Cutaneous involvement in lymphoblastic lymphoma

Atypical Presentation of B-Cell Lymphoblastic Lymphoma: Solitary Scalp Mass in a Pediatric Patient

B-cell lymphoblastic lymphoma (B-LBL) is a subtype of non-Hodgkin lymphoma characterized by the proliferation of abnormal B-cell lymphoblasts in lymphoid tissues. Typical presentations include lymphadenopathy, mediastinal mass, and involvement of organs such as the liver and spleen, but extranodal sites can also be affected. A previously healthy 20-month-old male child presented to the pediatric surgery clinic with a two-month history of a painless, progressively enlarging mass on the scalp as well as postauricular mass consistent with an enlarged lymph node. Ultrasound of the mass near the vertex demonstrated a hypoechoic complex cystic lesion for which excision was indicated. Preoperatively, acute enlargement of the entire postauricular lymphatic chain was noted. Intraoperatively, the scalp mass was noted to be firm with calcified tissue and no identifiable cystic or infectious components. The mass and part of the overlying skin were excised. Pathologic evaluation was consistent with B-LBL. The patient was therefore referred to a pediatric oncologist for further evaluation and management. Bone marrow examination revealed greater than 25% blasts in the clot section, consistent with B-ALL. He was promptly initiated on induction therapy with maintenance chemotherapy to ensure continued remission. This case highlights the atypical presentation of B-cell lymphoblastic leukemia/lymphoma (B-ALL/LBL) as a scalp mass in a 20-month-old male. It underscores the importance of considering malignancy in the differential diagnosis of unusual masses. Prompt collaboration between pediatric surgeons and oncologists facilitates timely diagnosis and initiation of appropriate treatments for optimal outcomes.

Skin Involvement by Hematological Neoplasms with Blastic Morphology: Lymphoblastic Lymphoma, Blastoid Variant of Mantle Cell Lymphoma and Differential Diagnoses

Hematological neoplasms sharing a blastic morphology may involve the skin. The skin may be either the primary site of occurrence of hematological malignancies with blastic features or cutaneous lesions are the first manifestation of an underlying systemic malignancy. The assessment of skin biopsies of hematological neoplasms with blastic features poses diagnostic problems and requires expert hematopathologists considering a wide range of differential diagnoses. The precise diagnosis of diseases sharing blastic features but with different outcomes and requiring distinct therapies is essential for patient management. The present paper mainly focuses on cutaneous involvement of the blastoid variant of mantle cell lymphoma and lymphoblastic lymphoma of B-cell or T-cell origin. The relevant literature has been reviewed and the clinical aspects, pathological features, prognosis, and therapy of both blastoid mantle cell lymphoma and lymphoblastic lymphoma involving the skin are discussed. A focus on other hematological entities with blastic features, which may involve the skin, to be taken into consideration in differential diagnosis is also given.

T-Cell Lymphoblastic Lymphoma with Cutaneous Involvement in a Child: A Rare Case Report

T-cell lymphoblastic lymphoma (T-LBL) is a heterogeneous malignancy derived from T-cells that more commonly affects teens and males. Most commonly, T-LBL exhibits signs of lymph nodes, bone marrow, and mediastinal mass invasion, but in rare cases, the disease manifests cutaneously. We present a case of both cutaneous and systemic presentation of T-LBL in 9-year-old man in which the skin immunophenotype analysis showed TdT expression with positivity of CD3, CD4 and CD99. Review of all currently described cases of cutaneous T-LBL revealed that the most frequently positive tumor markers were TdT (100%), CD3 (100%), CD4 (59.1%) and CD99 (40.9%). Cutaneous involvement may be a prognostic factor in treating T-LBL with chemotherapy.

A case of conjunctival precursor T cell lymphoblastic lymphoma presenting with salmon colored conjunctival mass

Purpose

Observations

Conclusions and importance

Navigating the cutaneous B-cell lymphomas: avoiding the rocky shoals

In recent years great progress has been made in understanding the classification of lymphomas. The integration of morphologic, clinical, immunophenotypic, and molecular features provides a rational basis for defining disease entities and has led to worldwide consensus. Hematopathologists and dermatopathologists have worked together to define those lymphomas that are present most commonly in the skin. Some cutaneous lymphomas have distinctive features and differ from their nodal counterparts. This is most evident in the delineation of primary cutaneous follicle center lymphoma and primary cutaneous marginal zone lymphoma. Both are very indolent, with low risk to spread beyond the skin. Primary cutaneous marginal zone lymphoma shows evidence of immunoglobulin class switching, as distinct from involvement by other extranodal marginal zone lymphomas of MALT type, which may involve the skin secondarily. Some have suggested that primary cutaneous marginal zone lymphoma may be considered a benign clonal expansion, probably driven by antigen. Many cutaneous lymphomas share biological and clinical features with their systemic counterparts. For example, primary cutaneous large B-cell lymphoma, leg type, exhibits a similar gene expression and molecular profile as diffuse large B-cell lymphoma of the activated B-cell type, especially for those cases arising in other extranodal sites. In addition, Epstein-Barr virus plays a role in many cutaneous lesions including mucocutaneous ulcer, plasmablastic lymphoma, and even some cases of marginal zone lymphoma. These EBV-driven conditions may present primarily in the skin, but also involve other mainly extranodal sites. Thus, it is evident that some cutaneous and systemic lymphomas are driven by common pathogenetic mechanisms, necessitating an integrated approach for the classification of lymphoma in all sites.

Cutaneous B-Cell Lymphoblastic Lymphoma

B-cell lymphoblastic lymphoma (B-LBL) is a malignant neoplasm of immature B cells that accounts for only 10% of all cases of lymphoblastic lymphoma. Most commonly, B-LBL presents as bony lesions, but in rare cases, the disease manifests cutaneously. We present a case of simultaneous cutaneous and systemic presentation of B-LBL in an otherwise healthy 28-year-old man in which the lymphoblastic infiltrate stained positive for CD79a, Tdt, CD10, and CD20. A diagnosis of cutaneous B-LBL was made, and systemic work-up revealed widespread involvement of the skin, bone, and lymph nodes. Review of all currently described cases of cutaneous B-LBL with or without systemic involvement revealed that the most frequently positive tumor markers were CD79a (92.3%), Tdt (90.6%), and CD10 (83.3%). Systemic involvement of B-LBL was found in nearly half of all cases with cutaneous presentation.

Primary Cutaneous T-Cell Lymphoblastic Lymphoma: Case Report and Literature Review

Cutaneous involvement by precursor T-cell lymphoblastic leukemia/lymphoma (T-ALL/LBL) is rare, and almost all cases are seen in association with bone marrow, blood, and/or lymph node involvement. Presentation with isolated skin involvement is very rare. Literature review revealed only one case report of primary cutaneous T-cell LBL. We discuss here another patient diagnosed with primary cutaneous T-cell LBL at our institute. This patient was initially misdiagnosed as having peripheral T-cell lymphoma NOS. Cytogenetic analysis showed the CDKN2A deletion (−9p21×2) in addition to three intact copies of ABL1 (+9q34). Although she failed multiple lines of intensive chemotherapy, her disease remained confined to the skin. We believe that this presentation of T-LBL is underreported, and many patients are likely misdiagnosed as having high-grade cutaneous T-cell lymphomas. With this case and literature review, we would like to highlight the importance of keeping lymphoblastic lymphoma on the differential diagnosis of cutaneous T-cell lymphoma-like lesions to avoid delay in diagnosis and inappropriate treatment of this aggressive disease.

Primary Non-Hodgkin Lymphoma of Skeletal Muscle Coexistence with Cutaneous Infiltration

This report describes a no-Hodgkin lyphoma case presenting with skeletal muscle and cutaneous involvement. A 75 year-old man was admitted to hospital with mass in the right upper extremity and skin lesions on the back of his trunk. Excisional mass biopsy was reported immunohistopthologically as large B-cell lymphoma. Primary extranodal lymphoma arising from skeletal muscle and concomitant skin infiltration of other body localization is not common. So this case was represented and relevant literature was reviewed.

Cutaneous involvement as the first manifestation of T-lymphoblastic lymphoma and review of the literature

Lymphoblastic lymphomas (LBLs) are uncommon malignant neoplasms derived from immature T- or B-lymphoid progenitor cells. Although cutaneous involvement may reach 33% in B-LBL, only 12 cutaneous cases of T-LBL have been published. We report the case of a 49-year-old woman with 2-month history of erythematous-violaceous plaques in the sternal region and breasts. Histopathologic examination showed a dense monomorphus infiltrate in dermis and positive immunostainings for CD3, CD99 and terminal deoxynucleotidyl transferase, thus indicating T-LBL. Staging work-up only revealed a mediastinal mass at diagnosis. After a 51-month follow-up and different treatment regimens, the patient remains alive although she has presented four relapses, all of them extramedullary.

[Cutaneous involvement in T-lymphoblastic lymphoma]

BACKGROUND

Lymphoblastic lymphoma (LBL) is a rare form of non-Hodgkin's lymphoma (NHL). Cutaneous LBL is seen in less than 20% of patients.

PATIENTS AND METHODS

Herein, we report the case of a 66-year-old male patient without any previous disease history of note and who was presenting a gradually spreading tumoral lesion of the scalp, several purplish macules and nodules on the trunk, and a single spinal adenopathy. A thoracic-abdominal-pelvic CT scan performed for acute renal failure, revealed extensive infiltration of retroperitoneal tissue. Skin biopsies and staging tests indicated LBL-T with associated cutaneous, bone and lymph node retroperitoneal lesions with no mediastinal mass. After two months of treatment with CHOP (four courses), the cutaneous lesions and abdominal tumoral mass had regressed and renal function had returned to normal.

DISCUSSION

There have been 13 reported cases of LBL with cutaneous involvement; most of these patients were young (under 30 years) and presented multiple cutaneous lesions (nodules or tumors) associated with numerous peripheral adenopathies, invasion of the bone marrow, and in many cases, a mediastinal mass. The clinical presentation of LBL-T in our case is novel on account of the cutaneous sites, associated with abdominal tumoral syndrome, without mediastinal infiltration, and with a single peripheral adenopathy, in an elderly subject.

Primary Cutaneous Lymphomas in Children and Adolescents

Primary cutaneous lymphomas are rare in children and mostly represented by mycosis fungoides and CD30(+) lymphoproliferative disorders. Most pediatric cutaneous lymphomas have similar clinical/pathological features as their adult counterparts, particularly the T-cell subtypes. With regard to outcome, adult cutaneous mature T-cell lymphomas have a tendency to progression, while this appears to be relatively infrequent in children. The outcome of cutaneous B-cell lymphomas depends on subtype, with the B-lymphoblastic entity being associated with similar outcomes to precursor B acute lymphoblastic leukemia, while there are insufficient data on other entities. The diagnosis and treatment of these patients require a close collaboration between experienced pediatric pathologists, dermatologists, and oncologists. Prospective collection of longitudinal clinical and biological data from children with these rare lymphomas is needed to better understand their biological and clinical behavior and to ultimately discover the best therapeutic strategies.

The progression of CD56+ myeloid sarcoma: A case report and literature review

The current study presents a case of cluster of differentiation (CD)56⁺ myeloid sarcoma in a patient that initially presented with skin lesions, and provides evidence for the clinical and differential diagnosis of myeloid sarcoma. The patient of the present case report was a 65-year-old man who was admitted to hospital with a six-month history of bilateral purple-red papules and nodules, which were present on the upper limbs of the patient and had spread over his whole body one month prior to admission to the hospital. Pathological examination demonstrated a diffuse infusion of primitive round cells at the papillary dermis and subcutaneous tissues. The infiltrated cells were 40-60 µm in diameter and morphologically identical. Immunohistochemical examination revealed that the cells expressed myeloperoxidase, CD56, CD43 and T-cell intracytoplasmic antigen. In addition, several cells expressed CD34, and 90% of the cells expressed Ki67. While the majority of cells in myeloid sarcoma do not express CD56, the present case was a myeloid sarcoma that expressed CD56, which is extremely rare. The sarcoma in the present patient progressed rapidly, and the patient died eight months following the onset of disease. Clinicians should be aware of CD56⁺ myeloid sarcoma, which is easily misdiagnosed and inappropriately treated. Consequently, myeloid sarcoma may have a high malignancy and poor outcome for patients.

T-lymphoblastic lymphoma with cutaneous involvement

To study dermatological manifestation of T-lymphoblastic lymphoma and to help clinicians in the diagnosis, we report here the case of a 75-year-old patient who presented with violaceous nodules acquired during the last 4 wk and affecting the scalp and right arm. The diagnosis of systemic lymphoma was suggested upon the appearance of cutaneous tumors, palpable lymph nodes and general symptoms including asthenia and weight-loss. The pathology features: positive immunostaining for CD3 and terminal deoxynucleotidyl transferase (TdT) and staging, led us to the final diagnosis of T-lymphoblastic lymphoma (T-LBL) with cutaneous involvement. He received a CHOP regimen as first-line treatment. Unfortunately, the patient relapsed and died 8 mo after the treatment initiation. T-LBL may be diagnosed by skin lesions. Additional immunostaining including TdT and experienced histopathologists are needed to correctly classify this aggressive disease and discuss the correct management including bone-marrow transplantation where appropriate.

Precursor B- or T-lymphoblastic lymphoma presenting with cutaneous involvement: a series of 13 cases including 7 cases of cutaneous T-lymphoblastic lymphoma

BACKGROUND

Lymphoblastic lymphoma (LBL) is a rare neoplasm of precursor lymphocytes, and cutaneous involvement is present in less than 20% of cases.

OBJECTIVE

We sought to describe the clinical and histopathological features of cutaneous LBL.

METHODS

We retrospectively examined the clinical and histologic features of 13 patients with cutaneous LBL, 6 with B-LBL and 7 with T-LBL.

RESULTS

Five of 6 patients with B-LBL had lesions in the head and neck area, whereas 4 of 7 patients with T-LBL developed skin lesions on sites other than the head and neck. Seven patients (1 case of B-LBL, and 6 of 7 cases of T-LBL) developed multiple skin lesions, and the T-LBL cases frequently developed multiple skin lesions in the head, neck, and throughout the torso. Complete remission was achieved in 9 patients (3 patients with T-LBL and all patients with B-LBL).

LIMITATIONS

This study used a retrospective design and included a small sample size.

CONCLUSION

This study compared the clinical features of T-LBL and B-LBL, in particular the affected sites and number of skin lesions. Cutaneous T-LBL is likely to be accompanied by disseminated disease and has a relatively poor prognosis compared with B-LBL.

Primary cutaneous B-cell lymphoblastic lymphoma in an elderly man

Precursor B-cell lymphoblastic lymphoma (B-LBL) is an uncommon high-grade neoplasm of immature B cells. It occurs predominantly in childhood with extranodal involvement such as skin and bone. Therefore, primary cutaneous involvement in elderly adults is a very rare manifestation of B-LBL. Here, we report a 78-year-old man with B-LBL presenting as a single cutaneous lesion which was immunohistochemically positive for leukocyte common antigen (LCA), CD79a, paired box 5 (PAX5), B cell lymphoma-2 (bcl-2), and terminal deoxynucleotidyl transferase (TdT) staining, but was without systemic involvement. The patient was treated using cyclophosphamide, adriamycin, vincristine, and prednisolone (CHOP), and achieved complete response (CR) at the first response assessment conducted after 3 CHOP cycles. After an additional cycle of CHOP treatment, radiotherapy was administered at a total dose of 3,600 cGy over 4 weeks. At the 21-month follow-up, he had maintained CR.

Three cases of primary cutaneous lymphoblastic lymphoma: microarray-based comparative genomic hybridization and gene expression profiling studies with review of literature

Lymphoblastic lymphoma (LBL) is a neoplasm of precursor B- or T-lymphocytes, and primary skin involvement is uncommon. The aim of the study was to review all reported primary cutaneous (PC)-LBLs and to examine three new cases to better characterize this neoplasm. Two of our patients showed a pre-B phenotype (PC-B-LBL) and one a never-reported pre-T phenotype (PC-T-LBL). The patient with PC-T-LBL showed an aggressive course, while those with PC-B-LBL showed a complete remission (CR) after polychemotherapy. Cytogenetic analysis and gene expression profiling (GEP) were performed on one case of PC-B-LBL and on that of PC-T-LBL. A specimen of PC-B-LBL and two specimens (early and late stage) of PC-T-LBL were investigated by microarray-based comparative genomic hybridization (CGH). All specimens revealed trisomy of chromosome 4. PC-T-LBL showed a gain of 1p36.33-p22.1 in the early stage and multiple chromosome gains/losses in the late stage. Our data suggest that trisomy 4 could be detected early in LBL and gain of 1p36.33-p22.1 could be an interesting marker in PC-T-LBL. LBL is an aggressive disease but, only in B-LBL, the cutaneous presentation seems to be a favorable prognostic factor and polychemotherapy is the best therapeutic approach. We suggest that PC-LBL should be included as a provisional clinicopathologic entity in future cutaneous lymphoma classification.

When dead cells tell tales-cutaneous involvement by precursor T-cell acute lymphoblastic lymphoma with an uncommon phenotype

The thymic type of precursor T-cell acute lymphoblastic lymphoma (pre-T ALL), an uncommon T-cell malignancy, typically presents as a thymic mass and expresses terminal deoxonucleotidyl transferase, CD7, and cytoplasmic CD3, with variable expression of other markers. Cutaneous presentation in pre-T ALL is highly unusual. We describe a case of pre-T ALL presenting as 2 papulonodular lesions on the face of an otherwise asymptomatic 27-year-old man. Microscopic examination of both lesions revealed a moderate to dense pandermal infiltrate of medium-sized lymphocytes with extensive "crush" artifact, whereas immunohistochemistry revealed positive staining of lesional cells for CD45, CD3, Bcl-2, Ki-67, CD5, CD7, and CD34 but negative staining for CD4, CD8, CD30, CD56, CD10, CD117, anaplastic lymphoma kinase protein, TdT, myeloperoxidase, CD79a, and CD20. Gene rearrangement studies performed on both biopsies identified a clonal population of T lymphocytes. A subsequent computed tomography scan revealed a 9-cm mediastinal mass encasing all major mediastinal vessels, whereas a bone marrow biopsy revealed blasts with an immunophenotype similar to that of the cutaneous lesions. Features unique to this case include the cutaneous presentation and the immunophenotype-absence of CD4, CD8, and TdT with expression of CD34-both highly unusual features for pre-T ALL.

CD34-reactive tumors of the skin. An updated review of an ever-growing list of lesions

Over the past few years, a growing number of cutaneous tumors expressing CD34 is being reported. The list contains benign and malignant neoplasms as well as reactive and hamartomatous lesions of diverse lineages of differentiation, including fibroblastic, myofibroblastic, fibrohistiocytic, vascular, neural, adipocytic, smooth muscle, hematopoietic, melanocytic and epithelial. The more frequent diagnostic difficulties are found in spindle cell proliferations, mainly in those of the fibrocytic lineage. In part, this is because of the fact that in this area are, aside to well-defined entities, histologically and clinically diverse, recently reported cutaneous CD34-reactive lesions, whose definitions, limits and relationships are not completely established. The CD34 expression plays a key role in the differential diagnosis of some tumors, such as dermatofibrosarcoma protuberans, epithelioid sarcoma or pleomorphic hyalinizing angiectatic tumor of soft parts, with important therapeutic consequences. In others, as in desmoplastic trichilemmoma, it can help to resolve diagnostic problems in concrete cases. Finally, in many of the CD34-positive lesions, the diagnosis with the hematoxylin and eosin stain is straightforward. However, in all of them, the knowledge of the immunohistochemical profile contributes to our understanding of the cutaneous pathology.

Epidermotropic Precursor T-cell Lymphoma With Highly Aggressive Clinical Behavior Simulating Localized Pagetoid Reticulosis

We describe a 43-year-old patient with a solitary, eczematous plaque on his right nipple that had developed during the previous 6 weeks. Histopathology revealed a superficial band-like infiltrate of medium to large-sized pleomorphic lymphocytes with striking epidermotropism. The tumor cells expressed a T-phenotype (CD3+, CD20-) and were CD30-, CD4-, and CD8-negative. A diagnosis of localized pagetoid reticulosis (Woringer-Kolopp disease) with possible large cell transformation was proposed. A cervical lymph node excised 2 months later showed features of a highly aggressive blastoid precursor T-cell lymphoma. Reevaluation of the skin lesion and of a tonsil specimen previously interpreted as benign hyperplasia showed features consistent with those observed in the lymph node. The disease was rapidly progressive, and the patient died 15 months after the first skin biopsy. This case represents a unique cutaneous presentation of aggressive precursor lymphoma, showing the protean nature of lymphoproliferative disorders and the overlapping clinical and histopathologic features of different entities.

Superficial primitive neuroectodermal tumor/Ewing sarcoma (PN/ES): same tumor as deep PN/ES or new entity?

Primitive neuroectodermal tumor/Ewing sarcoma (PN/ES) is a single clinical, morphologic, and molecular small round cell tumor entity. These are generally found in deep soft tissue or bone of young male patients, with poor behavior. Location in dermis is unexpected; only rare cases are reported. Cases coded as "dermal," "cutaneous," or "skin" PN/ES were retrieved from our consultation files. Only primary dermal cases were included. Those otherwise diagnosed or with incomplete material were excluded. There were 13 dermal PN/ES cases, consisting of 10 women and 3 men. Ages ranged from 2 to 67 years (mean, 28 years). Locations included groin or thigh (4), back or shoulder (3), neck (1), chest (1), scalp (1), forehead (1), hand (1), and foot (1). Most cases were small (0.5-2.3 centimeters) and painful, and persisted for less than 1 year. All were located within the dermis. Three caused pedunculation; 9 also involved superficial subcutis. All but 1 of the metastasizing tumors were round and encapsulated. All were composed of round to oval cells with a vague rosetting pattern, slightly overlapping nuclei, finely stippled chromatin, clear to eosinophilic cytoplasm, and collagenous stroma. Median mitotic activity was 8 per 10 high-power fields. Necrosis was present in three cases. All had globular periodic acid Schiff positivity and distinctive cytoplasmic membrane CD99 reactivity. One case studied was positive for Fli-1. All were negative for leukocyte common antigen, Tdt, CD3, CD20, CD79, CK20, pankeratin, epithelial membrane antigen, chromogranin, neurofilament protein, carcinoembryonic antigen, desmin, actin, diffuse S100 protein, and HMB45. Nine cases with material for reverse transcription-polymerase chain reaction revealed 1 positive type 2 translocation (EWS exon 7 to Fli-1 exon 5), 4 negative, and 4 "unable to amplify." Treatment was by wide excision; 9 received chemotherapy and 6 radiation. Follow-up of 11 (85%) cases revealed the following: 1 metastasis to stomach and death at 3 years; 10 years without disease (median, 9.0 years). Cutaneous PN/ES is a superficial round cell tumor in older women, with better prognosis than deep PN/ES. These may have a hitherto unrecognized variant genetic abnormality.

Lymphoproliferative lesions of the skin

Diagnosis and differential diagnosis of cutaneous lymphoproliferative disorders is one of the most difficult areas in dermatopathology, and biopsies are often taken to rule out a cutaneous lymphoma in patients with "unclear" or "therapy-resistant" skin lesions. Histopathological features alone often enable a given case to be classified to a diagnostic group (eg, epidermotropic lymphomas), but seldom allow a definitive diagnosis to be made. Performing several biopsies from morphologically different lesions is suggested, especially in patients with suspicion of mycosis fungoides. Immunohistochemistry is often crucial for proper classification of the cases, but in some instances is not helpful (eg, early lesions of mycosis fungoides). Although molecular techniques provide new, powerful tools for diagnosing cutaneous lymphoproliferative disorders, results of molecular methods should always be interpreted with the clinicopathological features, keeping in mind the possibility of false positivity and false negativity. In many cases, a definitive diagnosis can be made only on careful correlation of the clinical with the histopathological, immunophenotypical and molecular features.

Precursor B-cell lymphoblastic lymphoma involving the skin

Precursor B-cell lymphoblastic lymphoma (B-LBL) is a rare neoplasm composed of immature lymphocytes that demonstrate lymphoblastic morphology and express precursor and B-cell marker. It usually affects people of younger age group and causes multiple nodules on the head and neck area. The neoplasm is rare in old age. We report a case of B-LBL occurring in a 65-year-old man. He presented with multiple skin nodules on the scalp, the neck and the arm for 2 months. Histopathologic examination demonstrated diffuse dermal and subcutaneous monotonous infiltrates of medium-sized lymphoid cells with starry-sky pattern. Immunohistochemical study showed that the lymphoid cells of infiltrate showed precursor B-cell type. The patient has received combination chemotherapy three times and is being followed-up at the outpatient clinic.

The spectrum of cutaneous lymphomas in patients less than 20 years of age

Cutaneous lymphomas are rare in young patients and are mostly represented by mycosis fungoides and its variants and CD30+ lymphoproliferative disorders (lymphomatoid papulosis [LYP] and anaplastic large T-cell lymphoma). We report our observations in a series of 69 patients less than 20 years of age who presented either with primary cutaneous lymphoma (n = 62) or with secondary manifestations of extracutaneous disease (n = 7). Clinicopathologic features permitted classification of the cases into the following diagnostic categories: mycosis fungoides (n = 24, all primary cutaneous), anaplastic large T-cell lymphoma (n = 13, all primary cutaneous), LYP (n = 11, all primary cutaneous), subcutaneous "panniculitis-like" T-cell lymphoma (n = 1, primary cutaneous), small-medium pleomorphic T-cell lymphoma (n = 2, all primary cutaneous), natural killer (NK)/T-cell lymphoma, nasal-type (n = 1, secondary cutaneous), follicle center cell lymphoma (n = 1, primary cutaneous), marginal zone B-cell lymphoma (n = 7, all primary cutaneous), B-lymphoblastic lymphomas (n = 6, 3 primary and 3 secondary cutaneous), specific cutaneous manifestations of Hodgkin disease (n = 1, secondary cutaneous), and acute myeloid leukemia (n = 2, both secondary cutaneous). Cutaneous lymphoma in children should be differentiated from benign skin disorders that may simulate them. In particular, mycosis fungoides and LYP in this age group may present with clinicopathologic features reminiscent of inflammatory disorders such as pityriasis alba, vitiligo, pityriasis rosea, and pityriasis lichenoides et varioliformis acuta. Even in secondary cutaneous lymphomas, skin manifestations may be the first sign of the systemic disease, and a diagnosis may be achieved on examination of histopathologic specimens of a cutaneous lesion. Our study illustrates the wide spectrum of cutaneous lymphomas and leukemias in patients less than 20 years of age and underlines the need for proper interpretation of these lesions by dermatologists and dermatopathologists.

Hydroa-like cutaneous T-cell lymphoma: a clinicopathologic and molecular genetic study of 16 pediatric cases from Peru

Hydroa-like cutaneous T-cell lymphoma (hydroa-like CTCL) is an unusual pediatric malignancy with a poor prognosis. An impressive cutaneous rash characterized by edema, blisters, ulcers, crusts, and scars, resembling hidroa vacciniforme, is seen mainly on the face and sometimes on the extremities. The lesion consists of lymphomatous T-cell infiltration of the skin and subcutis with variable exocytosis and angiocentricity. It has been also called edematous, scarring vasculitic panniculitis and hydroa-like lymphoma. An association with Epstein-Barr virus has been suggested. The differential diagnosis includes other cutaneous lymphomas, particularly the cutaneous nasal type T/natural killer-cell lymphoma, mycosis fungoides, precursor T-cell lymphoblastic lymphoma, nonspecific peripheral T-cell lymphoma, cutaneous anaplastic large cell lymphoma, and subcutaneous panniculitic T-cell lymphoma. Other differential diagnoses are inflammatory dermatopathies and panniculitides. Based on a series of 16 such cases referred to the Institute of Neoplastic Diseases, the objective of this report is not only to provide a better clinicopathologic understanding of this entity but also a reappraisal of it as a malignancy. The male/female frequency ratio was 1:1. The median age was 10 years old. All cases showed predominant facial involvement with edema, blisters, ulcers, crusts, and scars. Chemotherapy and/or radiotherapy had little or no benefit. The prognosis was usually dismal. The lymphoma extended from the epidermis to the subcutis, with frequent angiocentric and periadnexal array. Lymphoma cells were mostly of intermediate size with dense hyperchromatic nuclei, inconspicuous nucleoli, and infrequent mitosis. A scanty and variable inflammatory background was found. The lymphoma cells displayed T-cell cytotoxic phenotype. In addition, they were negative for the natural killer cell antigens CD56 and CD57. Epstein-Barr virus in situ hybridization was positive in the six cases in which it was assayed. T-cell receptor gamma (TCRgamma) displayed monoclonal-type rearrangement in four cases studied. Our findings indicate that hydroa-like CTCL is an independent clinicopathologic entity that affects children. Consequently, it should be considered an independent subset of CTCLs and be included as such in the classification of neoplastic diseases of the lymphoid tissues.

Primary cutaneous lymphoblastic lymphoma presenting in an 8-week old infant

BACKGROUND

We report a case of primary cutaneous lymphoblastic lymphoma (LBL) presenting in an 8-week-old infant.

METHODS

Histopathology and flow cytometric analysis confirmed the diagnosis of a lymphoblastic lymphoma. The cells expressed CD19, CD20, CD34 and surface immunoglobulin (sIg).

RESULTS

The cells were negative for TdT and CD99. This unusual immunophenotype has been described as "transitional pre-B-cell", in that the cells express both immature markers (CD34) and mature markers (sIg).

CONCLUSIONS

To our knowledge, only five other cases of sIg positive precursor B-cell LBL have been reported in the literature. This may represent the youngest reported case of primary cutaneous LBL, occurring at 8weeks of age.

Cutaneous lymphoblastic lymphoma in children: report of six cases with precursor B-cell lineage

Precursor B lymphoblastic lymphomas (B-LBL) are generally rare, but appear to have a higher incidence in children than in adults. In this report, we describe in detail six cases of B-LBL presenting with cutaneous lesions. Three occurred in the scalp, one in the skin of the thigh, one in the skin of the face and breast, and one in the subcutaneous tissue of the orbit. All six patients are females ranging in age at presentation from 5 to 15 years (mean = 9.6). None of the cases had bone marrow involvement, while two had bone involvement (maxilla, distal tibia, and distal humerus in one case, and distal tibia and orbital bone in another case); only one case had lymphadenopathy (retroperitoneal). Immunohistochemical staining showed positivity for CD79a and CD43 in all six cases. LCA and L26 positivity were also each seen in one case. Staining for MIC-2 (CD99) showed strong positivity in three cases. Vimentin was positive in four cases and TdT was positive in all five patients tested. Staining for keratin, UCHL-1, or CD30 was not encountered. Cases in which cell marker studies by flow cytometry were performed showed positivity for CD10, CD19 with negative CD20, pan-T-cell, and myeloid markers. The five patients who received multiagent chemotherapy are alive with follow-up intervals of 2 to 18 years. Two patients had local recurrences and were given radiation therapy (one with repeating multiagent chemotherapy). One patient (diagnosed in 1962) died of disseminated disease; she had been treated with radiation therapy and 6MP only. Cutaneous B-LBL must be included in the differential diagnosis of small blue cell tumors, especially in children. In contrast to its T-cell counterpart, B-LBL occurs more frequently in females, tends to present as skin or bone lesions, and is associated with a potential cure, even in cases that relapse.

Immunohistochemical detection of FLI-1 protein expression: a study of 132 round cell tumors with emphasis on CD99-positive mimics of Ewing's sarcoma/primitive neuroectodermal tumor

The histologic and immunohistochemical differentiation of Ewing' s sarcoma/primitive neuroectodermal tumor (ES/PNET) from other small, blue, round cell tumors may be difficult. Despite initial promise, CD99 (MIC2) has not proven to be a specific marker. Approximately 90% of ES/PNET have a specific t(11; 22)(q24;q12) that results in fusion of the EWS and FLI-1 genes, and overexpression of FLI-1 protein. A recent study has shown immunohistochemical FLI-1 expression in five of seven of the ES/PNET cases tested. We evaluated FLI-1 expression in 132 well-characterized small, blue, round cell tumors. All tumors were immunostained for FLI-1 (1:40, Sc 356 polyclonal, Santa Cruz Biotechnology) using steam heat for epitope retrieval. Only nuclear staining was accepted as positive. Endothelial cells were strongly positive in all cases and served as an internal control. In many cases, a subset of lymphocytes also stained positive. No staining was seen in any other normal tissue. FLI-1 expression was seen in 29 of 41 (71%) ES/PNET, 7 of 8 (88%) lymphoblastic lymphomas, 0 of 8 poorly differentiated synovial sarcomas (PDSS), 0 of 32 rhabdomyosarcoma (RMS), 0 of 30 neuroblastomas, 0 of 8 esthesioneuroblastomas, 0 of 3 Wilms' tumors, 0 of 1 mesenchymal chondrosarcoma, and in 1 of 1 desmoplastic round cell tumor. This last case was known to have an EWS/WT-1 fusion. Although the EWS/FLI-1 fusion gene is specific for ES/PNET, FLI-1 protein expression is not. Significantly, the great majority of lymphoblastic lymphomas (also CD99-positive) are strongly FLI-1-positive. Immunohistochemical detection of FLI-1 may be valuable in confirming the diagnosis of ES/ PNET in cases in which molecular genetic evaluation is not feasible. FLI-1 protein expression is also helpful in distinguishing ES/PNET from other tumors that may be CD99-positive, such as PDSS and RMS. It is not surprising that some ES/ PNET are FLI-1-negative, because not all ES/PNET have the classic EWS/FLI-1, and some cases of ES/PNET may produce either low levels of protein or idiotypically different protein.

Precursor B-cell lymphoblastic lymphoma: a predominantly extranodal tumor with low propensity for leukemic involvement

Precursor B-cell lymphoblastic lymphoma (B-LBL) is uncommon and accounts for less than 10% of cases of lymphoblastic lymphoma. We collected 25 cases of B-LBL, occurring in children and adults, and report the clinical and histologic features. Patients with concurrent precursor B-cell acute lymphoblastic leukemia (B-ALL) or a history thereof were excluded. There was no evidence of bone marrow disease at the time of diagnosis in 23 patients; two patients had focal (<5%) involvement. Immunophenotypic analysis was performed in all cases using flow cytometry or immunohistochemical methods. The treatment and survival data available for a subset of patients with B-LBL were compared with those from a series of patients with B-ALL at our institution. The median age was 20 years (range, 5-68 yrs); 22 (88%) patients were younger than 35 years of age. There were 17 males and 8 females. The primary sites of disease were skin (nine cases), bones (five cases), soft tissue (four cases), lymph nodes, (three cases), breast (two cases), stomach and colon (one case), and mediastinum (one case). Clinical stage was stage I in 13 cases, stage II in seven cases, stage III in three cases, and stage IV in two cases. Histologically, each neoplasm was diffuse and composed of small to medium-sized lymphoid cells with blastic nuclear chromatin and a high mitotic rate. All cases were positive for B-cell antigens and terminal deoxynucleotidyl transferase. Thirteen (76.4%) of 17 cases analyzed were positive for CD10 and 13 (54.1%) of 24 cases assessed were positive for CD20. Of 14 patients with available survival data, all achieved complete clinical response after combination chemotherapy (13 patients) or surgical excision followed by local irradiation (one patient). Five (35.7%) patients subsequently relapsed, including the patient who had received only irradiation, and four of these patients died after a median survival time of 60 months. None of the patients had leukemia, although one patient developed extensive bone marrow involvement. Nine patients remained in complete remission and were alive at the last follow up (range, 6-144 months). Unlike precursor T-cell lymphoblastic lymphoma, which commonly involves lymph nodes and the mediastinum, B-LBL usually involves extranodal sites, most often the skin, and rarely presents as a mediastinal mass. With aggressive chemotherapy, patients with precursor B-LBL rarely develop leukemia and appear to have a better prognosis than do patients with B-ALL.