Lymphomatoid papulosis and Hodgkin's disease: are they related?

Initial Diagnosis of Classic Hodgkin Lymphoma With Skin Biopsy: A Rare Case and Review of Diagnostic Considerations

ABSTRACT

Classic Hodgkin lymphoma (CHL) is a B-cell-derived lymphoma that classically displays a bimodal age distribution. CHL typically involves the mediastinum, lymph nodes, and other visceral organs. CHL is characterized histologically by the presence of a relatively paucicellular neoplastic cell population composed of large atypical cells (including Hodgkin and Reed-Sternberg forms) in a reactive mixed inflammatory background, often with prominent necrosis. CHL rarely occurs in the skin, and the associated mixed inflammatory infiltrate or necrotic appearance can create diagnostic uncertainty. Herein, we report the case of a 31-year-old man presenting with a painful dendritic rash of the anterior chest wall with axillary lymphadenopathy. After multiple nondiagnostic biopsies that revealed largely necrotic material, a chest wall skin biopsy was obtained. The skin biopsy was diagnostic of CHL, based on the presence of large atypical dermal cells, including Hodgkin and Reed-Sternberg forms, which expressed CD15, CD30 and Fascin, in a typical mixed inflammatory and necrotic background. Through the lens of this case, we discuss the characteristics and mechanisms of skin involvement of CHL, and the histopathologic and immunohistochemical pitfalls when considering the rare diagnosis of CHL in the skin.

Localized lymphomatoid papulosis: Unilesional lymphomatoid papulosis, regional lymphomatoid papulosis, and persistent agmination of lymphomatoid papulosis

Lymphomatoid papulosis (LYP), the most common primary cutaneous CD30-positive lymphoproliferative disorder, is heralded by multiple papular and nodular lesions at anatomically discontiguous cutaneous sites. The histologic patterns are protean. An uncommon form of LYP is one that is anatomically confined. Cases of unilesional LYP, regional LYP, and persistent agmination of LYP were encountered in the routine and consultative practices of Weill Cornell Medicine, Division of Dermatopathology. The clinical presentation, outcomes, light microscopic findings, and phenotypic profile are reviewed. There were 10 cases of LYP presenting as solitary plaques or nodules primarily occurring in older patients and without a relevant medical history in most. Most cases occurred at an acral site with many localized to the foot; the morphology was one of a necrotizing angiocentric type E pattern and borderline type C morphology. Two of the unilesional patients in our series went on to develop mycosis fungoides, one at the initial site of unilesional type A LYP, and the other at a discontiguous site. Excluding one case, the solitary lesions underwent complete regression; after the lesions regressed, some cases had no apparent recurrence. The second anatomically confined variant of LYP in our series was regional LYP exhibiting a type E morphology in two cases and a hybrid type A and granulomatous eccrinotropic morphology in one case. There was no subsequent development of lymphoma, nor was there any spread to additional anatomic sites. The final category was persistent agmination of LYP, whereby the agminated papules of LYP were superimposed on a plaque of cutaneous T-cell lymphoma represented by mycosis fungoides in two and follicular helper T-cell lymphoma in one. In conclusion, anatomically confined LYP defines an uncommon form of LYP, but it is an important one to recognize because the histology can be worrisome despite an indolent clinical course. The clinical presentation, the infrequent association with lymphoma/leukemia, and histology are similar to conventional LYP, although there appears to be a greater tendency for complete regression without recurrence, excluding cases of persistent agmination of LYP whereby the clinical course warrants categorization as a form of cutaneous T cell lymphoma (CTCL).

Relapse of Hodgkin's disease revealed by skin involvement

We present a case of a relapse of HL revealed by a skin involvement. A biopsy of the skin lesion showed infiltration by a mixed cellularity and Reed–Sternberg cells. The immunoreactivity was positive for CD30 and CD15. The patient was undergoing ICE protocol with good improvement after three cycles.

Primary Cutaneous Hodgkin's Lymphoma: An Extremely Rare Entity

Skin involvement in Hodgkin's lymphoma (HL) is rare. The diagnosis can be difficult, mainly due to the wide range of cutaneous lesions that can be observed, but also due to the differential diagnosis, even after the immunohistochemical staining. We present the case of a 30-year-old man who presented with a painful cutaneous nodular lesion; biopsy and immunohistochemical stains were consistent with classic HL. The patient was treated with adriamycin, bleomycin, vinblastin, and dacarbazine (ABVD) with complete remission.

An Index Case of Cutaneous Hodgkin Lymphoma and Review of the Literature

Hodgkin lymphoma (HL), although a common hematopoietic malignancy, presents as a primary cutaneous form in extraordinarily rare instances. In this study, we present a remarkable case of a 76-year-old woman with a history of bony metastatic breast cancer who developed multiple subcutaneous nodules on the left neck and scalp. A biopsy revealed the histological and immunohistochemical findings of classic HL. She was treated with systemic chemotherapy and quickly achieved disease remission. Five months later, she was alive and without evidence of lymphoma, consistent with our understanding of primary cutaneous HL as an indolent variant of HL.

Abnormal activator protein 1 transcription factor expression in CD30-positive cutaneous large-cell lymphomas

BACKGROUND

CD30+ cutaneous large-cell lymphomas (CLCL) represent a heterogeneous subgroup of skin lymphomas including primary cutaneous CD30+ anaplastic large-cell lymphoma (C-ALCL), lymphomatoid papulosis (LyP), transformed mycosis fungoides (T-MF) and Hodgkin's lymphoma (HL) with cutaneous involvement. The activator protein 1 (AP-1) transcription factor consists of JUN, FOS and other protein families. Recent studies have revealed upregulation of JUNB in both MF and C-ALCL and overexpression of JUNB and CD30 in systemic HL and ALCL.

OBJECTIVES

To assess systematically the expression pattern of AP-1 transcription factors in CLCL.

METHODS

We analysed paraffin tissue sections from 27 patients with LyP, 10 with C-ALCL, eight with T-MF and two with cutaneous HL by immunohistochemistry with antibodies against c-JUN, JUNB, JUND, c-FOS and RAF-1. We also stained samples from 10 patients with C-ALCL, seven with Sézary syndrome (SS), six with T-MF, three with cutaneous HL, two with LyP and control samples with total and phosphorylated mitogen-activated protein kinase (MAPK) antibodies. Results Positive staining for JUND (++) was observed in 13 cases of LyP (48%), 10 C-ALCL, six T-MF (75%) and two cutaneous HL cases. Positive JUNB protein expression was present in four cases of T-MF (50%), four C-ALCL (44%), three LyP (11%) and two cutaneous HL. Expression of total (p44/42) MAP kinase and phosphorylated p44/42 MAP kinase were detected in nine cases of C-ALCL (90%), seven SS (88%), five T-MF (89%) and three cutaneous HL. Most of these samples also showed positive staining for JUNB.

CONCLUSION

These results suggest the presence of abnormal AP-1 protein expression in CLCL, which may be relevant to CLCL.

Primary and secondary cutaneous CD30+lymphoproliferative disorders: a report from the Dutch Cutaneous Lymphoma Group on the long-term follow-up data of 219 patients and guidelines for diagnosis and treatment

To evaluate our diagnostic and therapeutic guidelines, clinical and long-term follow-up data of 219 patients with primary or secondary cutaneous CD30+ lymphoproliferative disorders were evaluated. The study group included 118 patients with lymphomatoid papulosis (LyP; group 1), 79 patients with primary cutaneous CD30+ large T-cell lymphoma (LTCL; group 2), 11 patients with CD30+ LTCL and skin and regional lymph node involvement (group 3), and 11 patients with secondary cutaneous CD30+ LTCL (group 4). Patients with LyP often did not receive any specific treatment, whereas most patients with primary cutaneous CD30+ LTCL were treated with radiotherapy or excision. All patients with skin-limited disease from groups 1 and 2 who were treated with multiagent chemotherapy had 1 or more skin relapses. The calculated risk for systemic disease within 10 years of diagnosis was 4% for group 1, 16% for group 2, and 20% for group 3 (after initial therapy). Disease-related 5-year-survival rates were 100% (group 1), 96% (group 2), 91% (group 3), and 24% (group 4), respectively. The results confirm the favorable prognoses of these primary cutaneous CD30+ lymphoproliferative disorders and underscore that LyP and primary cutaneous CD30+ lymphomas are closely related conditions. They also indicate that CD30+ LTCL on the skin and in 1 draining lymph node station has a good prognosis similar to that for primary cutaneous CD30+ LTCL without concurrent lymph node involvement. Multiagent chemotherapy is only indicated for patients with full-blown or developing extracutaneous disease; it is never or rarely indicated for patients with skin-limited CD30+ lymphomas.

Primary and secondary cutaneous CD30+lymphoproliferative disorders: a report from the Dutch Cutaneous Lymphoma Group on the long-term follow-up data of 219 patients and guidelines for diagnosis and treatment

To evaluate our diagnostic and therapeutic guidelines, clinical and long-term follow-up data of 219 patients with primary or secondary cutaneous CD30+ lymphoproliferative disorders were evaluated. The study group included 118 patients with lymphomatoid papulosis (LyP; group 1), 79 patients with primary cutaneous CD30+ large T-cell lymphoma (LTCL; group 2), 11 patients with CD30+ LTCL and skin and regional lymph node involvement (group 3), and 11 patients with secondary cutaneous CD30+ LTCL (group 4). Patients with LyP often did not receive any specific treatment, whereas most patients with primary cutaneous CD30+ LTCL were treated with radiotherapy or excision. All patients with skin-limited disease from groups 1 and 2 who were treated with multiagent chemotherapy had 1 or more skin relapses. The calculated risk for systemic disease within 10 years of diagnosis was 4% for group 1, 16% for group 2, and 20% for group 3 (after initial therapy). Disease-related 5-year-survival rates were 100% (group 1), 96% (group 2), 91% (group 3), and 24% (group 4), respectively. The results confirm the favorable prognoses of these primary cutaneous CD30+ lymphoproliferative disorders and underscore that LyP and primary cutaneous CD30+ lymphomas are closely related conditions. They also indicate that CD30+ LTCL on the skin and in 1 draining lymph node station has a good prognosis similar to that for primary cutaneous CD30+ LTCL without concurrent lymph node involvement. Multiagent chemotherapy is only indicated for patients with full-blown or developing extracutaneous disease; it is never or rarely indicated for patients with skin-limited CD30+ lymphomas.

Regional lymphomatoid papulosis: a report of four cases

Lymphomatoid papulosis (LyP) is a chronic self-healing cutaneous eruption which is clinically benign but histologically malignant. Lesions occur episodically over the trunk and limbs. We describe four patients with regional LyP. All were male, with a range in age at onset from 12 to 47 years. In all cases, lesions were confined to a segmental unilateral area. Two patients had type A and two type B LyP. We have long-term follow-up on one patient whose lesions were limited to the right buttock for more than 20 years before more widespread lesions developed. Another patient with lesions on the left flank had mycosis fungoides limited to the same region. Only one other case of LyP presenting in a regional distribution has previously been described.

Lymphomatoid papulosis

Lymphomatoid papulosis is a chronic disease of cutaneous lymphoid infiltration characterized clinically by involuting and recurring papules, plaques, and nodules. The intriguing combination of a usually benign clinical course, a cytologically malignant lymphoid infiltrate on histologic examination, and a clear, but sporadic association with extracutaneous lymphomas has stimulated significant investigation. Application of recent technical advances to research in lymphomatoid papulosis prompts this review.

Epidemiology of lymphomatoid papulosis

BACKGROUND

Lymphomatoid papulosis is a rare skin disease with malignant potential. Its epidemiology is largely unknown.

METHODS

A case-control study of lymphomatoid papulosis was done to characterize the patient population and investigate the risk factors for its development. Fifty-seven patients with biopsy-proven lymphomatoid papulosis and 67 individually matched control subjects who were recruited among relatives and acquaintances of the patients answered a standard questionnaire over the telephone.

RESULTS

Among patients with lymphomatoid papulosis, 3 had a history of Hodgkin disease, 3 had non-Hodgkin lymphoma, and 10 had mycosis fungoides; none of the control subjects reported such histories. No significant differences were observed between patients and control subjects in regard to residence or travel history or exposures to various physical, chemical, and biologic agents. A higher, although not statistically significant, percentage of patients than control subjects reported a history of radiation therapy and nonlymphoid malignant lesions. No differences were found between patients and control subjects in regard to other medical conditions or family medical history.

CONCLUSIONS

Patients with lymphomatoid papulosis have a significantly increased frequency of prior or coexisting lymphoproliferative disorders, an increased frequency of nonlymphoid malignant lesions, and exposure to radiation therapy.

The prognosis of patients with lymphomatoid papulosis associated with malignant lymphomas

Lymphomatoid papulosis (LyP) is a disorder which generally runs a benign course, but can sometimes be associated with a malignant lymphoma. Information about the prognosis of these LyP-associated lymphomas is, however, fragmentary. In this study, the clinical data of 50 LyP-associated malignant lymphomas, including 11 patients of our own group and 39 reported in the literature, are evaluated. Three main groups of LyP-associated malignant lymphomas could be distinguished: cases associated with mycosis fungoides (19/50 cases). Hodgkin's disease (12/50 cases) and (CD30+) large-cell lymphomas (16/50). The results of this study demonstrate that patients with mycosis fungoides. Hodgkin's disease, and (CD30+) large-cell lymphomas limited to the skin have a favourable prognosis. However, the prognosis of patients developing a systemic (CD30+) large-cell lymphoma proved generally poor. The results of this study also indicate that the risk of an individual LyP patient developing systemic lymphoma is less than 5%.

A multidisciplinary approach to the diagnosis of cutaneous T-cell lymphomas

The cutaneous T-cell lymphomas (CTCLs) comprise a spectrum of non-Hodgkin lymphomas with a predilection for the skin. This heterogeneous group of CTCLs include the prototypic CTCL mycosis fungoides (MF) and the recently described Ki-1+ lymphomas. MF is notoriously difficult to diagnose in its early stages. The histologic appearance of early MF is indistinguishable from that of chronic dermatitis. The limitations of light microscopy in the diagnosis of the CTCLs have led to the development of other diagnostic laboratory techniques. The best approach to the diagnosis of the CTCLs is a multidisciplinary one and should include ultrastructural morphometry, immunophenotyping, immunogenotyping, and histologic evaluation whenever possible. It is the purpose of this overview to point out the strengths and weaknesses of each of these techniques and, together with clinical input, to provide a comprehensive and rational approach to patient care.

PUVA-induced lymphomatoid papulosis in a patient with mycosis fungoides

The occurrence of lymphomatoid papulosis in patients with cutaneous lymphoma, particularly mycosis fungoides, has been described in medical literature. A 68-year-old woman affected by mycosis fungoides in the plaque stage noticed that multiple papulonodular lesions of lymphomatoid papulosis developed suddenly after a few sessions of PUVA therapy. The PUVA induction of lymphomatoid papulosis was confirmed by the appearance of new lesions after a second cycle of PUVA exposure on a limited area of the body. Complete regression of all PUVA-induced lymphomatoid papulosis lesions was achieved within a few weeks with oral prednisone and topical steroids. During the entire treatment the patches and plaques of mycosis fungoides persisted unchanged.

Analysis of beta, gamma, and delta T-cell receptor genes in lymphomatoid papulosis: cellular basis of two distinct histologic subsets

To investigate the histogenesis of lymphomatoid papulosis (LYP), we have analyzed the configuration of the beta, gamma, and delta T-cell receptor (TCR) and Ig genes in DNA from 31 biopsies of 18 patients with this condition and also from peripheral blood mononuclear cells of eight of these patients. Immunoglobulin genes were in a germ-line configuration in all patients, and TCR genes were in a germ-line configuration in six patients. In nine patients, one or two rearranged bands (RB) were detected with both beta and gamma TCR probes and in one patient with beta, gamma, and delta TCR probes. Two patients, in whom beta and delta TCR genes were in a germline configuration, had evidence of multiple discrete rearrangements of gamma TCR genes, consistent with a polyclonal T-cell population. Analysis of multiple biopsies revealed that RB, when present, were identical in different lesions from individual patients. All but one of the peripheral blood samples showed a germ-line configuration. The exception had evidence of a rearrangement of gamma and delta in peripheral blood and a beta and gamma rearrangement within tissue. This study has established that only a proportion of patients with LYP have a monoclonal T-cell proliferation. Correlation with the clinicopathologic and immunophenotypic data revealed that a T-cell clone was limited to patients with Willemze type B LYP or "mixed type" LYP, whereas patients with type A LYP consistently showed a germline configuration of TCR genes. This study indicates that in LYP the atypical hyperchromatic cerebriform mononuclear cells of type B invariably constitute a monoclonal T-cell population whereas the atypical CD30 positive type A cells represent a proliferation of cells of non-B, non-T-cell lineage.

Hodgkin's disease followed by lymphomatoid papulosis. Immunophenotypic evidence for a close relationship between lymphomatoid papulosis and Hodgkin's disease

The clinical association of lymphomatoid papulosis and Hodgkin's disease and the striking morphologic similarity of atypical cells in lymphomatoid papulosis to Reed-Sternberg cells in Hodgkin's disease suggest that lymphomatoid papulosis and Hodgkin's disease are related. To test this possibility we studied the antigenic profile of Reed-Sternberg cells in the lymph nodes and of atypical cells in cutaneous lesions of lymphomatoid papulosis in two patients with Hodgkin's disease and lymphomatoid papulosis. In paraffin sections both cell types expressed CD30, CD45 T cell-restricted antigens, and occasionally CD15 antigens. They were negative for CD45 B cell-restricted antigens and for lysozyme. In cutaneous lymphomatoid papulosis lesions a similar immunologic profile of the atypical cells was found; that is, they were positive for CD30, CD2, CD3, and CD25 but negative for B cell and macrophage antigens. The similarity of the immunophenotype of Reed-Sternberg cells in lymph nodes affected by Hodgkin's disease and the immunophenotype of atypical cells of lymphomatoid papulosis lesions in the same patients suggests that the malignant cells in both conditions are derived from activated T cells and that they are closely related if not identical.

A case of lymphomatoid papulosis and Hodgkin's disease

Lymphomatoid papulosis is a unique paradoxic entity characterized by recurrent self-healing papulonodular lesions with histologic features of malignancy. Usually the disease has a protracted benign course; however, it can be associated with or evolve to a lymphoproliferative disorder. Thus "lymphoma-associated papulosis" represents the malignant end of a wide spectrum. We describe a case of a patient with lymphomatoid papulosis who developed Hodgkin's disease 8 years after the onset of skin lesions. Systemic chemotherapy achieved complete remission of Hodgkin's disease, but recurrent papulonodular lesions continued to form in the subsequent 18 months.

Long-term efficacy, curative potential, and carcinogenicity of topical mechlorethamine chemotherapy in cutaneous T cell lymphoma

Complete responses lasting from 4 to 14 years were documented in 65 of 331 (20%) patients with cutaneous T cell lymphoma treated with topical mechlorethamine (HN2) between 1968 and 1982. Such long-lasting remissions occurred most often, but not invariably, in patients with patch or plaque phase mycosis fungoides without palpable lymphadenopathy (stage Ia or Ib). The likelihood of a continuous remission was enhanced by initiation of treatment before an unequivocal pathologic diagnosis. Despite the long-lasting responses in these patients, however, relapses have been documented in 11 (17%) of these patients, and all relapses occurred within 8 years of discontinuing maintenance topical chemotherapy. Thus, in our experience, a continuous remission lasting 8 or more years provides evidence that cutaneous T cell lymphoma can be eradicated by aggressive topical chemotherapy. This circumstance was observed in 35 patients, representing a cure rate of at least 11% overall. In addition, when compared with the general population of the United States, patients who received topical HN2 were at an 8.6-fold and a 1.8-fold increased risk for the development of squamous cell carcinoma and enhanced for Hodgkin's disease and colon cancer but not for systemic cancers known to be induced by systemic administration of alkylating drugs. These results compare favorably with experiences with topical HN2 chemotherapy at other centers but raise questions about the risks associated with long-term administration for maintenance of remissions.

Lymphomatoid papulosis and its relationship to "idiopathic" hypereosinophilic syndrome

Persistent hypereosinophilia, endomyocardial fibrosis, and a recurrent self-healing papulonodular eruption with the histologic features of lymphomatoid papulosis are described in three patients. One patient died after developing an acute myeloblastic transformation in the eosinophil series. Immunocytochemical studies of cutaneous lesions in two of the patients suggested a mature T-cell phenotype with a predominant population of CD4-positive cells. Immunostaining of cutaneous tissue with monoclonal antibodies BE1 and BE2 yielded negative findings. Because it is now known from in vitro studies that T lymphocytes secrete the eosinopoietic factor, interleukin 5, it is possible that the cutaneous lesions, hypereosinophilia, and associated endomyocardial fibrosis were induced by transformed helper T lymphocytes in these three patients.

Histogenesis of Hodgkin's disease: possible insights from a comparison with lymphomatoid papulosis

Comparison of LyP and HD suggests that these are closely related lymphoproliferative disorders that may occur in the same patient, share similar histologic features, and have the same immunologic phenotype. Recent studies of the molecular biology of both disorders confirm a similar distribution of T-cell receptor gene rearrangement patterns. The study of LyP, although a rare and benign disorder, has improved our understanding of HD, which appears, in some cases, to be a proliferation of malignant activated T lymphocytes. Further analysis of LyP may lead to a better understanding of the spontaneous regression of this disorder and result in new methods for treatment of HD.

Lymphomatoid papulosis following Hodgkin's disease

Lymphomatoid papulosis has occurred in association with Hodgkin's disease. In all cases previously described, Hodgkin's disease has developed after, or concurrently with, the onset of lymphomatoid papulosis. Two patients who developed lymphomatoid papulosis 1 and 10 years after the diagnosis and therapy for advanced Hodgkin's disease are reported. The purpose of this report is to document this unusual sequence.

A histologic study of lymph nodes from patients with the Sézary syndrome

Lymph node sections from 12 patients with Sézary syndrome (SS) were studied histologically. The histopathologic alterations were compared with those in lymph nodes from four patients with (erythrodermatic) mycosis fungoides (MF) and two patients with a benign form of erythroderma. Most SS lymph nodes showed a rather monotonous and diffuse infiltration of cerebriform mononuclear cells (CMC), which tended to efface the normal lymph node architecture. By contrast, in lymph nodes involved by MF there was not only an increase in the number of CMC, but also a marked increase in the number of interdigitating reticulum cells that often showed a considerable degree of nuclear polymorphia. In the advanced stages of lymph node involvement by MF, blastic transformation was much more pronounced than in the SS lymph nodes. These histologic differences between MF and SS lymph nodes suggest that different pathogenetic mechanisms may be operative in the development of either of these conditions.

Common activated helper-T-cell origin for lymphomatoid papulosis, mycosis fungoides, and some types of Hodgkin's disease

A hypothesis is proposed to explain the nature of the Reed-Sternberg (RS) cell and the unexpectedly common clinical associations between lymphomatoid papulosis, mycosis fungoides, and some types of Hodgkin's disease. The RS cell appears to be a lymphoblast arising from activated helper T cells. In lymphomatoid papulosis, a cutaneous eruption with histological features of Hodgkin's disease, there is a spectrum of activated helper T cells, including cerebriform cells and large transformed RS-like cells. Clonal expansion of cerebriform cells in lymphomatoid papulosis leads to mycosis fungoides. Similar expansion of large transformed cells results in Hodgkin's disease. Progressive transformation of T4-positive cerebriform cells to Ki-1-positive RS cells accounts for rare cases of coexistent mycosis fungoides and Hodgkin's disease. Confirmation of this hypothesis should focus attention on the family of human T-cell leukaemia/lymphoma viruses as possible aetiological agents in these helper-T-cell disorders.

Clinical and histologic differentiation between lymphomatoid papulosis and pityriasis lichenoides

The relationship between lymphomatoid papulosis and pityriasis lichenoides is a matter of considerable debate. Differentiation between these two conditions is, however, important because patients with lymphomatoid papulosis, unlike those with pityriasis lichenoides, may develop systemic lymphoma and thus require long-term follow-up. In our study the clinical and histologic features of eighty-two patients with pityriasis lichenoides and twenty-six patients with lymphomatoid papulosis were reviewed and compared. Clinical and histologic differences were recognized, not only allowing differentiation between the two conditions, but also suggesting that they are pathogenetically distinct diseases. Finally, evidence is presented to suggest that the different views on the relationship between these diseases mainly result from differences in patient selection.

Hodgkin's disease: five steps from autoimmunity to cancer

A five-step hypothesis on the pathogenesis of Hodgkin's disease (HD) is presented. Weak immune suppressor activity gives a predisposition for the development of the disease, after which a non-specific immune stimulation can initiate a self-perpetuating uncontrolled stimulation between interdigitating cells (IDCs), macrophages and helper T lymphocytes (TH). The disease spreads to other lymph nodes through the secretion of humoral factors and by migration of cells. The response of the suppressor branch of the immune system is delayed, and comes from areas not yet involved in the disease, primarily from the spleen and bone marrow. Treatment will result in the predominance of the suppressor activity and allow calming of the disease. In a terminal phase, a possible neoplastic transformation of the chronically stimulated immune cells may give rise to frequent extranodal localizations and a rapid progression of the disease.