Spindle-cell B-cell lymphoma presenting in the skin

Recent advances in cutaneous lymphoma-implications for current and future classifications

The Revised European-American Classification of mature lymphoid neoplasms published in 1994 and the 2001, 2008 and 2016 WHO classifications that followed, were the product of international collaboration and consensus amongst haematopathologists, geneticists, molecular scientists and clinicians. Primary cutaneous lymphomas were fully incorporated into this process following the publication of the WHO-EORTC classification of cutaneous lymphomas in 2005. The definition, diagnostic criteria and recommended studies for primary cutaneous lymphoma continue to be refined. The 2022 International Consensus Classification represents the most recent update and an overview of all the main entities presenting primarily in the skin, together with the major changes in classification, are summarized herein. Primary cutaneous marginal zone lymphoma is segregated from other extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT lymphoma) and downgraded to a lymphoproliferative disorder in line with its markedly indolent behaviour. In addition, two subtypes are recognised, based largely but not exclusively on whether they are heavy chain class-switched or IgM positive. Similarly, in keeping with a trend to greater conservatism, primary cutaneous acral CD8 positive T cell lymphoma is now also classified as a lymphoproliferative disorder. In addition, significant new insights into the biology of primary cutaneous lymphoma have also recently been forthcoming and will be presented. These studies have enhanced our knowledge of genetic, epigenetic and transcriptional changes in this group of diseases. They not only identify potential targets for novel therapies, but also raise as yet unanswered questions as to how we categorise cutaneous lymphomas, particularly with respect to relationships with similar lymphomas at extracutaneous sites.

Spindle-cell (Sarcomatoid) Variant of Cutaneous Anaplastic Large-cell Lymphoma (C-ALCL): An Unusual Mimicker of Cutaneous Malignant Mesenchymal Tumors-A Series of 11 Cases

Cutaneous anaplastic large-cell lymphoma (C-ALCL) represents one of the entities within the group of CD30-positive lymphoproliferative disorders of the skin. Most cases are ALK-negative, though isolated cases of ALK-positive C-ALCL have also been reported. By definition, the diagnosis of C-ALCL requires the expression of CD30 in >75% of the cells. Histopathologically, C-ALCL shows a dermal-based nodular and circumscribed proliferation of large pleomorphic cells with vesicular nuclei, prominent nucleoli, and eosinophilic cytoplasm, including hallmark cells. Since 1990, isolated case reports of a so-called "sarcomatoid" variant have been published in the literature. Herein, we present a series of 11 cases of spindle (sarcomatoid) C-ALCL, with comprehensive histopathologic, immunophenotypic, and molecular data. Spindle C-ALCL represents a potential mimicker of malignant mesenchymal or hematopoietic tumors in the skin and should always be considered in the differential diagnosis when assessing cutaneous pleomorphic spindle cell neoplasms.

Two cases of spindle cell variant diffuse large B-cell lymphoma of the uterine cervix

Lymphoma with prominent spindle cell features is a morphological variant of diffuse large B-cell lymphoma (DLBCL) and is categorized as a rare variant by the WHO classification. Most cases arise from the skin, with only two cases reported in the uterine cervix to date. Here, we report two cases of spindle cell variant DLBCL of the uterine cervix. Although these cases might be rare, we believe that, as gynecologists and pathologists increase their knowledge of this variant type, more cases will be diagnosed properly.

Primary cutaneous B-cell lymphomas with large cell predominance-primary cutaneous follicle center lymphoma, diffuse large B-cell lymphoma, leg type and intravascular large B-cell lymphoma

In this review, we present clinical features and detailed histopathologic, immunologic, and molecular information regarding primary cutaneous follicle center lymphoma and primary cutaneous diffuse large B-cell lymphoma, leg type which together represent two of the three most common types of primary cutaneous B-cell lymphoma recognized in the current WHO classification system.^1,2 Overall, B-cell lymphomas represent 19-27% of primary cutaneous lymphomas in most large European and American studies^3-6 and together, primary cutaneous follicle center lymphoma and primary cutaneous diffuse large B-cell lymphoma, leg type account for approximately 2/3 to ¾ of these cases.^5,7-11 Both subtypes can contain a high content of large B-lymphocytes, although most cases of primary cutaneous follicle center lymphomas exhibit a range in cell size and cytology. Intravascular large B-cell lymphoma, a less commonly-encountered EBV-negative primary cutaneous B-cell lymphoma composed of large cells, will be more briefly discussed in this report as well.

A rare spindle-cell variant of non-Hodgkin's lymphoma of the mandible

A 64-year-old male farmer presented with a rapidly progressive swelling of the left mandible since 6 months. The swelling was firm to hard, diffuse, nontender, obliterating the vestibule with paresthesia of lower lip. The cone beam computed tomography imaging revealed an ill-defined, moth-eaten radiolucency with destruction of the buccal and lingual cortical plates. The rapid growth and aggressive behavior of the lesion coupled with guidance from the patient's previous reports from the incisional biopsy and fine needle aspiration cytology warranted a mandibular resection. Microscopic examination showed an encapsulated lesion situated in the connective tissue containing a mixture of proliferating spindle-shaped cells arranged in fascicles and round cells infiltrating into the connective tissue stroma and bone. The neoplastic cells exhibited atypical features such as pleomorphism, hyperchromatism and increased mitotic figures with noncleaved nuclei. A working diagnosis of a spindle-cell sarcoma was arrived at with various differentials provided such as fibrosarcoma, rhabdomyosarcoma, leiomyosarcoma, malignant peripheral nerve sheath tumor, Langerhans cell histiocytosis and lymphoma and stating the need for immunohistochemistry to subtype the tumor. The neoplastic cells were negative for Van Gieson's stain and Masson's trichrome. Immunohistochemical analysis performed using desmin, smooth muscle actin, S-100 and CD1a in a bid to determine the phenotype of the tumor and rule out the previously stated differentials were all negative for the lesion. Lymphoid markers such as leukocyte common antigen and CD20 (cluster differentiation marker for B-cells) showed positivity in spindle-shaped cells as well as round cells indicating the tumor to be a lymphoproliferative lesion of B-cell type. A final diagnosis of “spindle-cell variant of non-Hodgkin's lymphoma” was rendered based on the immunohistochemical profile.

A spindle cell variant of diffuse large B-cell lymphoma is characterized by T-cell/myofibrohistio-rich stromal alterations: analysis of 10 cases and a review of the literature

Spindle-shaped diffuse large B-cell lymphoma (Sp-DLBCL) has been recognized as a rare morphologic variant of DLBCL. However, the biological processes that contribute to the specific features of Sp-DLBCL remain poorly understood. In this study, a combined immunophenotypic and genetic analysis was performed in 10 Sp-DLBCL. First, we investigated several unique markers for anaplasia (CD30, ALK, CD68, and EBER-ISH), mesenchyma (SMA, desmin, and vimentin), and B-cell differentiation (CD10, BCL6, and MUM1). We also performed conventional cytogenetic and fluorescence in situ hybridization studies to look for common chromosomal break points (BCL2, BCL6, and MYC). We found that most Sp-DLBCLs were germinal center B cell-like and that none had any other specific phenotypes or any karyotypic abnormalities. Instead, T cells, CD68-positive macrophages and SMA-positive myofibroblasts were significantly increased in Sp-DLBCL when compared with conventional GCB origin DLBCL cases (n = 10) (P = 0.012, P < 0.001, and P < 0.0001, respectively). To further characterize Sp-DLBCL, we next compared the expression of fibroblast growth factor 2 (FGF2) and transforming growth factor-β1 (TGFβ1) between the two types of DLBCL. Finally, we confirmed that the number of FGF2- and TGFβ1-positive stromal cells was markedly increased in Sp-DLBCL and that the difference between these and conventional GCB origin DLBCLs was significant (P < 0.0001 and P = 0.0017, respectively). Thus, T-cell/myofibrohistio-rich stromal alterations in Sp-DLBCL, especially those mediated by TGFβ1 and FGF2, may play a role in the transition of lymphoma cells into those with spindle-shaped features.

Cutaneous Sarcomatoid B-Cell Lymphoma

A rare case of a spindle cell (sarcomatoid) B-cell lymphoma is described. The patient, a 48-year-old male, presented with a several month history of an enlarging lesion on the scalp. Although there have been a few recent reports of cutaneous sarcomatoid lymphomas, this case is especially unusual because it presented as a scarlike plaque rather than a tumor and microscopically exhibited a prominent myxoid matrix. Given these features, the lesion was initially interpreted as an atypical fibromucinosis. The differential diagnosis included fibromucinous lesion consistent with variant of lichen myxedematosus, spindle cell carcinoma, spindle cell melanoma, atypical fibroxanthoma, and atypical smooth muscle tumors. Initial immunoperoxidase studies demonstrated negative staining for CD68, factor XIIIa, CD57, cytokeratin(AE1/AE3), S100, EMA, and vimentin, essentially ruling out the previously mentioned neoplasms. Subsequently, strong positive staining for LCA(CD45RB) and CD20 was demonstrated characteristic of a B-cell lymphoma. The patient underwent local radiotherapy with complete resolution. Although all variants of cutaneous sarcomatoid B-cell lymphomas are rare, it is imperative to consider them in the differential diagnosis of otherwise difficult to categorize spindle cell proliferations. This includes neoplasms and, based on the current case, fibromucinoses as well.

Primary hepatic lymphoma with spindle cell components: a case report

Diffuse large B-cell lymphoma (DLBCL) with spindle cell components is extremely rare and often misdiagnosed as carcinoma or sarcoma. Here, we present a case of primary DLBCL with spindle cell components arising in the liver, for which a preoperative diagnosis by needle biopsies was unsuccessful. The patient was a 70-year-old man with a continuous cough. Thoracic computed tomography incidentally detected a mass of 5 cm in diameter in his liver. The initial and second needle biopsies from the liver mass were pathologically diagnosed as suspicious for sarcomatoid hepatocellular carcinoma. He underwent an extended left hepatectomy. Histological examination revealed a diffuse or epithelioid arrangement of round and polygonal cells, mixed with the fascicles of spindle-shaped cells. Immunohistochemically, all the morphological types of tumor cells showed positive reactions for a lymphocytic marker (CD45RB) and B-cell markers (CD20 and CD79a). Double-immunostaining revealed that the spindle-shaped tumor cells expressed CD20, but never expressed alpha-smooth muscle actin. Malignant lymphoma with a spindle cell morphology is quite uncommon, and this variant can be a diagnostic pitfall, especially in tiny biopsy specimens. We emphasize that pathologists should be reminded of lymphoma as a differential diagnosis of spindle cell tumors.

A spindle cell variant of diffuse large B-cell lymphoma possesses genotypic and phenotypic markers characteristic of a germinal center B-cell origin

Lymphoma with prominent spindle cell features, the so-called spindle cell lymphoma, is an unusual morphological variant of diffuse large B-cell lymphoma. Five new cases of spindle cell lymphoma have been analyzed by a multiparameter approach in order to clarify its clinical and biological features. All patients presented advanced stage disease with extranodal involvement. Vagina was the most common extranodal site. All patients received chemotherapy and are alive in complete remission. Morphologically, all five cases exhibited proliferation of spindle cells with a vaguely storiform pattern highly suggestive of spindle cell neoplasms of nonlymphoid origin. In contrast, the results of immunohistochemical analysis indicated that all five cases were hematolymphoid neoplasms of the B-cell lineage. These lymphomas consisted of a B-cell clonal population which exhibited somatic immunoglobulin and BCL-6 mutations as well as BCL-6 protein expression. The neoplastic spindle cells therefore closely resemble B cells residing in the germinal center. The absence of MUM1 expression in neoplastic spindle cells suggested that neoplastic spindle cells may be related to the early phases of intragerminal center maturation of B cells. The germinal center phenotype, with restricted expression of BCL-6, was associated with the presence of a primary extranodal origin, normal lactate dehydrogenase levels, and good response to treatment.

Afectación cutánea específica en pacientes con mieloma múltiple. Estudio clínico-patológico, inmunohistoquímico y citogenético de 40 casos

INTRODUCTION

Specific cutaneous involvement in patients with multiple myeloma is very rare. When it does occur, it is in patients with advanced stages of multiple myeloma and with a large tumorous mass. In this study, we analyzed 40 patients with specific cutaneous involvement from multiple myeloma, with no bony lesions underlying the skin lesions, and we reviewed the related literature.

OBJECTIVES

We were particularly interested in the clinical course of these patients, including survival once skin metastases had developed and the possible influence of the different treatments administered.

MATERIAL AND METHODS

The study was completed by determining the histopathological pattern, the immunohistochemical profile, the type of immunoglobulin and immunoglobulin light chain produced by the neoplastic plasma cells that infiltrated the skin, as well as the cytogenetic characteristics of these cells.

RESULTS

From a clinical standpoint, the skin lesions consisted of multiple nodules or plaques with erythematous or violaceous coloration, and variable location. Histopathologically, two patterns were seen: nodular and diffuse interstitial. The plasma cells showed cytological atypia, and in one case they displayed a spindle shape, giving the lesion a sarcomatoid appearance. Immunohistochemically, these neoplastic plasma cells were strongly positive for CD79a, CD138, and EMA, while the immunoexpression of CD38 and CD43 was less intense and constant. In 39 of the 40 patients, the type of monoclonal immunoglobulin produced by the neoplastic plasma cells in the skin lesions was determined: 18 patients had IgA myeloma (5 IgAkappa and 13 IgAlambda), 19 patients had IgG myeloma (15 IgGkappa and 4 IgGlambda) and 2 patients had IgDlambda myeloma. The 22 cases in which immunoglobulin heavy chain gene rearrangement studies by PCR were carried out for the JH gene showed monoclonal rearrangement, while viral studies to try to identify genetic material of the HHV-8 virus and the Epstein-Barr virus gave negative results in all cases. These 22 cases studied using FISH showed the deletion of the rb-1 retinoblastoma gene in the neoplastic plasma cells that infiltrated the dermis. Despite aggressive chemotherapy, all of the patients died a few months after the skin lesions developed.

CONCLUSIONS

In our series, a perfect correlation was seen between the findings of serum electrophoresis and the immunohistochemistry of the skin lesions with regard to the type of immunoglobulin and the immunoglobulin light chain restriction produced by the neoplastic plasma cells. Patients with multiple myeloma have a very short survival period once specific skin lesions appear, regardless of the therapy administered. The deletion of the rb 1 gene may be a prognosis marker to identify those patients with especially aggressive forms of multiple myeloma.

Sarcomatoid variant of B-cell lymphoma of the uterine cervix

Malignant lymphomas with a prominent spindle-cell or sarcomatoid pattern are unusual tumors typically of T- or null-cell phenotypes. We encountered a case of a 32-year-old woman who presented with a 3-week history of excessive menstrual bleeding, left lower-quadrant pain, and weight loss. A mass involving the uterine cervix and right parametrium was detected on pelvic examination and imaging studies. A diagnosis of diffuse large B-cell lymphoma with a spindle-cell pattern was made with immunohistochemical and gene rearrangement studies on endocervical curettage and parametrial core biopsy specimens. After chemotherapy and radiation therapy, the patient was in clinical and radiological remission 10 months after diagnosis. To our knowledge, this is the first sarcomatoid B-cell lymphoma presenting in the uterine cervix. Awareness of the spindle-cell pattern of diffuse large B-cell lymphoma and its possible presentation in extranodal sites such as the uterine cervix should prevent potential misdiagnosis.