SPARC-positive macrophages are the superior prognostic factor in the microenvironment of diffuse large B-cell lymphoma and independent of MYC rearrangement and double-/triple-hit status.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with respect to outcome. Features of the tumor microenvironment (TME) are associated with prognosis when assessed by gene expression profiling. However, it is uncertain whether assessment of the microenvironment can add prognostic information to the most relevant and clinically well-established molecular subgroups when analyzed by immunohistochemistry (IHC). PATIENTS AND METHODS: We carried out a histopathologic analysis of biomarkers related to TME in a very large cohort (n = 455) of DLBCL treated in prospective trials and correlated with clinicopathologic and molecular data, including chromosomal rearrangements and gene expression profiles for cell-of-origin and TME. RESULTS: The content of PD1+, FoxP3+ and CD8+, as well as vessel density, was not associated with outcome. However, we found a low content of CD68+ macrophages to be associated with inferior progression-free survival (PFS) and overall survival (OS; P = 0.023 and 0.040, respectively) at both univariable and multivariable analyses, adjusted for the factors of the International Prognostic Index (IPI), MYC break and BCL2/MYC and BCL6/MYC double-hit status. The subgroup of PDL1+ macrophages was not associated with survival. Instead, secreted protein acidic and cysteine rich (SPARC)-positive macrophages were identified as the subtype of macrophages most associated with survival. SPARC-positive macrophages and stromal cells directly correlated with favorable PFS and OS (both, P[log rank] <0.001, P[trend] < 0.001). The association of SPARC with prognosis was independent of the factors of the IPI, MYC double-/triple-hit status, Bcl2/c-myc double expression, cell-of-origin subtype and a recently published gene expression signature [lymphoma-associated macrophage interaction signature (LAMIS)]. CONCLUSIONS: SPARC expression in the TME detected by a single IHC staining with fair-to-good interobserver reproducibility is a powerful prognostic parameter. Thus SPARC expression is a strong candidate for risk assessment in DLBCL in daily practice.

Extramedullary hematopoiesis: a new feature of inherited thrombocytopenias?

Essentials Extramedullary hematopoiesis (EMH) represents a pathologic finding in adult life. We report a mass-like EMH in the presacral space in a patient with ANKRD26-related thrombocytopenia. We found possible correlation between EMH and conditions causing lifelong thrombocytopenia. EMH can cause masses of unknown origin in patients with inherited thrombocytopenias. SUMMARY: Most commonly located in the liver and spleen, extramedullary hematopoiesis (EMH) is the presence of hematopoietic tissue outside the bone marrow. MYH9-related thrombocytopenia (MYH9-RD) and ANKRD26-related thrombocytopenia (ANKRD26-RT) are two of the most frequent forms of inherited thrombocytopenia (IT). Until recently, EMH has been associated with neoplastic and non-neoplastic hematologic conditions in which ITs were not included. We describe a case of mass-like EMH in the presacral space in a patient affected with ANKRD26-RT, comparing it with another case of paravertebral EMH we recently described in a subject with MYH9-RD. The surprisingly similitude of such a finding in the context of a group of rare disorders induces us to speculate about the possible pathogenic relationship between EMH and conditions causing lifelong thrombocytopenia, particularly the entity of ITs. Finally, we suggest that EMH has to be taken into consideration in the diagnostic work-up of masses of unknown origin in subjects affected with ITs.

Chronic localized leukocytoclastic vasculitis: clinicopathological spectrum of granuloma faciale with and without extrafacial and mucosal involvement.

Granuloma faciale (GF) is a rare cutaneous condition of unknown origin, that usually presents as one or more brown-purple papules, plaques and/or nodules, localized mostly on the face, although extrafacial lesions can also occur. Eosinophilic angiocentric fibrosis (EAF) is regarded as the mucosal counterpart of GF. Histologically, it has been described as a persistent leukocytoclastic vasculitis, with a dense polymorphous inflammatory infiltrate in the superficial and mid dermis, typically sparing the subpapillary dermis, the so called grenz zone. The presence of eosinophils is considered a characteristic feature of the disease. All the cases of GF seen at the Dermatology Unit from 2002 to 2013 were considered and reviewed, both clinically and histopathologically. Only cases with consistent clinical findings of GF, and accurate patient's history were considered. Ten cases of GF were reviewed for both histological specificity and clinico-pathological correlation. Two patients presented extrafacial lesions. One patient had involvement of nasal mucosa. Two patients suffered from associated rheumatological diseases. The most frequent histopathologic features were the presence of a grenz zone and eosinophils in the infiltrate, but also adnexal involvement was often present; vascular changes were constant, yet leukocytoclastic vasculitis could be recorded only in four cases. Fibrosis or sclerosis were always absent. Clinical pictures of the patients treated demonstrated a complete remission of the lesions, without scarring. However, a complete enduring healing was observed only in two patients, and relapse or incomplete remission of the disease was the rule. In conclusion a review of clinicopathological findings of ten patients affected by GF was made and new details of the disease presented.

Primary cutaneous diffuse large B-cell lymphoma (PCDLBCL), leg-type and other: an update on morphology and treatment.

Primary cutaneous B-cell lymphoma (PCBCL) is an heterogeneous group of lymphoproliferative disorders, which account for 25-30% of all primary cutaneous lymphoma and include three main histotypes: 1) primary cutaneous marginal zone B-cell lymphoma (PCMZL); 2) primary cutaneous follicular center cell lymphoma (PCFCL); 3) primary cutaneous diffuse large B-cell lymphoma (DLBCL), leg type (PCDLBCL-LT). PCMZL and PCFCL are indolent lymphomas, with an excellent prognosis despite an high rate of cutaneous recurrences; in contrast, PCDLBCL-LT is clinically more aggressive and usually requires to be treated with multi-agent chemotherapy and anti-CD20 monoclonal antibodies. PCDLBCL-LT histologically consists of large round cells (centroblasts and immunoblasts), is characterized by strong bcl-2 expression, in the absence of t(14;18) translocation, and resembles the activated B-cell type of nodal DLBCL. Recently, the term primary cutaneous DLBCL-other (PCDLBCL-O) has been proposed to include diffuse lymphomas composed of large transformed B-cells that lack the typical features of PCDLBCL-LT and do not conform to the definition of PCFCL. Some clinical studies suggested that such cases have an indolent clinical course and may be treated in a conservative manner; however, data regarding the actual prognosis and clinical behaviour of these peculiar cases are still too limited. The spectrum of primary cutaneous DLBCL also encompasses some rare morphological variants, such as anaplastic or plasmablastic subtypes and T-cell rich B-cell lymphoma, and some recently described, exceedingly rare DLBCL subtypes, such as intravascular large B-cell lymphoma and EBV-associated large B-cell lymphoma of the elderly, which often present in the skin.