CD8+ lymphoproliferative disorders.

Cutaneous intravascular CD30+ T-cell pseudolymphoma occurring in a regressing keratoacanthoma.

Cutaneous intravascular CD30+ pseudolymphoma is an uncommon incidental finding that may mimic intravascular or angiotropic lymphoma. We describe a 78-year-old female with a traumatized regressing keratoacanthoma on her left cheek. A shave biopsy revealed intravascular staining of atypical lymphocytes positive for CD45, CD3 and CD30. Clinical exam revealed no other evidence of lymphoma, the patient denied constitutional symptoms, and routine blood work was normal. The patient is healthy and doing well 28 months after her first visit. CD30+ pseudolymphoma should be distinguished from malignant intravascular lymphoproliferative disorders.

Mixed Lichenoid and Follicular T- and B-Cell Lymphoid Reaction to Red Tattoos With Monoclonal T Cells.

Pseudolymphomatous reactions have been described to occur in tattoos. Most cases have exhibited T-cell predominance and polyclonal T-cell receptor gene rearrangements. One case with monoclonal IgH gene rearrangements progressed into B-cell lymphoma. Lichenoid infiltrates are commonly described but lymphoid follicles much less frequently. We report a case with mixed lichenoid and follicular T- and B-cell reaction to red tattoos. The histopathology and the immunohistochemical studies were constant with a mixed T- and B-cell pseudolymphoma, the IgH gene rearrangement study was polyclonal, but the T-cell receptor gene rearrangement study was monoclonal. The patient who responded to intralesional corticosteroid injections remains under close scrutiny.

Red tattoo-related mycosis fungoides-like CD8+ pseudolymphoma.

Cutaneous reactions to red tattoo pigment rarely manifest as pseudolymphomatous reactions. We describe an exceedingly rare case of red tattoo-related T-cell predominant pseudolymphoma microscopically mimicking mycosis fungoides. Careful clinicopathological correlation was required to obtain the correct diagnosis and aid in an effective treatment course.

Treatment of Cutaneous Pseudolymphoma: A Systematic Review.

Cutaneous pseudolymphoma (CPL) is a reactive polyclonal T- or B-cell lymphoproliferative process. CPL may appear as localized or disseminated skin lesions. While most cases of CPL are idiopathic, they may also occur as a response to, for example, contact dermatitis, arthropod reactions, and bacterial infections. CPL can be classified based on its clinical features, but all variants have similar histopathological patterns of either predominantly B-cell infiltrates, T-cell infiltrates, or mixed T/B-cell infiltrates. The prognosis of CPL is good, but the underlying disease process should be taken into account. If an antigenic stimulus is identified, it should be removed. In patients with idiopathic CPL, a close follow-up control strategy should be adopted. The aim of this systematic review is to summarize all reported treatments for CPL. The review was based on articles from the PubMed database, using the query "skin pseudolymphoma treatment", English and German, about "human" subjects, and published between 1990 and 2015 documenting adequate treatment and/or aetiology. Mainly individual case reports and small case series were found. Treatment options include topical and intralesional agents, systemic agents, and physical modalities. The final part of the review proposes a treatment algorithm for CPL according to each aetiology, based on the literature of the last 25 years. Future research should focus on randomized controlled trials and studies on long-term outcomes, which were not identified in the current review.

No definite clinical features of immunoglobulin G4-related disease in patients with pulmonary nodular lymphoid hyperplasia.

Pulmonary nodular lymphoid hyperplasia (PNLH) may show heavy lymphoplasmacytic infiltrates with increased immunoglobulin G4 (IgG4)-positive plasma cells as in IgG4-related disease (IgG4-RD). However, it is unclear whether PNLH could be a manifestation of IgG4-RD. A recent study reported the presence of Epstein-Barr virus (EBV) in IgG4-related lymphadenopathy. We postulated that a subset of PNLH might represent IgG4-related lung disease with EBV-positive lymphocytes as has been reported in IgG4-related lymphadenopathy. IgG and IgG4 immunohistochemistries were performed on 26 PNLH cases in our files (1994-2014) and on 9 controls including diffuse lymphoid hyperplasia of the lung without nodularity (n=2), usual interstitial pneumonia with increased lymphoplasmacytic infiltrates (n=5), and thoracic lymphadenopathy (n=2). EBV in situ hybridization was performed in the cases with the highest IgG4+ count (n=15). Median IgG4+ plasma cell count in PNLH was 36 cells per high-power field (interquartile range, 7-65) with median IgG4+/IgG+ ratio of 0.24 (interquartile range, 0.12-0.37). Three of 26 cases had a markedly increased IgG4+ count (range, 55-139) and IgG4+/IgG+ ratio (>0.4). Serum IgG4 level available in 1 of these cases was not elevated, and all 3 patients had alternate medical diagnoses. Absolute counts of IgG4+ plasma cells in PNLH did not significantly differ from the other control groups. Result of EBV in situ hybridization was negative in all cases tested. In conclusion, most PNLH cases had low IgG4+ cells, and there was no clinical evidence of IgG4-RD or EBV among those with increased IgG4+ cells.

Lymphocytic Interstitial Pneumonia.

Lymphocytic interstitial pneumonia (LIP) is a rare lung disease on the spectrum of benign pulmonary lymphoproliferative disorders. LIP is frequently associated with connective tissue diseases or infections. Idiopathic LIP is rare; every attempt must be made to diagnose underlying conditions when LIP is diagnosed. Computed tomography of the chest in patients with LIP may reveal ground-glass opacities, centrilobular and subpleural nodules, and randomly distributed thin-walled cysts. Demonstrating polyclonality with immunohistochemistry is the key to differentiating LIP from lymphoma. The 5-year mortality remains between 33% and 50% and is likely to vary based on the underlying disease process.

Borrelial Lymphocytoma in Children.

BACKGROUND: The aim of this study was to investigate demographic features, clinical characteristics, laboratory findings and posttreatment course of the disease in children with borrelial lymphocytoma (BL). METHODS: Between 2008 and 2014, we prospectively studied 33 children younger than 15 years with untreated BL. Data on demographic and clinical features were collected by means of a questionnaire. Serological testing and Lyme borrelia blood cultures were performed. All patients were treated with recommended antibiotics. Patients were followed up at least 3 months after inclusion into the study. RESULTS: Twenty-two boys and 11 girls, aged 2-13 (median, 5.5) years, fulfilled the inclusion criteria. A tick bite at the site of BL was recalled by 30%. The median incubation period was 10.5 (range, 1-38) days. The median duration of BL before the initial examination was 10 (range, 0-270) days. In 88% of patients, BL was localized on ear lobe. The color/shape of BL was more often red (73%) and puffy (91%). Median size was 1.5 (range, 0.5-3) cm. The initial disease was mild in 82%. Associated symptoms were reported in 36% of patients. Concomitant solitary erythema migrans and meningitis were detected in 9% and 3% of patients, respectively. Serum borrelial antibodies were present in 40% of patients. In 7%, Borrelia afzelii was isolated from blood. Posttreatment course of the disease revealed the median duration of BL and systemic symptoms for 16 (range, 2-46) and 15 (range, 3-40) days, respectively. CONCLUSIONS: BL in children, treated with recommended antibiotics, is a mild disease with a good prognosis.