Adult T-cell leukemia/lymphoma with predominant bone involvement, initially diagnosed by its oral manifestation: a case report.

Adult T-cell leukemia/lymphoma (ATL/L) is a rare malignant neoplasm linked to human T-cell lymphotropic virus type 1 (HTLV-1). This virus has been identified in Japan, the Caribbean, and, more recently, Brazil. We report a case of ATL/L (lymphoma-type) affecting a 30-year-old Brazilian woman. She presented a painful and ulcerated lesion on her hard palate mucosa. Conventional radiographs and computed tomography revealed the involvement of several bones plus the lung and axillary lymph nodes. Histopathological and immunohistochemical analyses of oral biopsy confirmed a T-cell non-Hodgkin's lymphoma. Final diagnosis of ATL/L was made based on HTLV-1 positivity. She underwent multiple cycles of chemotherapy, which produced some improvement, but she died as a consequence of pulmonary and hepatic complications 4 months after the initial diagnosis. Besides the process of diagnosing and typing a malignant lymphoma, this article outlines the value of computed tomography and the necessity of performing HTVL-1 investigation in patients with a diagnosis of lymphoma of T-cell lineage.     

Adult T-cell leukemia/lymphoma. Clinical aspects

BACKGROUND DATA: Adult T-cell leukemia/lymphoma (ATL) is a malignant proliferation of activated CD4+ T lymphocytes. The disease is almost exclusively found in patients living in retrovirus HTLV-1 endemic areas. VIROLOGY: In ATL, monoclonal HTLV-1 provirus is integrated into atypical lymphocytes, called clover-leaf lymphocytes. The pathogenic mechanism leading to HTLV-1-induced leukemogenesis remains obscure. The disease generally occurs after a long latency period. FOUR CLINICAL SUBTYPES: The diversity of the clinical presentation has led to the classification of ATL into four subtypes: acute or prototype, lymphoma, chronic, and painless. In the acute form of ATL there is a tumor syndrome associated with paraneoplastic hypercalcemia and a high rate of opportunistic infections due to the immunodepression predominated by cellular immunity. CLINICAL COURSE: Prognosis is poor for the acute and lymphomatous forms with a median survival of 6 and 10 months respectively. Infectious episodes are frequent, often caused by Pneumocystis carinii, and require systematic prophylaxis. Screening for anguilulosis and prophylaxis is also necessary.     

Rationale and efficacy of CD52 targeting in HTLV-1-associated myositis

We retrospectively analysed two selected patients, referred to our Haematology Department for refractory HTLV-1 associated myositis with circulating pathologic T-cell population with ATL phenotype. They respectively presented also HTLV-1 associated Crohn-like disease and myelopathy. Muscle biopsy of both patients was analysed to determine the pathologic infiltrate. Alemtuzumab was proposed as salvage therapy. Targeting CD52 with alemtuzumab showed good efficacy on myopathy of both patients for respectively 11 and 10 months. Interestingly, this treatment showed also efficacy on circulating pathologic T-cell population and on concomitant digestive and neurological diseases. The double infected cells ablation and immunosuppressive propriety of alemtuzumab probably explains its interest in this infectious and dysimmunitary disorder. Even though alemtuzumab probably remains a suspensive treatment, its place should be assessed in controlled trial in this difficult to treat rare disease.     

Adult T-cell leukemia/lymphoma with multiple integration of HTLV-1 provirus presenting as an isolated paranasal sinus tumor: a case report

BACKGROUND: Adult T-cell leukemia/lymphoma (ATLL) is a highly aggressive T-cell lymphoma and etiologically associated with human T-lymphotropic virus type 1 (HTLV-1). Patients with ATLL commonly present with leukemic changes, systemic lymphadenopathy, and/or extranodal lesion and have very poor prognosis. METHODS AND RESULTS: We describe a rare case of ATLL presenting as an isolated paranasal mass. Southern blot analysis of the biopsied specimens demonstrated multiple integration bands of HTLV-1 provirus of different intensities. Chemotherapy resulted in complete resolution of the paranasal mass. Thereafter, the patient showed an indolent clinical course with leukemic changes and pulmonary and cutaneous ATLL lesions and remains alive more than 5 years from diagnosis. CONCLUSION: ATLL should be included in the differential diagnosis of sinonasal lymphoma, although the event is rare. Multiple HTLV-1 provirus integrations of different intensities may be indicative of good prognosis for ATLL.     

Adult T-Cell Leukemia After Deceased Donor Liver Transplantation for Acute Liver Failure: A Case Report

Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia (ATL); however, the mechanism of its development has yet to be uncovered. A few ATL cases have been reported in HTLV-1-positive recipients after living donor liver transplantation. A 57-year-old HTLV-1-positive Japanese male suffered acute liver failure due to hepatitis B infection. He was transferred to our department to undergo deceased donor liver transplantation (DDLT). Tacrolimus and mycophenolate mofetil were induced for immunosuppression. His clinical outcome was satisfactory. However, he visited his physician 3 years after DDLT reporting abdominal pain and fever. A computed tomography scan showed multiple lymph node enlargement. Lymph node biopsy and his blood sample led to a diagnosis of ATL. He was transferred to the Department of Hematology and Oncology and underwent chemotherapy. To our knowledge, this is the first report of ATL development after DDLT from an HTLV-1-positive recipient. As is the case with our previous report, the current patient had undergone liver transplant for acute liver failure. Unlike living donor liver transplantation, however, DDLT needs no hepatic growth factor for liver regeneration. This finding sheds light on the resolution of the mechanism for the development of ATL from the HTLV-1 carrier.     

Prevalence of HTLV-1 antibodies in hemodialysis patients in Japan

The southwestern region of Japan is known as a very high endemic area of human T-cell lymphotropic virus type 1 (HTLV-1), the etiologic agent for adult T-cell leukemia (ATL) and probable causative agent for tropical spastic paraparesis and its Japanese version, HTLV-1-associated myelopathy (HAM). Hemodialysis (HD) patients seem to be at high risk for HTLV-1 infection even in other regions of Japan because they sometimes receive multiple blood transfusions. We examined antibody against ATL-associated antigen (ATLA-Ab) in 1,132 HD patients, including 1,066 patients in nonendemic areas (Chubu and Tokyo) and 66 in a highly endemic area (Okinawa). The HD patients in Okinawa showed the highest prevalence, 21.2% (14/66), while those in the Chubu area showed the lowest, 1.1% (10/846), and those in the Tokyo area an intermediate value, 2.7% (6/220). The prevalence of HD patients in each area was significantly higher than that of local blood donors, reflecting an increased prevalence roughly corresponding to the respective endemic rate. The average prevalence of ATLA-Ab among the HD patients was 2.7% (30/1,132), which was similar to that of HBs antigen (3.2%). In the nonendemic areas, 15 of 16 patients with ATLA-Ab had a history of blood transfusions, showing a significant correlation to the presence of ATLA-Ab (P less than 0.01), although four had family histories related to the endemic area. The relative risk of the presence of ATLA-Ab for HD patients with a history of blood transfusions was calculated as 10.3. In the endemic area of Okinawa, the relationship to blood transfusion was not so close, probably masked by the high background prevalence.     

Renal transplantation in patients with human T-cell lymphotropic virus type 1

Background

Renal transplantation (RTx) in carriers of human T-cell lymphotropic virus type 1 (HTLV-1) has a risk of developing overt leukemia upon immunosuppression. Although there have been a few reports of such cases, it is unclear HTLV-1 carrier if patients on the modern immunosuppressants would develop HTLV-1-associated myelopathy or adult T-cell leukemia lymphoma.

Methods

We retrospectively reviewed the clinical outcomes of RTx in nine HTLV-1 carriers to assess a risk of developing leukemia from 2002 to 2011 using immunosuppression with a calcineurin inhibitor, mycophenolate mofetil (MMF), and steroid. The anti-CD25 monoclonal antibody basiliximab was used for induction. In two cases of ABO-incompatible RTx, the rituximab was also administered before RTx.

Results

The ratio of male to female subjects was 2 to 7 with an overall mean recipient age of 54.3 ± 8.1 years. We prescribed cyclosporine (n = 5) or tacrolimus (n = 4). There was only one graft loss due to the death caused by aspiration pneumonia with a functioning graft. No one developed overt leukemia with combined treatment with MMF, basiliximab and rituximab.

Conclusion

We concluded that RTx in HTLV-1 carriers could be performed using a modern immunosuppressive regimen, without the risk of developing leukemia.     

Hematological malignancies and the bone (myeloma excluded)

Bone involvement is a rare event in lymphomas, except in patients with adult T-cell leukemia/lymphoma associated with HTLVI. It is usually characterised by lytic bone lesions located in the metaphysis of long bones or in the axial skeleton. The occurrence of bone lesions reflects a progression of the disease affecting the prognosis that is related to lymphoma histologic features and staging. Bone lesions may occur in some lymphoproliferative disorders such as LLC or Waldenstrom's disease, or in myeloproliferative disorders. They may reflect a progression to a more aggressive disorder with a worse prognosis. The treatment of hematologic malignancies presenting with bone lesions and/or hypercalcemia is similar to the treatment of the systemic disease. In primary lymphomas of bone presenting with an isolated bone lesion, local treatment with radiation therapy and/or surgical ablation is required, and adjuvant chemotherapy may improve the prognosis of these located lymphomas. Glucocorticoid therapy and bisphosphonates are effective in treating associated hypercalcemia. Except for myeloma and ATL, the underlying mechanisms responsible for bone involvement in hematologic malignancies remain poorly understood. The unusual occurrence of bone lesions in these diseases probably implies distinct pathogenic mechanisms, but one can speculate that an increased expression of RANK/RANKL, the common final pathway in bone resorption, may be involved.     

Adult T-Cell Leukemia Associated with Gastric Carcinoma: Report of a Case

A 67-year-old man was admitted to our hospital with nausea and epigastralgia, and a diagnosis of smoldering type adult T-cell leukemia (ATL) associated with advanced gastric carcinoma was made. The gastric carcinoma had caused pyloric stenosis, and investigations revealed regional lymph node metastasis. The patient underwent total gastrectomy, splenectomy, cholecystectomy, and lymph node dissection with a Roux-en-Y anastomosis. Histological examination of the regional lymph nodes revealed not only metastases of gastric carcinoma, but also of ATL lymphoma, indicating a final diagnosis of advanced gastric carcinoma with locoregional lymph node due to both metastasis of the gastric carcinoma and the ATL lymphoma. Despite the administration of postoperative adjuvant chemotherapy comprised of cisplatin/adriamycin/5-fluorouracil in combination with oral etoposide and immunotherapy using ubenimex, paraplegia suddenly developed caused by the metastasis of ATL to the epidural space. Resection of this metastatic tumor for decompression of the spinal cord resulted in resolution of the paraplegia; however, the patient died about 1 month later from rapid systemic tumor growth. Received: November 8, 1999 / Accepted: September 26, 2000     

Human T-cell leukemia virus type 1 infection worsens prognosis of hepatitis C virus-related living donor liver transplantation

Severe and life-threatening donor-transmitted human T-cell leukemia virus type 1 (HTLV-1) infections after solid organ transplantation have been reported. However, in HTLV-1-infected recipients, graft and patient survival were not fully evaluated. A total of 140 patients underwent living donor liver transplantation (LDLT). Of these, 47 of 126 adult recipients showed indications of hepatitis C virus (HCV)-related liver disease. The HTLV-1 prevalence rate was 10 of 140 recipients (7.14%) and three of 140 donors (0.02%). In HCV-related LDLT, graft and patient survival was worsened by HTLV-1 infection in recipients (seven cases). The 1-, 3-, and 5-year survival rates in the HCV/HTLV-1-co-infected group were 67%, 32%, and 15%, respectively, and the corresponding rates in the HCV-mono-infected group were 80%, 67%, and 67%, respectively. Only the 5-year survival rates were statistically significant (P=0.04, log-rank method). HTLV-1 infection in recipients is also an important factor in predicting survival in HTLV-1 endemic areas.     

Early T-cell Precursor Acute Lymphoblastic Leukemia/Lymphoma

Discrete diagnostic subtypes of T lymphoblastic leukemia/lymphoma (T-cell acute lymphoblastic leukemia/lymphoma, T-ALL) have historically not been widely recognized. Recently, a novel subset with distinctive immunophenotypic, molecular, and clinical features has been proposed. Termed early T-cell precursor acute lymphoblastic leukemia (ETP-ALL), these cases seem to correspond to a very early stage of T-cell development. ETP-ALL is associated with a poor prognosis using standard protocols, and patients with ETP-ALL may benefit from intensified, alternative, or targeted therapies. Recognizing ETP-ALL and distinguishing it from other forms of acute leukemia are important elements of an up-to-date diagnostic approach to precursor T-cell neoplasms.     

Progressive renal failure due to renal invasion and parenchymal destruction by adult T-cell lymphoma

A 43-year-old patient of occult adult T-cell lymphoma (ATL) presenting with systemic illness and progressive renal failure due to lymphomatous infiltration of kidneys is described. The striking feature observed was destructive infiltration of the kidneys, by malignant CD4 cells, virtually replacing the normal renal architecture. The diagnosis of lymphoma was made by renal biopsy. Clinical features typical of ATL were hypercalcemia, lytic bone lesions, and profound wasting and inanition. The patient died rapidly despite attempted therapy. The case illustrates the potential of ATL for direct renal parenchymal destruction.     

Primary T-cell lymphoma with myelopathy associated with HTLV-1

The case of a patient who had myelopathy associated with human T-cell lymphotropic virus Type 1 (HTLV-1) for 10 years and developed a T-cell lymphoma in the cerebellum is reported. The relationship between myelopathy associated with HTLV-1 and primary T-cell lymphoma is discussed.     

Human T-cell lymphotropic virus-1-associated renal disease in Jamaican children

This report documents the clinicopathological features in two Jamaican children who presented with infective dermatitis, glomerulonephritis, renal failure and human T-cell lymphotropic virus (HTLV-1) seropositivity. Severe hypertension with hypertensive encephalopathy was the most impressive clinical feature. Histological findings from renal biopsy specimens in both cases revealed significant glomerulosclerosis with fibrosis, chronic inflammatory cell infiltrates in the interstitium, and arteriolar hypertensive changes. Membranoproliferative glomerulonephritis (MPGN) was demonstrable in case 1 and marked focal glomerulosclerosis in case 2. Case 1 developed end stage renal failure and died within 3 years of diagnosis. Case 2 remains hypertensive and in chronic renal failure. Although a causal relationship between HTLV-1 infection and renal disease cannot be proven by these two cases, it appears that renal involvement in children with HTLV-1 infection is severe, with the potential for chronic renal failure and malignant hypertension. HTLV-1 nephropathy should be suspected in children with infective dermatitis and renal disease. Received: 1 November 1999 / Revised: 21 June 2000 / Accepted: 23 June 2000     

Sinonasal lymphoma: a clinicopathologic analysis of 58 cases from the Massachusetts General Hospital.

Few large series compare lymphomas of the nasal cavity with those of the paranasal sinuses. We studied the cases of 58 patients, 34 males and 24 females, aged 7 to 92 years (mean, 57 years), who had lymphoma involving the nasal cavity or paranasal sinuses. Thirty-three patients had diffuse large B-cell lymphoma (DLBCL). Twenty-three were male and 10 were female, with an age range of 7 to 91 years (mean, 63 years); two were HIV-positive. Only 2 of 11 cases tested (one in an HIV-positive patient and one of lymphomatoid granulomatosis type) were Epstein-Barr virus (EBV)-positive. Thirty (91%) involved paranasal sinuses, 10 with nasal involvement, whereas three cases had nasal, but not sinus, involvement. At last follow-up, 16 (67%) were free of disease 7 to 169 months later (mean, 65 months), and 8 (33%) had died of disease 2 to 166 months later (mean, 45 months). Seventeen patients had nasal-type natural killer (NK)/T-cell lymphoma. There were 10 women and 7 men, aged 27 to 78 years (mean, 48 years). Thirteen of 14 were EBV-positive. Sixteen patients had nasal involvement, eight with sinus involvement. Eleven (73%) of 15 were alive and well 6 to 321 months later (mean, 139 months), three (20%) died of lymphoma 1, 11, and 12 months later, and one (7%) is alive with disease. There was one case each of marginal zone B-cell lymphoma, Burkitt's lymphoma, Burkitt-like lymphoma, peripheral T-cell lymphoma of unspecified type, and adult T-cell lymphoma/leukemia. In an additional three cases, the lymphomas were composed predominantly of large cells, but no immunophenotyping could be performed for subclassification. In 19 cases (17 DLBCLs, 1 Burkitt-like lymphoma, and 1 lymphoma of uncertain lineage), presenting symptoms included complaints related to the eyes. In 16 cases (13 DLBCLs, 1 Burkitt-like lymphoma, 1 nasal NK/T-cell lymphoma, and 1 lymphoma of uncertain lineage), the orbit was invaded by lymphoma. In our series, the most common lymphoma to arise in the sinonasal area is DLBCL, followed by nasal NK/T-cell lymphoma. Comparison of these two types of lymphoma showed that lymphomas involving sinuses without nasal involvement were predominantly DLBCLs (20 of 21), whereas nasal cavity lymphomas without sinus involvement were usually NK/T-cell type (8 of 11) (p = 0.000125). Compared with patients with DLBCL, patients with nasal NK/T-cell lymphoma were overall younger, with a lower male-to-female ratio. Lymphomas of B-cell lineage were more likely to be associated with symptoms related to the eyes (p < 0.0005) and to have extension to the orbit (p < 0.01) than were lymphomas of T- or NK-cell lineage. In contrast to results of Asian studies in which nasal NK/T-cell lymphoma has a very poor prognosis, our nasal NK/T-cell lymphomas had an outcome similar to that of DLBCL.     

Macrophage inflammatory protein-1alpha induces hypercalcemia in adult T-cell leukemia.

Hypercalcemia is observed in >80% of ATL. Serum MIP-1alpha levels were elevated in all 24 ATL with hypercalcemia but undetectable in all 10 patients with humoral hypercalcemia of malignancy with solid tumors and in 34 of 37 ATL without hypercalcemia. We propose that serum MIP-1alpha is a clinical hallmark for hypercalcemia in ATL. INTRODUCTION: High serum cytokines levels are not always associated with hypercalcemia in patients with adult T-cell leukemia (ATL), suggesting that other factors are involved in the pathogenesis of ATL patients with hypercalcemia. This study was designed to determine the role of macrophage inflammatory protein-1alpha (MIP-1alpha), a chemokine recently described as an osteoclast stimulatory factor, in ATL-associated hypercalcemia. MATERIALS AND METHODS: We measured serum interleukin (IL)-1beta, IL-6, TNF-alpha, parathyroid hormone-related protein (PTHrP), and MIP-1alpha levels in ATL patients by enzyme-linked immunosorbent assays. FACScan was used to measure the expression of RANKL on ATL cells. Osteoclast formation in cocultures of ATL cells and peripheral blood mononuclear cells (PBMCs) was evaluated by TRACP staining. RESULTS: High serum MIP-1alpha levels were noted in all 24 ATL patients with hypercalcemia and in 3 of 37 ATL patients without hypercalcemia. The elevated levels of MIP-1alpha and calcium in ATL patients decreased after effective chemotherapy, emphasizing the role of MIP-1alpha in ATL hypercalcemia. ATL cells spontaneously produced MIP-1alpha. MIP-1alpha significantly enhanced human monocyte (precursor cells of osteoclasts) migration and induced RANKL expression on ATL cells. ATL cell-induced osteoclast formation from PBMCs was inhibited by anti-MIP-1alpha antibody and osteoprotegerin. CONCLUSION: Our results suggest that MIP-1alpha can induce RANKL on ATL cells in autocrine fashion and that RANKL seems to mediate the hypercalcemic effect of MIP-1alpha in ATL. We propose that MIP-1alpha is the clinical hallmark of hypercalcemia in ATL and could be a potentially useful therapeutic target.     

Adult T-cell lymphoma/leukemia with angioimmunoblastic T-cell lymphomalike features: Report of 11 cases

In adult T-cell lymphoma/leukemia (ATLL), the neoplastic lymphoid cells are usually medium-sized to large, often with pronounced nuclear pleomorphism compatible with the diagnosis of diffuse pleomorphic peripheral T-cell lymphoma. We describe here 11 patients with the rare morphologic variant of ATLL, angioimmunoblastic T-cell lymphoma (AILT)-like type. The examined lymph nodes showed proliferation of high endothelial venules and presence of various infiltrating inflammatory cells including plasma cells and eosinophils. The lymphoma cells were medium-to-large size with clear cytoplasm. These findings were suggestive of AILT. However, immunohistochemical features of AILT, namely, CD10 and CXCL13 expression in lymphoma cells and proliferation of CD21-positive follicular dendritic cells, were not detected. Two cases were CXCR3-positive, whereas 9 expressed CCR4, which are usually positive in ATLL. All patients were positive for antiadult T-cell leukemia/lymphoma-associated antigen, which is a specific antibody for human T-cell lymphotropic virus type-I. Southern blot analysis revealed proviral DNA integration in lymphoma cells in 9 patients. The latter was not evident in the first biopsy of 2 patients but in the second biopsy obtained within several months after the first biopsy revealed definite proviral integration. Almost all patients showed aggressive clinical course and poor survival (median survival: 5 mo). This is the first report of ATLL with AILT-like morphologic features.     

Intracranial and orbital extension of a nasal cavity adult T-cell leukemia: a case report

Adult T-cell leukemia (ATL) is one kind of leukemia induced by human T lymphotropic virus type I (HTLV-I) infection. An unusual case of ATL is presented. A fifty-one-year-old male patient was admitted to our hospital because of nasal obstruction and blindness in the left eye. Imaging study revealed a mass lesion in the nasal cavity, the left paranasal sinus extending to the left orbit and intracranial frontal base. Biopsy of the mass from the paranasal sinus was carried out and the histological diagnosis was a granulomatous lesion with non-specific inflammation. The clinical impression of the lesion was lethal midline granuloma. After steroid therapy and 50 Gy of local radiotherapy, the patient's symptoms disappeared except for his blindness in the left eye. Imaging study revealed that the mass lesion had become smaller. In spite of local improvement, new lesions such as cervical lymph node swelling and multiple nodular shadows in the lung fields appeared on CT scan. Histological diagnosis of the biopsied cervical lymph node was T-cell dominant non-Hodgkin's lymphoma of the diffuse type. Serologically, anti-HTLV-I antibody was positive. Southern blot analysis of lymph node biopsy showed monoclonal proliferation of ATL cells. We made the diagnosis of our case as ATL. The patient died 16 months later despite repeated systemic chemotherapy with cyclophosphamide, vincristine, adriamycin, and prednisolone. ATL can involve the central nervous system (CNS) and manifest CNS symptoms. The neurosurgeon also should consider the CNS involvement of ATL especially in Japan.     

HHV-8-associated T-cell lymphoma in a lymph node with concurrent peritoneal effusion in an HIV-positive man

Primary effusion lymphoma (PEL) is an uncommon large cell lymphoma, usually seen in human immunodeficiency virus (HIV)-infected patients. PEL is characterized by various clinical, histomorphologic, and immunophenotypical features, and is associated with the human herpes virus 8 (HHV-8). PEL may present as either a body cavity-based lymphomatous effusion or a solid tumor mass. Most so-called "solid PEL" usually have an extranodal location; exceptionally rarely, they occur in lymph nodes. The majority of PEL consist of malignant cells of B-cell genotype; seldom they are of T-cell origin. We report a rare case of HHV-8-associated "solid PEL" of T-cell type in a 41-year-old HIV-seropositive man with a concomitant peritoneal effusion. The T-cell lymphoma was diagnosed on the basis of morphologic, immunophenotypic, and molecular findings of a lymph node biopsy. The tumor cells strongly expressed CD45R0, CD7, CD43, MUM1/IRF4, CD30, HHV-8, and EBER, and demonstrated a clonal rearrangement of T-cell receptor-gamma chain gene. The following case provides another example of a lymph node-based "solid" PEL, demonstrating the variety within the spectrum of HHV-8-associated lymphoma.     

The pathologic spectrum of adult T-cell leukemia/lymphoma in the United States. Human T-cell leukemia/lymphoma virus-associated lymphoid malignancies

The human T-cell leukemia/lymphoma virus (HTLV) is a novel Type-C retrovirus isolated from patients with post-thymic T-cell malignancies. Thirteen patients diagnosed in the United States were identified as having antibodies to HTLV and a typical clinicopathologic syndrome characteristic of adult T-cell leukemia/lymphoma as described in Japan. The most characteristic diagnostic feature in our series was the presence of highly pleomorphic and lobated lymphoid cells in the peripheral blood. Also notable was acid phosphatase activity which was partially tartrate-resistant in the neoplastic cells. The pathologic spectrum of the associated lymphomas was broad and encompassed several diffuse histologic subtypes in the Rappaport classification, the working formulation, and the classification of the Japanese lymphoma study group. However, differences in survival could not be correlated with differences in histologic subtype. All patients presented with Ann Arbor Stage IV lymphoma. Other common clinical features were generalized lymphadenopathy, hepatosplenomegaly, skin and peripheral blood involvement, hypercalcemia, and lytic bone lesions. The clinical course was aggressive with a median survival of 9 months. In two-third of patients with cutaneous involvement, epidermal infiltration resembling Pautrier microabscesses was observed. However, most cases can be readily distinguished from mycosis fungoides/Sézary syndrome on clinical and epidemiologic grounds. The presence of HTLV-antibodies in patients with lymphoid malignancies appears to define a distinct clinicopathologic syndrome which tends to occur in geographic clusters. Adult T-cell leukemia/lymphoma is favored as the diagnostic term for this clinicopathologic entity.