Cytogenetic abnormalities in natural killer cell lymphoma/leukaemia--is there a consistent pattern?

The group of putative natural killer cell lymphomas, also known as NK/T cell lymphomas (nasal and nasal-type) has been characterized only in recent years. Whilst a good amount of clinical information has been gathered on this group of uncommon lymphoid neoplasms, there is little information on the cytogenetic or molecular alterations. A review of the literature shows that chromosomal abnormalities are indeed commonly found in these tumours, and aberrations involving chromosome 6q are most frequent. Other non-random abnormalities include +X, i(1q), i(7q), +8, del(13q), del(17p), i(17q), and 11q23 rearrangement. It appears that deletions of the chromosome 6 at around q21-23 region is the commonest recurrent chromosomal abnormality, and fluorescence in situ hybridisation studies have confirmed the occurrence of deletions at 6q22-23 in the CD3- CD56+ tumour cells. Search for the involved genes located in this chromosome region can potentially shed light on the molecular pathogenesis of the natural killer cell neoplasms.

Pulmonary sequestration diagnosed by contrast enhanced three-dimensional MR angiography

Pulmonary sequestration is a congenital bronchopulmonary foregut malformation in which a segment of lung parenchyma is not connected to the tracheobronchial tree. This abnormal segment receives a blood supply from the systemic circulation. Multiple imaging modalities have been used to demonstrate the vascular anatomy of the sequestration. Different magnetic resonance angiography (MRA) techniques have been employed in the identification of these anomalous vessels. We report a case of pulmonary sequestration diagnosed by MRI with the use of contrast enhanced three-dimensional MRA.

T-cell prolymphocytic leukemia with a novel translocation (6;11)(q21;q23)

T-cell prolymphocytic leukemia (T-PLL) is an uncommon chronic lymphoproliferative disorder characterized by lymphadenopathy, splenomegaly, and lymphocytosis. The leukemic cells have the appearance of prolymphocytes and usually an immunophenotype of T-helper cells (CD3+ CD4+ CD8-). Inv(14q), del(11q), i(8q), and rearranged Xq28 are the commonest nonrandom chromosomal abnormalities in T-PLL. Recently, it has been shown that the ataxia-telangiectasia mutated (ATM) gene located at 11q23 is often deleted in T-PLL, suggesting a tumor suppressor role of the ATM gene on tumorigenesis of T-PLL. We report a case of T-PLL with t(6;11)(q21;q23) as the sole chromosomal abnormality and suggest that the cytogenetically identified translocation also implicates the ATM gene.

Cytogenetic abnormalities in chronic B-cell lymphoproliferative disorders in Chinese patients

We analyzed the cytogenetic findings of 59 Chinese patients with chronic B-cell lymphoproliferative disorders. More than half of the patients (n = 36, 61%) had chronic lymphocytic leukemia. Cytogenetic abnormalities were demonstrated in 44.1% (26/59) of the patients. Trisomy 12 was the most frequent abnormality in chronic lymphocytic leukemia and was found in 27.8% (10/36) of the patients, indicating that the incidence of trisomy 12 in chronic lymphocytic leukemia in Chinese patients might not be low compared with the West as previously suggested. Structural abnormalities involving chromosomes 13 at band q14 were the next most common abnormalities in patients with chronic lymphocytic leukemia. Among the 11 patients with mantle cell lymphoma in leukemic phase, t(11;14) was seen in only 2 patients (18.2%). Several unusual cytogenetic abnormalities also were found.

Linker for activation of T cells (LAT), a novel immunohistochemical marker for T cells, NK cells, mast cells, and megakaryocytes: evaluation in normal and pathological conditions

LAT (linker for activation of T cells) is an integral membrane protein of 36-38 kd that plays an important role in T cell activation. Using a rabbit polyclonal antibody generated against the cytosolic portion of LAT, we investigated the immunohistochemical expression of LAT in normal and pathological hematolymphoid tissues. LAT reacts with human T cells in paraffin sections, including decalcified bone marrow trephines. LAT appears early in T cells at the thymocyte stage and before TdT expression in embryos, and is expressed in peripheral lymphoid tissues, without restriction to any T cell subpopulations. In addition to T cells, natural killer (NK) cells (evaluated with flow cytometry), megakaryocytes and mast cells are also LAT-positive, whereas B cells and other myeloid and monocytic derived cells are negative. Tested on a total of 264 paraffin-embedded tissue biopsies, LAT reacted with the great majority (96.8%) of T/NK-cell neoplasms, covering the full range of T cell maturation. Although antibodies to both LAT and CD3 had a similarly high sensitivity in the staining of T/NK-cell lymphomas, when used in conjunction, they successfully identified a higher number of cases (98.4%). Atypical megakaryocytes from different hematological disorders, as well as mast cells in mastocytosis were also LAT-positive, but all neoplasms of B cell origin, Hodgkin's lymphomas, and several nonlymphoid malignancies were negative. These data indicate that the anti-LAT antibody may be of value to diagnostic histopathologists for the identification of T cell neoplasms.

Dedifferentiation in adenoid cystic carcinoma of salivary gland: an uncommon complication associated with an accelerated clinical course

Adenoid cystic carcinoma (ACC) of the salivary gland is generally an indolent tumor that pursues a protracted clinical course with recurrences and late metastasis. The authors report three cases of ACC with dedifferentiation to high-grade malignant neoplasms. One patient developed dedifferentiated ACC ab initio, with extensive local disease and multiple lymph nodes metastases at first presentation, requiring mutilating surgery. Two patients had dedifferentiated ACC 4 and 10 years, respectively, following excision of the initial uncomplicated ACC; both patients died within 1.5 years after recurrence. Histologically, the dedifferentiated component appeared as a distinct population of anaplastic cells with more abundant cytoplasm, irregular-shaped tumor islands infiltrating a desmoplastic stroma, and total loss of bicellular differentiation characteristic of ACC. The immunophenotypic profile was altered in comparison with the ACC, such as acquisition of strong staining for S100 protein and lack of a myoepithelial component in the two cases that were interpreted as being poorly differentiated adenocarcinoma. One case was a sarcomatoid neoplasm with focal myoepithelial features. Overexpression of p53 protein was demonstrated in the dedifferentiated component in one case, and overexpression of cyclin D1 was seen in two cases. The dedifferentiated component had a higher Ki67 index than did the ACC. To the authors' best knowledge, this report represents the first documentation of dedifferentiation as a form of tumor progression in ACC, which is associated with a sinister clinical outcome.

Cribriform-morular variant of papillary carcinoma: a distinctive variant representing the sporadic counterpart of familial adenomatous polyposis-associated thyroid carcinoma?

We describe herein four cases of an unusual sporadic thyroid tumor that shares the morphologic features of a distinctive follicular cell neoplasm previously proposed as a feasible indicator of familial adenomatous polyposis. We also review five other similar cases reported in the literature. All of the nine patients were young women, aged 16 to 30 years. Grossly, the neoplasms measured 1.5 to 5.6 cm; they were solid and solitary, except one case, which showed two tumor nodules, one in each lobe. Histologically, the lesions were encapsulated, and they exhibited an intricate blending of cribriform, follicular, papillary, trabecular, and solid patterns of growth, with morular (squamoid) areas. Cribriform structures were prominent, being formed by anastomosing bars and arches of cells in the absence of intervening fibrovascular stroma. Follicular areas were usually devoid of colloid, and the papillae were lined by columnar cells. There were focal areas of trabecular arrangement reminiscent of hyalinizing trabecular adenoma. The tumor cells were cuboidal or tall, with frequent nuclear pseudostratification and abundant eosinophilic-to-oxyphilic cytoplasm. The nuclei were usually hyperchromatic, but nuclear grooves, pale or clear nuclei, and intranuclear cytoplasmic inclusions were variably present. Morules with peculiar nuclear clearing caused by biotin accumulation were scattered in the tumors. Vascular and/or capsular invasion were noted in all of the cases except one, and lymph node metastasis was found in two cases. Immunohistochemical stains showed reactivity for thyroglobulin, epithelial membrane antigen, cytokeratins (including 34betaE12), vimentin, estrogen and progesterone receptors, bcl-2, and Rb proteins. Follow-up in seven cases showed that all of the patients were alive with no evidence of disease at 1 to 13 years after diagnosis. Thus, the behavior of this variant seems to be similar to that of conventional papillary carcinoma Because of the distinctive histologic features, we propose naming this tumor the cribriform-morular variant of papillary carcinoma.

Primary juxtaarticular soft tissue lymphoma arising in the vicinity of inflamed joints in patients with rheumatoid arthritis

AIMS

Primary soft tissue lymphoma is uncommon and little is known regarding its aetiology and pathogenesis. In a review of 37 soft tissue lymphomas we uncovered three cases associated with rheumatoid arthritis which we report herein.

METHODS AND RESULTS

The clinical records and pathology of the cases are described together with the results of in situ hybridization studies with oligonucleotide probes to Epstein-Barr virus (EBV) encoded RNA (EBER). All three patients were females with a long-standing history of rheumatoid arthritis ranging from 9 to 17 years. Each presented with a soft tissue mass in the vicinity of a joint affected by rheumatoid disease. All had received prior treatment with nonsteroidal anti-inflammatory drugs and one also received gold, penicillamine and intra-articular steroids to affected joints. None had received methotrexate. Histologically, the juxtaarticular soft tissue masses were all B-cell lymphomas. None were associated with EBV as determined by in situ hybridization.

CONCLUSIONS

These cases document an association between rheumatoid arthritis and soft tissue lymphoma of B-cell type, arising in the vicinity of an affected joint. Chronic local immune stimulation may have played a significant role in the genesis of these lymphomas, unlike the frequently reversible and EBV-positive lymphomas that occur in rheumatoid patients on immunosuppressive therapy.

Immunostaining for cyclin D1 and the diagnosis of mantle cell lymphoma: is there a reliable method?

Immunostaining for cyclin D1 has become essential for the reliable diagnosis of mantle cell lymphoma (MCL). MCL is associated with a poor prognosis and its distinction from other small B-cell lymphomas is clinically important. However, many diagnostic laboratories report problems in finding a reliable method. The following articles by Chan and by Miller, Munson & Isaacson discuss the common problems and describe successful methods with advice on diagnostic interpretation.

Peripheral T-cell and NK-cell neoplasms: an integrated approach to diagnosis

Peripheral T-cell and NK-cell neoplasms account for only 10% of all non-Hodgkin's lymphomas, but they commonly pose great difficulties in diagnosis and classification. This article addresses the distinction between peripheral T-cell or NK-cell lymphoma and reactive lymphoid hyperplasia, the importance of recognition of the T-cell or NK-cell lineage for a lymphoma; and the importance of classification of a peripheral T- or NK-cell lymphoma. To solve these problems, it is imperative to adopt an integrated approach, taking the clinical features, morphologic findings, immunohistochemical profile, and/or genetic data into consideration.

Applicability of living donor liver transplantation to high-urgency patients

BACKGROUND

Cadaveric liver donors are scarce in Hong Kong, and the application of liver transplantation to high-urgency patients is limited. We evaluated the use of grafts from living donors in this setting.

METHODS

From July 1994 to January 1998, 49 consecutive adult patients who were intensive care unit-bound because of acute or chronic liver failure were put on a high-urgency list for liver transplantation. Family members were not solicited for living donation, and the initiation and decision for living donor liver transplantation (LDLT) was based on the donor's voluntary intent. Assessment of the living donor, including blood tests, computed tomographic volumetry, and angiography, was performed only after informed consent was executed.

RESULTS

In 25 of 49 (51%) patients, no family member volunteered as living donor; 23 died awaiting donor organs, and 2 received a cadaveric graft. Twenty-four (49%) patients had 36 family members who volunteered as living donors. Before evaluation of living donor was completed, two patients received a cadaveric liver transplant. LDLT was not performed in nine patients because of recipient contraindications (n=4), ABO blood group incompatibility (n=3), and withdrawal of donor (n=2). Eight of these nine patients died, and one received a cadaveric liver graft. The remaining 13 (27%) patients received grafts from living donors. Four of 5 (80%) patients who underwent cadaveric liver transplantation and 11 of 13 (85%) who underwent LDLT survived. Thus, emergency transplantation from living donors increased the applicability of liver transplantation from 10% to 37%, and the survival rate after emergency LDLT (85%) was superior to that of the remaining patients (11%).

CONCLUSIONS

When cadaveric organ donation is scarce, emergency liver transplantation from living donors can be applied to high-urgency adult patients.

Peripheral T and putative natural killer cell lymphomas commonly coexpress CD95 and CD95 ligand

The CD95 (Fas)/CD95 ligand (CD95L) system is an important mechanism triggering apoptosis, and CD95L expression has recently been implicated for immune evasion and aggressive behavior in malignancies. This study aimed to investigate CD95 and CD95L expression in lymphomas and the possible relationship with tumor cell apoptosis, with emphasis on the natural killer (NK) cell lymphomas, which are highly aggressive neoplasms and frequently exhibit tumor cell apoptosis/necrosis. Frozen sections of 82 cases of lymphomas obtained from Queen Elizabeth Hospital and Caritas Medical Center, Hong Kong, were immunostained with polyclonal anti-CD95 and anti-CD95L antibodies. The NK-cell lymphomas were also studied for apoptosis by in situ end labeling (ISEL) method, and zonal tumor cell death was evaluated semiquantitatively. The cases studied included 27 NK-, 22 T-, and 33 B-cell lymphomas. CD95 was expressed in 25 (93%) NK-, 11 (50%) T-, and 14 (42%) B-cell lymphomas. CD95L was expressed in 19 (70%) NK-, 15 (68%) T-, and 3 (9%) B-cell lymphomas. There was significant difference in the frequency of CD95 expression between B- and NK- (P < .001), and between T- and NK-cell lymphomas (P < .05), and in CD95L expression between B- and T- (P < .01) or NK-cell (P < .01) lymphomas. Zonal tumor cell death was present in 21 (78%) NK-cell lymphomas and 1 (4.5%) T-cell lymphoma and showed no correlation with CD95 or CD95L expression. ISEL analysis showed apoptosis predominantly in the viable areas in only 5 (24%) NK-cell lymphomas. In conclusion, CD95L is frequently expressed in NK- and T-cell lymphomas, but rarely in B-cell lymphomas. Zonal tumor cell death is not correlated with CD95 or CD95L expression and thus the CD95/CD95L system probably does not contribute significantly to this phenomenon. We postulate that the frequent expression of CD95L by NK- and T-cell lymphomas may mediate local or systemic tissue damage and immune evasion, and may contribute to the clinical aggressiveness of these tumors.

Mesenchymal tumors of the gastrointestinal tract: a paradise for acronyms (STUMP, GIST, GANT, and now GIPACT), implication of c-kit in genesis, and yet another of the many emerging roles of the interstitial cell of Cajal in the pathogenesis of gastrointestinal diseases?

This commentary addresses the nature of interstitial cells of Cajal (which can now be conveniently demonstrated by immunostaining for c-kit) and their possible role in the genesis of various motility disorders of the gastrointestinal tract. The evolution of the concept on the nature of gastrointestinal stromal tumors is discussed, with emphasis on the recent finding of a very high frequency of c-kit immunoreactivity in these tumors, suggesting that they might exhibit differentiation toward interstitial cells of Cajal. The practical immunohistochemical applications of antibodies to c-kit in diagnostic pathology are also discussed.

Thymic carcinoma arising in thymoma is associated with alterations in immunohistochemical profile

Thymic carcinoma is an uncommon tumor. Most cases appear to arise de novo, but in rare instances they can arise in thymomas. We report the clinicopathologic features and immunohistochemical profile of five cases of thymic carcinoma accompanied by a component of thymoma. Immunohistochemical studies were performed with the avidin-biotin-peroxidase complex method using monoclonal antibodies to p53(DO7), CD99(O13), epithelial membrane antigen, CD5(NCL-CD5-4C7), vimentin (V9), and cytokeratins 7, 8, 18, and 19. The patients consisted of three men and two women with a median age of 57 years. One patient had myasthenia gravis, and the other four presented with chest symptoms. One patient had concurrent adenocarcinoma of the lung with metastasis. Four of the patients died within 15 months. The thymomas consisted of two large polygonal cell thymomas, two squamoid thymomas, and one spindle cell thymoma. The malignant components included two undifferentiated carcinomas, one spindle cell carcinoma, one squamous cell carcinoma, and one clear cell carcinoma with squamous differentiation. There was no correlation between the histologic types of the thymoma and the thymic carcinoma. In three cases, excluding the two squamoid thymomas, the thymic carcinomas occurred in the necrotic areas of the thymoma. They showed upregulated expression of epithelial membrane antigen and cytokeratins 7, 8, 18, and 19, similar to the so-called "interface phenomenon" described in the invasion front of other types of carcinoma. Increased p53 protein expression was observed in all five carcinomas, and there was loss of CD99+ immature T lymphocytes. Among the thymic carcinomas, only the squamous component of the clear-cell carcinoma stained for CD5, a marker commonly expressed in thymic carcinomas. Paradoxically, a squamoid thymoma, but not its associated spindle cell carcinoma, expressed CD5, suggesting the acquisition of an "aggressive" phenotype by the squamoid thymoma, but with loss of the marker on malignant transformation. One undifferentiated carcinoma acquired vimentin immunoreactivity, whereas four other carcinomas and all five thymomas were negative. In conclusion, thymic carcinoma can arise in any histologic type of thymoma, including spindle cell thymoma, which is generally regarded as a benign neoplasm. The prognosis appears to be poor. Tumor necrosis in a thymoma should alert the pathologist to search for malignant change. The malignant change is commonly associated with increased expression of epithelial membrane antigen, cytokeratin subtypes, or p53 protein, and loss of CD99+ immature T lymphocytes, and is occasionally associated with a change in the expression of CD5 or vimentin.

Prognostic significance of DNA flow cytometric analysis in patients with nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a prevalent malignant tumor among Southern Chinese. Previously, the authors described the prognostic significance of a serum antibody assay to a recombinant Epstein-Barr virus Bam HI-Z replication activator protein (ZEBRA) in NPC patients with long term follow-up. In this study, the authors further reported the use of DNA flow cytometry (DNA-FCM) as an additional technique for determining the prognosis of NPC patients in the same series.

METHODS

One hundred and forty-three archival biopsies from 110 NPC patients were deparaffinized and subjected to DNA-FCM analysis. DNA ploidy state and various proliferative indices (PI) of the tumors were correlated with patient survival and frequency of recurrence.

RESULTS

Among the biopsies analyzed, 119 were histologically positive NPC and 24 were negative. Fifty-one tumor biopsies that fulfilled the guideline criteria of the DNA Cytometry Consensus Conference were correlated with the clinical manifestations of the patients. Among them, 43 tumors (84%) were DNA diploid and 8 (16%) were aneuploid. Two PI, S-phase fraction (SPF) and proliferation fraction (PF), appear to be potentially useful prognostic indicators. For example, PF in patients who developed locoregional recurrence (15.1%) and distant recurrence (16.4%) after radiation therapy both were significantly higher than PF in patients who were in complete remission (8.2%) (P = 0.0005 and P = 0.004, respectively). Significant differences in SPF between patients with distant recurrence (10.6%) and those in remission (5.7%) also was found (P = 0.005). Using Kaplan-Meier analysis, patients with high PF, high SPF, and aneuploid tumors had significantly poorer 12-year survival rates (35%, 26%, and 28%, respectively) than those patients with low PF, low SPF, and diploid tumors (77%, 67%, and 59%, respectively) (P < 0.0009, P < 0.004, and P < 0.01, respectively).

CONCLUSIONS

Determination of tumor PI and DNA ploidy state by DNA-FCM at diagnosis of NPC can be potentially useful in selecting a poor prognostic subgroup of NPC patients. These parameters may enable oncologists to plan for more stringent treatment strategies such as hyperfractionated and accelerated radiation therapy or concomitant chemoradiotherapy for these patients.

Virtual intraluminal endoscopy: a new method for evaluation and management of choledochal cyst

A 12-year-old girl who suffered from cholangitis was treated successfully with appropriate antibiotics. She had undergone an operation in mainland China, the exact nature of which was unknown. After an ultrasound study, she underwent a helical computed tomography (CT) cholangiogram using intravenous meglumine iodoxamine. The volume data were transferred to a workstation and virtual endoscopy rendering reconstruction of bile ducts was performed. Findings of this study showed that she had cyst excision with hepaticojejunostomy (HJ), and her intrahepatic ducts were packed with stones. Virtual endoscopy gave the impression that the examiner was flying inside the lumen and showed the stricture at the HJ anastomosis, the inner surface of the bile ducts, areas of dilated intrahepatic ducts, and the intrahepatic stones. The study overcame the need for an invasive study such as a percutaneous transhepatic cholangiography (PTC) and also facilitated appropriate surgical treatment in a timely fashion. It is believed that virtual intraluminal endoscopy (VIE) is helpful in the evaluation and management of selected cases of choledochal cyst.

Angiosarcoma of the ovary: clinicopathologic and immunohistochemical analysis of four cases with a broad morphologic spectrum

Angiosarcoma most frequently occurs in the skin of the head and neck region of elderly persons, lymphedematous limbs, or in deep soft tissue but only rarely has been described to occur in the female genital tract. Four cases of angiosarcoma of the ovary are described herein. They occurred in patients 25 to 42 years old (median, 31 years). The most common clinical presentation was abdominal pain. All of the tumors were unilateral, hemorrhagic, and ranged from 3.5 cm to 14 cm (median, 13 cm). The histologic appearance of the tumors was varied, and often the vascular nature of the tumor was not apparent immediately. Some of the tumors had a fascicular growth pattern composed of spindle-shaped cells with ovoid nuclei and ample eosinophilic cytoplasm closely mimicking leiomyosarcoma. Other tumors resembled ovarian yolk sac tumor with a reticular growth pattern, whereas, in other areas, cystic structures lined by hobnailed hyperchromatic enlarged nuclei simulated clear cell carcinoma of the ovary. Despite these misleading morphologic findings, all cases were characterized, at least focally, by vasoformative channels or discrete cytoplasmic vacuoles, and all were immunoreactive for vascular markers. Two patients with spread of tumor outside of the ovary died 1 month and 2 years after initial diagnosis, respectively. Two patients with tumor confined to the ovary are alive without evidence of disease 3 and 14 months after diagnosis, respectively. The differential diagnosis of this unusual neoplasm is discussed, and the literature is reviewed.

Drug use concomitant with cyclosporine immunosuppressive therapy for 3 years after renal transplantation

Little is known about outpatient drug use concomitant with cyclosporine immunosuppressive therapy following renal transplantation. In part, this stems from the difficulty in monitoring drugs not covered by Medicare. Using several linked state and federal program data bases, a cohort of dually eligible Medicare/Medicaid California residents aged > or = 18 years with a first cadaver transplant in 1988 was followed for 3 years to examine drug use and medical expenditures: 99, 122, and 90 patients met these inclusion criteria in each study year, respectively. More than one third of the study population received one or more drugs that inhibit metabolism and increase cyclosporine circulating blood levels (class I) in each year posttransplant. The most commonly prescribed were diltiazem, verapamil, metoclopramide, and ketoconazole. Patients receiving class I drugs had a lower mean cyclosporine dose compared with those not receiving such drugs in all three study years, suggesting that overall cost savings were obtained among patients using class I drugs. Less than one tenth of the study population in any given year received a drug that induces metabolism and decreases cyclosporine blood levels (class II), the most common of which was phenytoin. Use of nephrotoxic drugs (eg, trimethoprim-sulfamethoxazole, gentamicin, and tobramycin) that exhibit nephrotoxic synergy when used with cyclosporine was common. Almost half of all posttransplant patients were prescribed a nephrotoxic drug during the study period. Pharmaceuticals (primarily cyclosporine) accounted for 35% to 43% of the approximately $17,000 to $19,500 per patient annual health care expenditures incurred in the first 3 years following kidney transplantation.

Primary non-Hodgkin's lymphoma of the nose and nasopharynx: clinical features, tumor immunophenotype, and treatment outcome in 113 patients

PURPOSE

To study the clinical features and outcome for primary non-Hodgkin's lymphomas of the nose/nasopharynx (NNP-NHLs) according to immunophenotype.

PATIENTS AND METHODS

One hundred thirteen Chinese patients with primary NNP-NHLs that belonged to the categories E, F, G, or H according to the Working Formulation (WF), with full immunophenotypic data and complete clinical follow-up data, were analyzed in this retrospective study.

RESULTS

Ninety (79.6%) patients had localized (stage I or II) disease, while 23 (20.4%) had stage III or IV disease. The lymphomas in 51 (45.1%), 24 (21.3%), and 38 (33.6%) patients showed natural killer (NK)/T- (CD56-positive), T-cell, and B-cell immunophenotype, respectively. Seventy-three patients (65.8%) achieved a complete remission, of whom 34 (46.6%) subsequently relapsed. The median follow-up time for those alive was 88 months. The 5-year actuarial disease-free and overall survival rates were 34.4% and 37.9%, respectively. Multivariate analysis showed that only stage and immunophenotype were significant for survival. NK/T lymphomas were distinctive among the three immunophenotypes in the following aspects: the highest male-to-female ratio, more frequent involvement of the nasal cavity alone, higher risk of dissemination to the skin, more frequent development of hemophagocytic syndrome, and the worst prognosis (overall median survival, 12.5 months).

CONCLUSION

The three immunophenotypes studied are shown to exhibit different clinical patterns. Since the NK/T phenotype carries the worst prognosis, patients who present with NNP-NHL should have their tumors analyzed for CD56 expression.