Subcutaneous, Blastic Natural Killer (NK), NK/T-cell, and Other Cytotoxic Lymphomas of the Skin: A Morphologic, Immunophenotypic, and Molecular Study of 50 Patients

Cutaneous γδ T-cell lymphomas: a spectrum of presentations with overlap with other cytotoxic lymphomas

We reviewed our multicenter experience with gamma-delta (γδ) T-cell lymphomas first presenting in the skin. Fifty-three subjects with a median age of 61 years (range, 25 to 91 y) were diagnosed with this disorder. The median duration of the skin lesions at presentation was 1.25 years (range, 1 mo to 20 y). The most common presentation was deep plaques (38 cases) often resembling a panniculitis, followed by patches resembling psoriasis or mycosis fungoides (10 cases). These lesions tended to ulcerate overtime (27 cases). Single lesions or localized areas of involvement resembling cellulitis or pyoderma were reported in 8 cases. The most common anatomic site of involvement was the legs (40 cases), followed by the torso (30 cases) and arms (28 cases). Constitutional symptoms were reported in 54% (25/46) of the patients, including some with limited skin involvement. Significant comorbidities included autoimmunity (12 cases), other lymphoproliferative disorders (5 cases), internal carcinomas (4 cases), and viral hepatitis (2 cases). Lymphadenopathy (3/42 cases) and bone marrow involvement (5/28 cases) were uncommon, but serum lactose dehydrogenase (LDH) was elevated in 55% (22/39) of the patients. Abnormal positron emission tomography and/or computed tomography scans in 20/37 subjects mostly highlighted soft tissue or lymph nodes. Disease progression was associated with extensive ulcerated lesions resulting in 27 deaths including complications of hemophagocytic syndrome (4) and cerebral nervous system involvement (3). Median survival time from diagnosis was 31 months. Skin biopsies varied from a pagetoid pattern to purely dermal or panniculitic infiltrates composed of intermediate-sized lymphocytes with tissue evidence of cytotoxicity. The most common immunophenotype was CD3+/CD4⁻/CD5⁻/CD8⁻/BF1⁻/γ-M1+/TIA-1+/granzyme-B+/CD45RA-/CD7-, and 4 cases were Epstein-Barr virus positive. This is the largest study to date of cutaneous γδ T-cell lymphomas and demonstrates a variety of clinical and pathologic presentations with a predictable poor outcome.

Usefulness of F-18 FDG PET/CT in subcutaneous panniculitis-like T cell lymphoma: disease extent and treatment response evaluation

BACKGROUND.: Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare form of cutaneous lymphomas, accounting for less than 1% of cases of non-Hodgkin's lymphoma. Fluorine-18 fluorodeoxyglucose (F-18 FDG) positron-emission tomography/computed tomography (PET/CT) findings of SPTCL before and after treatment were rarely reported. CASE REPORT.: We report a case of SPTCL in which F-18 FDG PET/CT showed increased FDG accumulations in numerous subcutaneous nodules without extracutaneous disease. Contrast-enhanced CT during F-18 FDG PET/CT showed multiple minimally enhancing nodules with an infiltrative pattern in the subcutaneous layer throughout the body. Follow-up F-18 FDG PET/CT after three cycles of CHOP chemotherapy showed a complete metabolic remission of the lesions. CONCLUSIONS.: F-18 FDG PET/CT is suggested to be useful in assessing the disease activity, extent and treatment response in SPTCL.

The extent of cutaneous lesions predicts outcome in extranodal nasal-type natural killer/T-cell lymphoma of the upper aerodigestive tract with secondary cutaneous involvement

This study determined the clinical characteristics and prognosis for patients with extranodal nasal-type natural killer/T-cell lymphoma (NKTCL) with secondary cutaneous involvement. Twenty-eight patients with NKTCL of the upper aerodigestive tract with secondary cutaneous involvement were reviewed. The median overall survival (OS) was 21.5 months from the first diagnosis, and 12.3 months from the presentation of a cutaneous lesion. The 5-year OS rate was 43.1% (median, 28 months) for patients with localized cutaneous disease compared with 0% (median, 3.6 months) for generalized cutaneous disease (p = 0.017). The 2-year OS rates were 67.5% for patients who achieved a complete response (CR) compared with 19.4% (median, 5.2 months) for patients who did not (p = 0.003). Patients with NKTCL with secondary cutaneous dissemination overall have a poor prognosis, but a relatively favorable prognosis was identified for the small subgroup of patients who had localized cutaneous lesions and achieved a CR.

Comments on cutaneous lymphomas: since the WHO-2008 classification to present

The last classification of lymphomas of the World Health Organization in 2008 made a few changes from the preceding classification. Although useful, at the same time, it has posed new questions, concerns, and dilemmas which have been raised in the literature. The current report highlights some of these controversies, of each of these primary cutaneous entities, going through cutaneous mature T-cell and NK-cell neoplasms, mature B-cell neoplasms, precursor neoplasms, and other entities, which for several reasons do not fit in the previous categories. It also reviews some advances on many of these lymphomas published in the last 2 years.

Immunophenotype of skin lymphocytic infiltrate in patients co-infected with Mycobacterium leprae and human immunodeficiency virus: a scenario dependent on CD8+ and/or CD20+ cells

BACKGROUND

Leprosy occurs rarely in human immunodeficiency virus (HIV)-positive patients. In contrast to tuberculosis, there has been no report to date of an increase in HIV prevalence among patients with leprosy or of differences in leprosy's clinical spectrum. While several studies describe the systemic immune response profile in patients co-infected with HIV and leprosy, the local immune skin response has been evaluated in only a small number of case reports and limited series of patients.

OBJECTIVE

To investigate the interaction between Mycobacterium leprae and HIV infection in the skin.

METHODS

We investigated the presence and frequency of cells positive for CD4, CD8, CD20, TIA-1, FOXP3 and CD123 in lymphocytic infiltrates from 16 skin biopsies taken from 15 patients with HIV-leprosy co-infection.

RESULTS

CD4+ cells were absent in infiltrates from 6 (38%) skin biopsies and present in 10 (62%) cases at low levels (<1·16%) of the lymphocytic infiltrate. CD8+ was the predominant phenotype in the infiltrate (99·4%), followed by TIA-1, expressed by >75% of CD8+ cells. FOXP3+ cells were also present, representing 3·4% of the lymphocytic infiltrate. CD20+ cells were detected in 75% of the cases; however, in two cases (12%) these cells represented 25-50% of the infiltrate, while in the other 10 cases (62%) they were present only focally (<25% of the infiltrate). CD123+ cells were not observed in any of the studied specimens.

CONCLUSIONS

Data presented here suggest that cell-mediated immune responses to M. leprae are preserved at the site of disease and that in the absence of CD4+ cells, CD8+FOXP3+ and CD20+ cells may be involved in granuloma formation.

Subcutaneous panniculitis-like T-cell lymphoma: a clinical and pathologic study of 14 korean patients

Background

Subcutaneous panniculitis-like T-cell lymphoma (SPTL) is a distinctive skin lymphoma characterized by neoplastic T-cell infiltration of the subcutaneous tissue, mimicking panniculitis.

Objective

To describe the clinical and pathologic features of SPTL in Korean patients.

Methods

Fourteen SPTL patients evaluated over 15 years were retrospectively reviewed.

Results

The mean patient age was 35 years (range: 7~73 years), with male predominance (2.5:1). Most patients presented with either nodules or plaques, occurring most commonly on the trunk, with two patients (14%) having hemophagocytic syndrome. Histopathologically, all patients showed infiltrates of small-to-medium pleomorphic cells mimicking panniculitis, with some also showing rimming, bean-bag cells, and fat necrosis. Most patients were positive for CD3 (14/14), CD8 (12/13), TIA-1 (9/9) and βf1 (5/5), but were negative for CD4 (11/12), CD20 (8/8), CD56 (14/14) and Epstein-Barr virus (8/8). Ten patients (71%) received chemotherapy and 2 (14%) died due to the disease, with an average survival time of 4 months. Survival analysis did not reveal any significant prognostic factors.

Conclusion

This is the first series of patients with SPTL in Korea. Due to its indolent clinical course and relatively high survival rate, SPTL should be differentiated from cutaneous γδ T-cell lymphoma.

Primary cutaneous lymphomas: a reprisal

Primary cutaneous lymphomas (PCLs) are a group of lymphoid neoplasms provided with heterogeneous clinical, histological, immunohistochemical and molecular features. They can be classified in two groups: cutaneous T-cell lymphomas (CTCLs) and cutaneous B-cell lymphomas (CBCLs). Recent studies show an increase of the incidence of PCLs over the last three decades. Our aim is to evaluate the commonest types of PCL analysing the clinical characteristics, histology, phenotype, molecular biology, prognosis and therapy.

Guidelines for the management of mature T-cell and NK-cell neoplasms (excluding cutaneous T-cell lymphoma)

The peripheral T-cell neoplasms are a biologically and clinically heterogeneous group of rare disorders that result from clonal proliferation of mature post-thymic lymphocytes. Natural killer (NK) cell neoplasms are included in this group. The World Health Organization classification of haemopoietic malignancies has divided this group of disorders into those with predominantly leukaemic (disseminated), nodal, extra-nodal or cutaneous presentation. They usually affect adults and are more commonly reported in males than in females. The median age at diagnosis is 61 years with a range of 17-90 years. Although some subtypes may follow a relatively benign protracted course most have an aggressive clinical behaviour and poor prognosis. Excluding anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL), which has a good outcome, 5-year survival for other nodal and extranodal T-cell lymphomas is about 30%. Most patients present with unfavourable international prognostic index scores (>3) and poor performance status. The rarity of these diseases and the lack of randomized trials mean that there is no consensus about optimal therapy for T- and NK-cell neoplasms and recommendations in this guideline are therefore based on small case series, phase II trials and expert opinion.

An illustrative case of subcutaneous panniculitis-like T-cell lymphoma

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a very rare form of skin lymphoma that is localized primarily to the subcutaneous adipose tissue without palpable involvement of the lymph nodes. Diagnosis of SPTCL is a challenge, especially during its early phases when symptoms mimic other, more common conditions, such as benign panniculitis, eczema, dermatitis, psoriasis and cellulitis. Clinical and systemic features are nonspecific and can include fever, chills, and weight loss. Further complicating diagnosis is the high number of false negatives provided by biopsy. Here we present a case of SPTCL that illustrates the full course of the disease, from presentation and multiple misdiagnoses to correct disease recognition and successful treatment. A review of the challenges of diagnosis is provided with recommendations for more accurate and timely recognition of SPTCL.

Subcutaneous Panniculitis-Like T-Cell Lymphoma (SPTL) in a Child with Spontaneous Resolution

Subcutaneous panniculitis-like T-cell lymphomas (SPTLs) α/β are rare in childhood. The present report refers to a case of a 7-year-old male child presenting an extensive skin lesion that began when he was 5 years of age. Two biopsies were evaluated using the CD3, CD4, CD8, CD56, βF1, and TIA markers. A dense infiltrate of CD3+, CD4-, CD8+, CD56-, βF1+, and TIA+ pleomorphic lymphocytes was found in the subcutis. The previous biopsy showed cytophagic histiocytic panniculitis with a small focus on CD8+ and βF1+ malignant cells. The lesion regressed spontaneously. This case shows that prognosis may be excellent in SPTL (α/β). On the other hand, it also serves as an alert that a biopsy performed in an area of cytophagic panniculitis may lead to misdiagnosis.

Subcutaneous panniculitis-like T-cell lymphoma with breast involvement: functional and morphological imaging findings

Panniculitis-like T-cell lymphoma is a very uncommon subtype of cutaneous T-cell lymphomas. In this case report, we describe the morphological (CT and MRI) and functional ((18)F-FDG-PET and bone scan) imaging findings in a 35-year-old patient who suffered from slowly progressing multiple subcutaneous lesions caused by this rare disease.

A case with an indolent course of subcutaneous panniculitis-like T-cell lymphoma demonstrating Epstein-Barr virus positivity and simulating dermatitis artefacta

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare form of cytotoxic T-cell lymphoma. The disease has a poor prognosis in patients with the complication of hemophagocytic syndrome, especially in those with Epstein-Barr virus (EBV) positivity. A 20-year-old woman presented with multiple, itchy, purplish nodules and excoriations on both of her upper limbs. The histopathologic, immunohistochemical staining, and clonal T-cell receptor gene rearrangement examinations of skin lesions revealed the diagnosis of SPTCL. In situ hybridization performed for EBV was positive. There were no findings suggesting systemic involvement of SPTCL, or hemophagocytic syndrome. The lesions improved with systemic corticosteroid therapy and radiotherapy, with no recurrence. We present a patient with a protracted course of SPTCL in whom EBV positivity was demonstrated. This apparent conflict may be explained by geographic and ethnic variations in EBV infection. Further studies may shed light on the real relationship between EBV-RNA and the course of SPTCL.

Immunohistochemistry in the diagnosis of cutaneous neoplasms

In recent years, there has been a significant increase in the number of diagnostic immunohistochemical stains available to pathologists and dermatopathologists. Immunohistochemistry has become an indispensable tool in dermatopathology, not only in diagnosis but also in the treatment and prognostication of cutaneous neoplasms. In this review we attempt to outline current, as well as new, immunohistochemical stains of relevance in the diagnosis and classification of cutaneous neoplasms.

Gamma-delta T-cell lymphomas

Peripheral T-cell lymphomas (TCLs) are uncommon neoplasms, accounting for about 12% of all lymphoid tumors worldwide. TCLs in which gammadelta T-cell receptors are expressed (gammadelta TCLs) are extremely aggressive and rare (<1% of lymphoid neoplasms). gammadelta TCLs originate from gammadelta T cells, a small subset of peripheral T cells with direct antigen recognition capability acting at the interface between innate and adaptive immunity. Two distinct gammadelta TCL entities are recognized: hepatosplenic T-cell lymphoma (HSTL) and primary cutaneous gammadelta T-cell lymphoma (PCGD-TCL). HSTL is a well-characterized extranodal lymphoma that has a disguised onset, secondary to intrasinusoidal infiltration of the spleen, liver and bone marrow, has a rapidly progressive course that is poorly responsive to chemotherapy, and often ensues in the setting of immune system suppression. PCGD-TCL can present with prominent epidermal involvement or with a panniculitis-like clinical picture that can be complicated by a concurrent hemophagocytic syndrome; the disease shows biological and phenotypic overlap with other extranodal gammadelta TCLs that involve the respiratory or gastrointestinal tract mucosa. The regular application of phenotypic and molecular techniques is crucial for the diagnosis of gammadelta TCLs. In this Review, we discuss the clinical and biological features, the diagnostic challenges and the therapeutic perspectives of HSTL and PCGD-TCL.

Cyclosporin in subcutaneous panniculitis-like T-cell lymphoma

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare form of hematologic malignancy characterized by lesions in subcutaneous fat associated with systemic symptoms. The standard treatment of the disease, currently, is not established, but CHOP or CHOP-like regimens are usually given. We report, herein, 4 cases of SPTCL diagnosed by histopathology and immunohistochemistry who were refractory to CHOP and/or ESHAP and/or fludarabine-based regimen, but showed rapid improvement within weeks after oral cyclosporin 4 mg/kg/day. Three sustained complete remission for the durations of 8 - 9 months off-treatments. T-cell receptor gene rearrangement revealed polyclonality in 3 cases and monoclonality in 1 case. Our data suggest the benefit of incorporating cyclosporin into the treatment regimen for SPTCL.

Primary cutaneous T-cell lymphoma of unspecified type with cytotoxic phenotype: clinicopathological analysis of 27 patients

The objective of our study was to investigate the clinicopathological features of the currently ill-defined subtype of primary cutaneous T-cell lymphoma of unspecified type (CTCLU) with a cytotoxic phenotype and no Epstein-Barr virus (EBV) association. A series of 27 patients with CTCLU (median age 49 years; range 25-87 years; 18 men) was reviewed. Performance status scores above 1 (7%), clinical stages above 2 (15%), B symptoms (26%), extracutaneous involvement (30%), and a fatal course within 1 year of diagnosis (19%) were observed infrequently. The International Prognostic Index was high or high to intermediate in 11%, and the Prognostic Index for Peripheral T-cell Lymphoma unspecified was above group 2 in 22%. Notably, the rates of spontaneous regression and T-cell receptor gene rearrangements by polymerase chain reaction analysis were seen in 26 and 17% of our cases, respectively. Histologically, 22 patients had subcutaneous involvement of whom eight showed a lethal clinical course, and five patients without subcutaneous involvement were all survivors. Immunophenotypical and morphological features allowed us to subclassify our cases according to the following four categories: (1) epidermotropic CD8+ T-cell lymphoma (n=5); (2) cutaneous gamma/delta T-cell lymphoma (n=8); (3) cutaneous alpha/beta pleomorphic T-cell lymphoma (n=8); and (4) cutaneous medium/large pleomorphic T-cell lymphoma, not otherwise specified (n=6). All four of these groups of lymphomas exhibited a relatively favorable clinical course compared to previous reports. However, epidermotropic CD8+ T-cell lymphoma appeared to be unique with a higher ratio (80%) of spontaneous regression, a lower ratio (40%) of subcutaneous involvement, and a more favorable clinical course than the other three subcategories.

Clinicopathological characterization and genomic aberrations in subcutaneous panniculitis-like T-cell lymphoma

Subcutaneous panniculitis-like T-cell lymphomas (SPTLs) represent a rare, difficult-to-diagnose, and poorly characterized subtype of cutaneous T-cell lymphomas (CTCLs) affecting younger people more than the other CTCL forms. We performed a thorough clinical, immunohistological, and molecular analysis of nine Finnish SPTL patients. Specifically, we performed single-cell comparative genomic hybridization (CGH) from laser microdissected, morphologically malignant SPTL cells, as well as loss of heterozygosity (LOH) and fluorescence in situ hybridization (FISH) analysis for the NAV3 (neuron navigator 3) gene. CGH revealed large numbers of DNA copy number changes, the most common of which were losses of chromosomes 1pter, 2pter, 10qter, 11qter, 12qter, 16, 19, 20, and 22 and gains of chromosomes 2q and 4q. Some of the DNA copy number aberrations in SPTL, such as loss of 10q, 17p, and chromosome 19, overlap with those characteristic of common forms of CTCL (mycosis fungoides (MF) and Sezary syndrome (SS)), whereas 5q and 13q gains characterize SPTL. Allelic NAV3 aberrations (LOH or deletion by FISH), previously found in MF and SS, were identified in 44% of the SPTL samples. This study demonstrates that SPTL is also moleculocytogenetically a uniform entity of CTCL and supports the current World Health Organization-European Organization for Research and Treatment of Cancer (WHO-EORTC) classification defining SPTL as a subgroup of its own.

Is nonsmall cell type high-grade neuroendocrine carcinoma of the tubular gastrointestinal tract a distinct disease entity?

Although small cell carcinoma of the gastrointestinal (GI) tract is well-recognized, nonsmall cell type high-grade neuroendocrine carcinoma (HGNEC) of this site remains undefined. At the current time, neither the World Health Organization nor American Joint Committee on Cancer includes this condition in the histologic classifications, and consequently it is being diagnosed and treated inconsistently. In this study, we aimed at delineating the histologic and immunophenotypical spectrum of HGNECs of the GI tract with emphasis on histologic subtypes. Guided primarily by the World Health Organization/International Association for the Study of Lung Cancer criteria for pulmonary neuroendocrine tumors, we were able to classify 87 high-grade GI tract tumors that initially carried a diagnosis of either poorly differentiated carcinoma with or without any neuroendocrine characteristics, small cell carcinoma, or combined adenocarcinoma-neuroendocrine carcinoma into the following 4 categories. The first was small cell carcinoma (n=23), which had features typical of pulmonary small cell carcinoma, although the cells tended to have a more round nuclear contour. The second was large cell neuroendocrine carcinoma (n=31), which had a morphology similar to its pulmonary counterpart and showed positive immunoreactivity for either chromogranin (71%) or synaptophysin (94%) or both. The third was mixed neuroendocrine carcinoma (n=11), which had intermediate histologic features (eg, cells with an increased nuclear/cytoplasmic ratio but with apparent nucleoli), and positive immunoreactivity for at least 1 neuroendocrine marker. The fourth was poorly differentiated adenocarcinoma (n=17). In addition, 5 of the 87 tumors showed either nonsmall cell type neuroendocrine morphology (n=3) or immunohistochemical reactivity for neuroendocrine markers (n=2), but not both. Further analysis showed that most HGNECs arising in the squamous lined parts (esophagus and anal canal) were small cell type (78%), whereas most involving the glandular mucosa were large cell (53%) or mixed (82%) type; associated adenocarcinomas were more frequent in large cell (61%) or mixed (36%) type than in small cell type (26%); and focal intracytoplasmic mucin was seen only in large cell or mixed type. As a group, the 2-year disease-specific survival for patients with HGNEC was 25.4% (median follow-up time, 11.3 mo). No significant survival difference was observed among the different histologic subtypes. In conclusion, our study demonstrates the existence of both small cell and nonsmall cell types of HGNEC in the GI tract, and provides a detailed illustration of their morphologic spectrum. There are differences in certain pathologic features between small cell and nonsmall cell types, whereas the differences between the subtypes of nonsmall cell category (large cell versus mixed) are less distinct. Given the current uncertainty as to whether large cell neuroendocrine carcinoma is as chemosensitive as small cell carcinoma even in the lung, our data provide further evidence in favor of a dichotomous classification scheme (small cell vs. nonsmall cell) for HGNEC of the GI tract. Separation of nonsmall cell type into large cell and mixed subtypes may not be necessary. These tumors are clinically aggressive. Prospective studies using defined diagnostic criteria are needed to determine their biologic characteristics and optimal management.

The morphologic spectrum of primary cutaneous anaplastic large T-cell lymphoma: a histopathologic study on 66 biopsy specimens from 47 patients with report of rare variants

BACKGROUND

Primary cutaneous anaplastic large T-cell lymphoma (PCALCL) is a well-defined entity with prognostic differences from the nodal counterpart [nodal anaplastic large cell lymphoma (NALCL)]. Several histological variants of NALCL have been characterized (common, lymphohistiocytic and small cell). However, studies on morphological variants of PCALCLs are lacking.

METHODS

We analyzed retrospectively the clinicopathologic features of 66 biopsies from 47 patients (M : F = 27 : 20; median age: 53 years; mean age: 51.8 years; range: 14-82) with PCALCL, in order to better characterize the spectrum of this unusual neoplasm.

RESULTS

The 'common variant' was the most frequent (40.4%). In contrast to NALCL, in PCALCL, marked reactive infiltrates are more commonly present. In fact, 26 cases were classified as 'inflammatory type' (15 cases) and 'lymphohistiocytic' (11 cases). Concerning the predominant cell morphology, large anaplastic cells (33%) were almost as frequent as large pleomorphic (36%) and small to medium-sized cells (26%). We reported for the first time in the skin 2 rare cases with the predominance of large cells with a 'signet-ring'-like appearance. Epidermotropism and presence of eosinophils were found in a proportion of cases in all PCALCL variants.

CONCLUSIONS

PCALCL is characterized by variable histopathological presentations and a broad cytomorphologic spectrum.

CD4+/CD56+ hematodermic neoplasm: presentation of 2 cases and review of the concept of an uncommon tumor originated in plasmacytoid dendritic cells expressing CD123 (IL-3 receptor alpha)

CD4/CD56 hematodermic neoplasm is a rare neoplasm presenting with cutaneous nodules, lymphadenopathy, bone marrow infiltration, and an aggressive clinical course. Recently, the plasmacytoid dendritic cell origin of this neoplasm has been demonstrated. Plasmacytoid dendritic cell is a hematopoietic-derived cell implicated in the regulation of innate and adaptive cell immunity and in the production of certain regulatory cytokines. Recently it has been demonstrated that these cells express cell surface markers such as IL-3 receptor alpha (CD123). In the present report, we describe the clinical, histologic, and immunohistochemical characteristics of 2 cases of CD4/CD56 hematodermic neoplasm. Both patients were male and the age at the time of diagnosis was 36 and 75 years, respectively. Clinical findings were limited to the skin and consisted of multiple cutaneous nodules located in the thorax and extremities, some of them ulcerated. Histologically, the tumors were characterized by a nonepidermotropic, dermal and subdermal infiltration of homogeneous medium-sized cells resembling lymphoblasts or myeloblasts. Immunohistochemical characterization of the tumors showed expression of CD4, CD56, CD43, and CD123, whereas CD8, CD20, and MPO were negative. Immunoreactivity for CD3, which has been described in rare occasions, was found only in one of the cases. This characteristic profile in addition to the expression of CD123, which was detected in both cases, can be used as valuable tools in the diagnosis of this rare neoplasm.

CD4+/CD56+ hematodermic neoplasm: blastic NK cell lymphoma in a 6-year-old child: report of a case and review of literature

A 6-year-old girl presented with disseminated polymorphous skin lesions of several months' duration, joint pains, recurrent fever, anemia, and inguinal adenopathy. Subsequent evaluation of skin, lymph node, and bone marrow morphology showed infiltration of atypical lymphocytic cells. Immunohistochemical and flow cytometric analysis showed findings consistent with the rare but highly malignant blastic Natural killer cell lymphoma/leukemia also termed CD4/CD56 hematodermic neoplasm.

Subcutaneous panniculitis-like T-cell lymphoma: definition, classification, and prognostic factors: an EORTC Cutaneous Lymphoma Group Study of 83 cases

In the WHO classification, subcutaneous panniculitis-like T-cell lymphoma (SPTL) is defined as a distinct type of T-cell lymphoma with an aggressive clinical behavior. Recent studies suggest that distinction should be made between SPTL with an alpha/beta T-cell phenotype (SPTL-AB) and SPTL with a gammadelta T-cell phenotype (SPTL-GD), but studies are limited. To better define their clinicopathologic features, immunophenotype, treatment, and survival, 63 SPTL-ABs and 20 SPTL-GDs were studied at a workshop of the EORTC Cutaneous Lymphoma Group. SPTL-ABs were generally confined to the subcutis, had a CD4-, CD8+, CD56-, betaF1+ phenotype, were uncommonly associated with a hemophagocytic syndrome (HPS; 17%), and had a favorable prognosis (5-year overall survival [OS]: 82%). SPTL-AB patients without HPS had a significantly better survival than patients with HPS (5-year OS: 91% vs 46%; P<.001). SPTL-GDs often showed (epi)dermal involvement and/or ulceration, a CD4-, CD8-, CD56+/-, betaF1- T-cell phenotype, and poor prognosis (5-year OS: 11%), irrespective of the presence of HPS or type of treatment. These results indicate that SPTL-AB and SPTL-GD are distinct entities, and justify that the term SPTL should further be used only for SPTL-AB. SPTL-ABs without associated HPS have an excellent prognosis, and multiagent chemotherapy as first choice of treatment should be questioned.