The Histomorphologic Spectrum of Primary Cutaneous Diffuse Large B-Cell Lymphoma: A Study of 79 Cases

Lymphomas of the Vulva: A Review of the MITO Rare Cancer Group

Since they are very rare tumors, lymphomas of the vulva are often not properly recognized. Patients with vulvar lymphoma are generally elderly and the classical manifestation of the disease is a vulvar mass. No significant age differences have been found between primary and secondary lymphoma. To make a correct diagnosis, it is therefore necessary to use not only histological examination but also the genetic and molecular profile in order to establish optimal therapeutic management. Literature analysis confirm the good prognosis of this disease.

Primary diffuse large B-cell lymphoma of the vulva: a case report

Diffuse large B-cell lymphoma (DLBCL) is a subtype of non-Hodgkin lymphoma (NHL) and is estimated to account for approximately 30% of all NHL cases. NHL can also occur in the female genital tract and accounts for approximately 1.5% of all NHL cases. Many doctors have difficulty diagnosing or treating vulvar DLBCL because of its very low prevalence. A 55-year-old woman presented with a solid mass on the right side of the vulva. No significantly enlarged lymph nodes were observed in the inguinal region. She underwent excisional biopsy at our institution. DLBCL was diagnosed based on histological examination. According to the Hans algorithm, the lesion was diagnosed as a non-germinal center B-cell-like subtype. The patient was referred to a hematologic oncologist. The disease stage was classified as IE according to the Ann Arbor staging classification. The patient received four cycles of chemotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone and localized radiation therapy with 36 Gy in 20 fractions. She showed complete remission and maintained this status on the latest computed tomography scan. Gynecologists should rule out lymphoma in patients presenting with a vulvar mass.

Aggressive Cutaneous Lymphomas and Their Mimics

Cutaneous lymphomas encompass a heterogeneous group of neoplasms with a wide spectrum of clinical presentations, histopathologic features, and prognosis. Because there are overlapping pathologic features among indolent and aggressive forms and with systemic lymphomas that involve the skin, clinicopathologic correlation is essential. Herein, the clinical and histopathologic features of aggressive cutaneous B- and T-cell lymphomas are reviewed. Indolent cutaneous lymphomas/lymphoproliferative disorders, systemic lymphomas, and reactive processes that may mimic these entities are also discussed. This article highlights distinctive clinical and histopathologic features, increases awareness of rare entities, and presents new and evolving developments in the field.

Morphologic Patterns and the Correlation With MYD88 L265P, CD79B Mutations in Primary Adrenal Diffuse Large B-Cell Lymphoma

Primary adrenal diffuse large B-cell lymphoma (PA-DLBCL) is a rare subtype of extranodal DLBCL. Because of the rarity of this disease, its morphologic and genetic features are not comprehensively studied. Here, we systematically reviewed the clinicopathologic features of 42 cases of PA-DLBCL from our institution and investigated the frequency of MYD88 L265P and CD79B (exon 5) mutation in 29 eligible cases using Sanger sequencing. Clinically, PA-DLBCL was predominant in elderly male patients with advanced clinical stage and poor outcomes. Morphologically, the tumors often showed a sinusoidal and/or cohesive pattern with condensed chromatin and inconspicuous nucleolus which mimicked neuroendocrine carcinoma. Moreover, increased Reed-Sternberg-like cells were observed frequently. These confounding morphologic manifestations may lead to misdiagnosis. Genetically, PA-DLBCL harbored a high prevalence of MYD88 L265P (24%) and CD79B mutations (52%) which may be involved in lymphomagenesis. The CD79B mutation was significantly associated with a worse prognosis. A novel Histo-Molecular Classification system (4 categories) was proposed based on correlation with genetic changes. Generally, the neuroendocrine carcinoma-like type was associated with CD79B mutation, whereas the RS-like cell type indicated MYD88 L265P. The biphasic type was correlated with coexisting mutations of MYD88 and CD79B, whereas the common type implied no mutation. Furthermore, the common type showed significantly better survival. In conclusion, the proposed new category system could indicate the genetic changes as well as facilitate risk stratification to guide treatment and predict prognosis. Although this study augmented our understanding of PA-DLBCL, further analysis is required to validate our results and extend them to extranodal DLBCL at other sites.

Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type: A Case Report

Primary cutaneous diffuse large B-cell lymphoma, leg type, is an exceedingly rare and aggressive variant of primary cutaneous lymphoma. An 84-year-old male presented to an oncologist for new skin lesions on his abdomen and right thigh. Excisional biopsy followed by histopathology and immunohistochemistry confirmed the diagnosis of primary cutaneous diffuse large B-cell lymphoma, leg type. His clinical course was complicated by multiple relapses and refractory disease. Ultimately, he achieved complete response with fourth-line ibrutinib therapy. Due to the contentious nature of this disease, poor prognosis, and higher rates of recurrence, prompt identification and aggressive treatment are recommended. Given the different cellular pathways and genomic alterations identified in its carcinogenesis, various chemotherapy regimens and targeted immunotherapies have emerged as potential therapeutic options to halt disease progression and prevent future relapses.

Primary cutaneous diffuse large B-cell lymphoma, NOS and leg type: Clinical, morphologic and prognostic differences

BACKGROUND AND OBJECTIVES

Primary cutaneous diffuse large B-cell lymphoma, NOS (PCLBCL/NOS) is a rare PCLBCL. Only few data are available for this tumor. The aim of this study was to identify clinical and/or immunohistochemical markers (in addition to Bcl-2) that characterize PCLBCL/NOS, assist in differentiating it from PCLBCL, leg type (PCLBCL/LT) and help to assess the clinical course/prognosis.

PATIENTS AND METHODS

Bcl-2^- PCLBCL/NOS) cases (n = 14 were compared with Bcl-2⁺ PCLBCL/LT cases (n = 29).

RESULTS

PCLBCL/NOS patients were younger, predominantly male and had better survival rates than patients with PCLBCL/LT. Patients with PCLBCL/NOS presented more often with larger plaques limited to one or two contiguous body regions, whereas PCLBCL/LT cases often presented with disseminated lesions. Neoplastic cells had a higher proliferation rate (Ki67) in PCLBCL/LT patients. The tumor microenvironment of PCLBCL/NOS had a more prominent CD3⁺ infiltrate. Overall survival data for the whole cohort (n = 37) revealed that female gender and Bcl-2 expression correlated with a worse survival rate. Bcl-6 expression and centroblastic subtype correlated with better outcomes. None of the other markers studied (e.g. GCB/non-GCB subtype) correlated with survival rate.

CONCLUSIONS

PCLBCL/NOS and PCLBCL/LT differ in their clinical behavior and outcomes. Bcl-2 still seems to be the best marker for discriminating between these two subgroups. Bcl-2, female gender and Bcl-6 represent prognostic markers for PCLBCL.

Double-hit or dual expression of MYC and BCL2 in primary cutaneous large B-cell lymphomas

In nodal diffuse large B-cell lymphoma, the search for double-hit with MYC and BCL2 and/or BCL6 rearrangements or for dual expression of BCL2 and MYC defines subgroups of patients with altered prognosis that has not been evaluated in primary cutaneous large B-cell lymphoma. Our objectives were to assess the double-hit and dual expressor status in a cohort of 44 patients with primary cutaneous large B-cell lymphoma according to the histological subtype and to evaluate their prognosis relevance. The 44 cases defined by the presence of more than 80% of large B-cells in the dermis corresponded to 21 primary cutaneous follicle centre lymphoma with large cell morphology and 23 primary cutaneous diffuse large B-cell lymphoma, leg type. Thirty-one cases (70%) expressed BCL2 and 29 (66%) expressed MYC. Dual expressor profile was observed in 25 cases (57%) of either subtypes (n = 6 or n = 19, respectively). Only one primary cutaneous follicle centre lymphoma, large-cell case had a double-hit status (2%). Specific survival was significantly worse in primary cutaneous diffuse large B-cell lymphoma, leg type than in primary cutaneous follicle centre lymphoma, large cell (p = 0.021) and for the dual expressor primary cutaneous large B-cell lymphoma group (p = 0.030). Both overall survival and specific survival were worse for patients belonging to the dual expressor primary cutaneous diffuse large B-cell lymphoma, leg type subgroup (p = 0.001 and p = 0.046, respectively). Expression of either MYC and/or BCL2 negatively impacted overall survival (p = 0.017 and p = 0.018 respectively). As the differential diagnosis between primary cutaneous follicle centre lymphoma, large cell and primary cutaneous diffuse large B-cell lymphoma, leg type has a major impact on prognosis, dual-expression of BCL2 and MYC may represent a new diagnostic criterion for primary cutaneous diffuse large B-cell lymphoma, leg type subtype and further identifies patients with impaired survival. Finally, the double-hit assessment does not appear clinically relevant in primary cutaneous large B-cell lymphoma.

Multiple Subcutaneous Nodules as Initial Presentation of Diffuse Large B-cell Non-Hodgkin Lymphoma (DLBCL) Detected by PET/CT

Subcutaneous tissue as a manifestation of generalized disease is commonly involved in lymphomas. However, only skin involvement without other sites of extracutaneous disease was rarely presented, especially in diffuse large B-cell lymphoma (DLBCL). Herein, we reported an unusual case of primary cutaneous DLBCL, solely presenting with multiple subcutaneous nodules in the abdomen and back, and these nodules showed increased FDG uptake on PET/CT images. PET/CT is very helpful for diagnosing primary cutaneous DLBCL.

Primary Cutaneous B-cell Lymphomas

B-cell lymphomas represent approximately 20% to 25% of primary cutaneous lymphomas. Within this group, most cases (>99%) are encompassed by 3 diagnostic entities: primary cutaneous marginal zone lymphoma, primary cutaneous follicle center lymphoma, and primary cutaneous diffuse large B-cell lymphoma, leg type. In this article, the authors present clinical, histopathologic, immunophenotypic, and molecular features of each of these entities and briefly discuss the rarer intravascular large B-cell lymphoma.

Cytologic perspectives on neoteric B-cell lymphoproliferative disorders

The 2008 World Health Organization (WHO) classification of hematopoietic and lymphoid tissues has been recently revised, and publication of the updated 2016 version is expected soon. Given that cytopathologists are often involved in the diagnosis of primary, recurrent, and transformed lymphoproliferative disorders, knowledge of updates to the WHO lymphoma classification, including terminology, pathogenesis, ancillary techniques, and targeted therapies is necessary. Herein, we reference the last decade of cytology specific literature for seven newer B-cell disorders and provide illustrative examples of each entity from our files.

Epidermotropic B-Cell Lymphoma: A Unique Subset of CXCR3-Positive Marginal Zone Lymphoma

BACKGROUND

Epidermotropic B-cell lymphoma is a very rare entity that has primarily been reported in the literature as anecdotal case reports. The majority of the reported cases exhibit a diffuse skin rash affecting middle-aged to older adults with a male predominance. The exact mechanism of marginal zone B-cell localization to the epidermis is unclear.

MATERIAL AND METHODS

To describe a very rare subset of cutaneous B-cell lymphoma and explore potential pathogenetic mechanisms for the epidermotropic tendency, the hospital database and literature review was conducted to isolate cases of epidermotropic B-cell lymphoma. Routine hematoxylin and eosin stain followed by selective phenotypic studies.

RESULTS

Two of the cases were encountered in the hospital database, whereas 5 cases have been previously reported; material was requested on previously reported cases and was received on 3 of them. In one of the 2 cases encountered in our database, the patient presented with a progressive skin rash over 7 months resembling pityriasis rosea. Subsequent to a diagnosis of B-cell lymphoma, further staging revealed bone marrow involvement. The other patient, an elderly female, presented with isolated nodules. The biopsies of both cases showed areas of superficial band-like lymphocytic infiltration with large monocytoid appearance and an epidermotropic pattern of lymphocyte migration into the epidermis. Neoplastic cells were extensively positive for CD20, CD79a, and BCL-2 and negative for CD10 and BCL-6. Of interest, a similar pityriasis rosea-like presentation was encountered in the cases reported in the literature. All patients were elderly males with established bone marrow, peripheral blood, and spleen involvement several months to years after the initial cutaneous presentation in 3 of them. None of the patients to date have died of lymphoma. CXCR3 epidermotropic B cells were detected in both our cases and in 3 of the 3 previously published cases.

CONCLUSIONS

Epidermotropic B-cell lymphoma represents a subset of marginal zone lymphoma characterized by a papulosquamous rash most frequently resembling pityriasis rosea, occurring almost exclusively in older males. We speculate that aberrant expression of CXCR3 in marginal zone lymphoma of the skin is associated with migration of lymphoma cells to the epidermis and could lead to an epidermotropic pattern given the known role of CXCR3 expression in neoplastic T cells in the localization of mycosis fungoides to the epidermis. There is a tendency toward bone marrow, spleen, and peripheral blood involvement.

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.

Cutaneous lymphomas: an update. Part 2: B-cell lymphomas and related conditions

: Primary cutaneous B-cell lymphomas (PCBCL) are the second most common form of primary cutaneous lymphomas and account for approximately 25%-30% of all primary cutaneous lymphomas. Both forms of low-grade malignant PCBCL, primary cutaneous follicle center lymphoma (PCFCL) and primary cutaneous marginal zone lymphoma of mucosa-associated lymphoid tissue-type (MALT lymphoma) (PCMZL) represent the vast majority of PCBCL and show an indolent slowly progressive course and an excellent prognosis despite a high recurrence rate. Genetic analysis indicates that PCMZL differ from other forms of extranodal MALT lymphomas. The more common class-switched and the non-class-switched form of PCMZL can be distinguished as two distinctive subsets that differ in the cellular composition, IgM expression, and biological behavior with extracutaneous involvement found in the non-class-switched form. Recently, unusual clinical and histological forms of PCMZL and PCFCL manifesting with miliary or agminated lesions have been described that are diagnostically challenging. In contrast to PCMZL and PCFCL, primary cutaneous diffuse large B-cell lymphoma, leg type, and other rare forms of large B-cell lymphomas such as intravascular large B-cell lymphoma have an unfavorable prognosis. There is an emerging group of Epstein-Barr virus (EBV)-driven B-cell lymphoproliferations including posttransplant lymphoproliferative disorders and mucocutaneous ulcer occurring in immunocompromised patients and EBV-associated diffuse large B-cell lymphoma of the elderly arising in the setting of senescence-linked immunodeficiency. This review reports on recent findings expanding the spectrum of clinicopathological features, differential diagnostic aspects, and the pathogenesis of PCBCL and discusses the group of EBV-associated B-cell lymphoproliferations involving the skin.

Primary Cutaneous B-Cell Lymphomas

B-cell lymphomas occurring in the skin often tend to be of systemic origin with secondary cutaneous involvement. Primary cutaneous B-cell lymphomas tend to be indolent disorders, with the exception of primary cutaneous diffuse large B-cell lymphoma-leg type (PCDLBCL-LT). In indolent conditions, the distinction between cutaneous lymphoma and cutaneous lymphoid hyperplasia can be difficult. Integration of all available information, including the clinical setting, is crucial to arriving at the appropriate diagnosis. In this review, we cover the diagnostic approaches to primary cutaneous marginal zone lymphoma, primary cutaneous follicle center lymphoma, and PCDLBCL-LT, and discuss their differential diagnosis.

Cutaneous B-cell lymphoproliferative disorders: report of the 2011 Society for Hematopathology/European Association for Haematopathology workshop

The diagnosis and classification of the cutaneous B-cell lymphomas can be quite a challenge, with a definitive diagnosis sometimes being elusive, even when an extensive workup has been performed. Distinction of benign from neoplastic disorders can be difficult, with some hyperplasias mimicking lymphomas and vice versa. There are only a limited number of skin-specific B-cell lymphomas, including primary cutaneous follicle center lymphoma and primary cutaneous diffuse large B-cell lymphoma, leg type. Cutaneous marginal zone lymphomas have distinctive features but are classified with the other mucosa-associated lymphoid tissue lymphomas. It is important, however, to also remember that many other B-cell lymphomas/ plasma cell neoplasms can primarily, or more often secondarily, involve the skin. Some may mimic one of the skin-specific lymphomas but have very different clinical implications. Iatrogenic and senescent immunodeficiency-associated lymphoproliferative disorders that are often Epstein-Barr virus (EBV) positive can also primarily involve the skin, including cases also known as EBV-positive mucocutaneous ulcer.