Can mycosis fungoides begin in the epidermis? A hypothesis

Post-Inflammatory Hypopigmentation: Review of the Etiology, Clinical Manifestations, and Treatment Options

Post-inflammatory hypopigmentation is a common acquired pigmentary disorder that is more prominent in skin of color, leading to great cosmetic and psychosocial implications. Often, a diagnosis with a pigmentary disorder can negatively impact an individual's health-related quality of life and may result in stigma. Although most cases of post-inflammatory hypopigmentation resolve spontaneously over time, a systematic diagnostic approach can help with identifying the underlying etiology and informing treatment strategies. It can be due to cutaneous inflammation, sequelae of inflammatory or infectious dermatoses, or dermatologic procedures. Therefore, a thorough understanding of the epidemiology, patient history, physical exam findings, and clinical features of post-inflammatory hypopigmentation phenomenon can explain the primary cause to providers and allow for patient education. It is also important to understand the various therapeutic approaches available and the efficacy of these options, which will inform providers to choose the appropriate therapy for patients. Although algorithms exist for classifying acquired disorders of hypopigmentation, there are no established algorithms for the diagnosis and treatment of post-inflammatory hypopigmentation, which warrants further exploration and discourse.

Hypopigmented Mycosis Fungoides Mimicking Vitiligo

ABSTRACT

Hypopigmented mycosis fungoides (HMF) is a clinical variant of MF with a presentation similar to other hypopigmented diseases, especially vitiligo. In this article, we report an adult case of HMF mimicking vitiligo. A 53-year-old man presented with an asymptomatic well-defined focal and hypopigmented patch with erythematous to brownish macules on the flank which had been developing over several months without other cutaneous findings. He had no past medical or trauma history. Skin biopsy from the hypopigmented patch indicated a slightly band-like, superficial dermal infiltrate of lymphocytes with mild cytologic atypia and epidermotropism. Fontana-Masson and Mart-1 stains showed a decrease in the epidermal pigment and the number of basal melanocytes. In addition, CD4 and CD8 stains were positive, predominantly the CD8 stain, and loss of CD7 stain was noted in the epidermal atypical lymphocytes. A T-cell receptor gene rearrangement study from the hyperpigmented area showed monoclonality. Finally, we diagnosed the patient with HMF. After about 17 months of treatment with narrow-band ultraviolet B, the hypopigmented lesion had notably improved in both the clinical and histological aspects. The clinical appearance of our case was similar to vitiligo while clinical improvement was also exceptionally similar to the skin findings from follicular repigmentation after narrow-band ultraviolet B treatment in vitiligo. Therefore, dermatologists should consider the clinical differential diagnosis of HMF in patients with an asymptomatic hypopigmentation, especially in dark-skinned Asian patients.

The Differential Diagnosis of Hypopigmented Mycosis Fungoides and Vitiligo With Reflectance Confocal Microscopy: A Preliminary Study

Objective: To investigate the role of reflectance confocal microscopy (RCM) in the differential diagnosis of hypopigmented mycosis fungoides (HMF) and vitiligo.

Methods: Cases with persistent hypopigmented patches, suspicious of early stage vitiligo, or HMF were imaged with RCM. The melanin contents and inflammatory conditions of the epidermis and superficial dermis of the lesions were compared with the same layers of the adjacent skin, and then, the imaged lesions were biopsied and analyzed by histology.

Results: 15 cases were enrolled in this study, and based on the RCM findings, there was just slight or moderate reduction of melanin but no melanin absence in the basal cell layer of HMF lesions. The finding of monomorphous weakly refractile, oval to round cells on the basis of vesicle-like dark space was clearly elucidated in the epidermis of the lesions by RCM, which indicates the Pautrier's microabscesses on histopathology. Among those 15 cases, 13 cases were identified as HMF, and the other two cases were vitiligo, based on RCM findings, which were confirmed by histology analysis.

Conclusions: The RCM findings correlated well with histology results in the screening of HMF, which indicates the RCM is an important tool in the early detection and differential diagnosis of HMF.

Hypopigmented Mycosis Fungoides: A Clinical and Histopathology Analysis in 9 Children

BACKGROUND

Hypopigmented mycosis fungoides (HMF) is an uncommon variant of mycosis fungoides.

AIMS

To study the clinical and histopathology presentation in children with HMF.

METHOD

We reviewed 9 children diagnosed with HMF. The clinical data were collected and analyzed.

RESULT

Eight boys and 1 girl were included, with a median onset age of 7.4 year old and median age of diagnosis of 10.5 year old. Multiple hypopigmented patches were observed in all patients, and 5 patients exhibited multiple scaly erythema at the center of hypopigmented patches. Histopathology showed atypical lymphocytes with hyperchromatic, irregular, and cerebriform nuclei, infiltrated in the epidermis and dermis. Pautrier's microabscesses was noted in 6 of 9 patients, and papillary dermal fibroplasia was noted in 6 of 9 patients. CD8 predominance was detected in 4 of 6 patients. Four patients were simultaneously subjected to skin biopsy on hypopigmented patches and scaly erythema simultaneously. Compared with hypopigmented specimens, erythema biopsy detected deeper and denser infiltration of atypical lymphoid cells in 3 of 4 patients, higher CD4+/CD8+ ratio in 4 of 4 patients, more CD5 loss in 2 of 4 patients, and more CD7 loss in 2 of 4 patients. TCR gene monoclonal rearrangement was detected in 2 of 5 patients. Narrowband ultraviolet B phototherapy was applied in 7 patients. One of 7 patients achieved complete response, and 6 of 7 patients achieved partial response. No recurrence was noted with the median follow-up period of 6 months.

CONCLUSION

HMF could occur in young patients, with indolent and benign course. HMF could gradually seem as scaly erythema based on hypopigmented patches. The histopathology indicated a more advanced stage of the scaly erythema lesions than hypopigmented patches.

Comparison between the histopathological and immunophenotypical features of hypopigmented and nonhypopigmented mycosis fungoides: A retrospective study

BACKGROUND

Mycosis fungoides (MF), the commonest primary cutaneous T-cell lymphoma, has classic and variant types which include hypopigmented MF (HMF). Previous studies have identified distinct clinicopathological profiles in HMF. This study aims to objectively compare the clinicopathological features of HMF with non-HMF lesions in order to characterize salient features of HMF.

METHODS

This cross-sectional, retrospective study analyzed biopsy specimens of 87 patients with MF. HMF and non-HMF groups were compared using clinical data, immunophenotypic features and scores given for six histopathological features: dermal infiltrate, basilar and superficially extending epidermotropism, Pautrier microabscesses and dermal and epidermotropic lymphocytic atypia.

RESULTS

Seventy-six patients had HMF. Presentation in females (59.21%; p = .04) and patch stage (88.16%; p = .01) in HMF were significant, and HMF presented at a younger mean age when compared to non-HMF. Both groups had equal intensity of epidermotropism, with HMF showing milder dermal infiltrates and significantly less dermal atypia. Pautrier microabscesses were significantly commoner in non-HMF (LR 10.76; p < .01). 94.74% of HMF were CD4-/CD8+.

CONCLUSION

HMF presents at a lower age and earlier stage with female predominance compared to non-HMF. Because of milder dermal infiltrates, less dermal atypia, and Pautrier microabscesses, the diagnosis of HMF requires correlation with clinical features and careful assessment of epidermotropic cells.

Thymocyte selection-associated high-mobility group box as a potential diagnostic marker differentiating hypopigmented mycosis fungoides from early vitiligo: A pilot study

BACKGROUND

Hypopigmented mycosis fungoides is a rare variant of mycosis fungoides that may mimic many benign inflammatory hypopigmented dermatoses, and as yet there is no identified marker to differentiate between them.

AIM

The aim of this study was to study the expression of thymocyte selection-associated high-mobility group box (TOX) in hypopigmented mycosis fungoides and one of its inflammatory mimickers (early active vitiligo) to assess its potential as a differentiating diagnostic marker.

METHODS

A case-control study was done using immunohistochemical analysis of TOX expression in 15 patients with hypopigmented mycosis fungoides and 15 patients with early active vitiligo. Immunohistochemical analysis was done via a semi-quantitative method and an image analysis method.

RESULTS

Hypopigmented mycosis fungoides showed a statistically significant higher expression of TOX than early active vitiligo. The expression of TOX was positive in a majority of hypopigmented mycosis fungoides cases (14 cases, 93.3%), while only one case (6.7%) of vitiligo was weakly positive. TOX also displayed 93.3% sensitivity and specificity, with a cut-off value of 1.5.

LIMITATIONS

This was a pilot study testing hypopigmented mycosis fungoides against only a single benign inflammatory mimicker (early vitiligo). Other benign mimickers were not included.

CONCLUSION

Our findings showed that TOX expression can differentiate hypopigmented mycosis fungoides from early active vitiligo which is one of its benign inflammatory mimickers, with a high degree of sensitivity and specificity.

Mycosis Fungoides Variants

Mycosis fungoides (MF) is a cutaneous T-cell lymphoma that usually manifests as patches and plaques with a propensity for nonphotoexposed areas. MF is a common mimicker of inflammatory and infectious skin diseases, because it can be manifested with a wide variety of clinical and pathologic presentations. These atypical presentations of MF may be difficult to diagnose, requiring a high level of suspicion and careful clinicopathologic correlation. Within this array of clinical presentations, the World Health Organization classification recognizes 3 MF variants: folliculotropic MF, pagetoid reticulosis, and granulomatous slack skin. These 3 variants, as well as hypopigmented MF, are addressed in this article.

Hypopigmented mycosis fungoides: a review of its clinical features and pathophysiology

Several distinct clinical forms of mycosis fungoides have been described. Hypopigmented mycosis fungoides should be regarded as a subtype of mycosis fungoides, insofar as it presents some peculiar characteristics that contrast with the clinical features of the classical form. Most patients with hypopigmented mycosis fungoides are younger than patients typically diagnosed with classical mycosis fungoides. In addition to typical dark-skinned individuals impairment, hypopigmented mycosis fungoides has also been described in Asian patients. The prognosis for hypopigmented mycosis fungoides is much better than for classical mycosis fungoides: hypopigmented mycosis fungoides is diagnosed when there are only patches of affected skin, and lesions usually will not progress beyond terminal stages, although they can persist for many years. Diagnosis should involve clinicopathologic correlation: skin biopsy analysis often reveals intense epidermotropism, characterized by haloed, large, and atypical CD8+ lymphocytes with convoluted nuclei, in contrast to mild to moderate dermal lymphocytic infiltrate. These CD8+ cells, which participate in T helper 1-mediated immune responses, prevent evolution to mycosis fungoides plaques and tumors and could be considered the main cause of the inhibition of melanogenesis. Therefore, hypopigmentation could be considered a marker of good prognosis for mycosis fungoides.

Annular hypopigmented mycosis fungoides: a novel ringed variant

Hypopigmented mycosis fungoides (MF) is a relatively uncommon variant of cutaneous lymphoma that is mostly seen in darker skin types. We present a novel and unique clinical presentation in an African-American female patient, consisting of regular hypopigmented annular rings in areas of normal skin and in more typical hypopigmented patches of MF. The lesions appeared diffusely on all extremities, anterior chest and back. Histopathologic examination showed an atypical lymphocytic infiltrate at the dermal-epidermal junction with epidermotropism and few Pautrier's collections. The patient was otherwise healthy and improved with narrowband ultraviolet (UV)-B. This case represents a presentation of a most unusual variant of hypopigmented MF, for which we propose the name 'annular hypopigmented MF'.

History: Frederic Woringer (1903-1964) and Woringer-Kolopp disease

The two most famous dermatologic eponyms born in Strasbourg are Pautrier microabscess and Woringer-Kolopp disease. Frederic Woringer (1903-1964) was one of Pautrier's students, who had been in charge of the Laboratoire d'Histopathologie Cutanée in Strasbourg from 1930 until his death. He achieved a brilliant career in the field of dermatopathology and was very active during the great period between World War I and II. His name is linked to a rare disease, pagetoid reticulosis, which he actually misunderstood, as he was at first convinced that the characteristic intraepidermal changes were due to Paget cells. In this article, we show for the first time the original correspondence between Kolopp (who sent the case to Strasbourg) and Woringer, including discussion with masters such as Pautrier and Civatte. Civatte suggested that these mysterious intraepidermal cells might have common morphologic features with the recently described Sezary cells. After the first publication of pagetoid reticulosis, it took almost 40 years to establish a clear link with mycosis fungoides. It was Braun Falco who named the disease after Woringer and Kolopp in 1974. Woringer would certainly be surprised to know that his name is still world famous, thanks to a rare disease he was the first to extensively describe in 1939, a few days before the declaration of war.

Hypopigmented mycosis fungoides in Caucasian patients: a clinicopathologic study of 7 cases

BACKGROUND

Hypopigmented mycosis fungoides (MF) is a rare variant of cutaneous T-cell lymphoma. It is more frequent in dark-skinned or Asian patients, particularly children. Only 9 cases in Caucasian patients have been reported in the literature so far.

OBSERVATION

We describe 7 Caucasian patients (2 children and 5 adults) with hypopigmented MF. Histologic examination confirmed the diagnosis in all cases. The phenotype of neoplastic lymphocytes was T helper in 4 cases and T suppressor in 3 (2 of them children). Monoclonality of the T lymphocytes could be detected in hypopigmented lesions in all 7 cases with the use of a polymerase chain reaction technique. In 4 patients, polymerase chain reaction analysis of T-cell receptor-gene rearrangement after laser-based microdissection of the specimen revealed that the monoclonal population of T lymphocytes was confined mainly to the epidermis.

CONCLUSION

Hypopigmented lesions of MF can be observed in Caucasian patients. Children affected by MF often present with this rare clinical variant of the disease. Persistent or unusual hypopigmented lesions should be subjected to biopsy to avoid delay in the diagnosis of MF, especially in children.

Hypopigmented mycosis fungoides: frequent expression of a CD8+ T-cell phenotype

Hypopigmented mycosis fungoides (MF) is a form of cutaneous T-cell lymphoma in which hypopigmentation occurs in the absence of classic lesions of MF. Hypopigmented MF predominantly affects people with dark complexions. The natural history of this variant of cutaneous T-cell lymphoma is similar to that of conventional MF, although the disease onset is usually in childhood or adolescence. In a retrospective study we evaluated the clinical, histopathologic, immunohistochemical, and molecular characteristics of hypopigmented MF in 15 patients. Similar to other reports, the disease onset occurred in childhood and adolescence in most of the cases. The survival rate was comparable with that of classic MF. We did not observe progression to systemic disease or lymph node involvement. Histopathologically hypopigmented lesions were indistinguishable from hyperpigmented or erythematous patches. On immunohistochemical analysis a predominantly CD8+ infiltrate was detected in the majority of cases (nine of 15 patients). To determine whether epidermotropic CD8+ T cells represent the malignant T-cell clone or whether these cells are innocent, tumor-infiltrating T lymphocytes, we performed microdissection of epidermotropic CD8+ T cells and analyzed T-cell receptor-gamma chain gene for rearrangements. The epidermotropic CD8+ T lymphocytes showed clonal T-cell receptor gene rearrangement and therefore represented the malignant T-cell clone. We conclude that hypopigmented MF tends to occur in young people and that it belongs to the group of CD8+ cutaneous T-cell lymphomas in the majority of cases.

Profile and outcome of childhood mycosis fungoides in Singapore

Mycosis fungoides (MF) is the most common form of cutaneous T-cell lymphoma. It usually occurs in middle-aged and elderly persons, although several reports have described its occurrence in young children. The aim of this study was to review the profile and outcome of childhood MF in Singapore from 1989 to 1998. A total of nine patients (six males and three females) were diagnosed with MF before the age of 21 years. There were four Chinese, four Malay, and one Indian. The age at the time of histologic diagnosis ranged from 6 to 20 years (mean 14.3 years). Eight of the nine patients presented with hypopigmented patches and plaques. According to TNM staging, three were in stage 1A and six in stage 1B. The treatment modalities included psoralen plus ultraviolet A (PUVA) (n = 5), UVB (n = 2), and potent topical steroids (n = 2). We found that PUVA induced a faster clinical remission, but maintenance PUVA was required to prolong the relapse-free interval. This study also highlighted the need to consider MF in the differential diagnosis of hypopigmented dermatoses in dark-skinned individuals, especially if they occur on the buttocks.

Clinical and histologic spectrum of human T-cell lymphotropic virus type I-associated lymphoma involving the skin

BACKGROUND

Adult T-cell leukemia/lymphoma (ATL) is associated with infection with human T-cell lymphotropic virus type I (HTLV-I).

OBJECTIVE

The objective was to describe the clinical, histopathologic, and immunologic features in three patients with ATL involving the skin.

METHODS

Clinical histories and skin biopsy specimens were reviewed. Immunophenotypic studies were performed on peripheral blood lymphocytes (three patients) and on skin biopsy specimens (one patient).

RESULTS

Serologic testing in each patient was positive for HTLV-I. Specific cutaneous lesions of ATL were diverse. Histologic features included markedly epidermotropic lymphoid infiltrates and dermal aggregates of lymphocytes and macrophages resembling granulomas. One patient died 3 months after diagnosis; the other two are alive with residual lymphoma.

CONCLUSION

A spectrum of clinical, histologic, and immunophenotypic features are seen in ATL involving skin. Those cases with a chronic course may resemble mycosis fungoides clinically and histologically. Serologic testing for HTLV-I is recommended in all patients with cutaneous lymphoma from endemic areas and in those with other risk factors for HTLV-I infection.

Adolescence mycosis fungoides: an unusual presentation with hypopigmentation

Mycosis fungoides (M.F.) is a rare cutaneous malignancy of childhood and adolescence. The disease commonly presents with the classic sequence of erythematous patches and plaques. Hypopigmentation as the presenting symptom is distinctly rare. This is the 9th case report of M.F. presenting with hypopigmentation in a patient under 20 years of age. The disease was only partially controlled with PUVA therapy, necessitating nitrogen mustard treatment.

Hypopigmented mycosis fungoides

We report the case of a 25-year-old Jamaican woman with hypopigmented mycosis fungoides. She first developed a hypopigmented patch on her arm at the age of 11 years. Further lesions developed on the trunk and limbs over a period of 10 years. The lesions were completely impalpable. Skin biopsy showed an infiltrate of atypical lymphocytes, some with cerebriform nuclei, suggesting a diagnosis of mycosis fungoides. The lesions cleared with PUVA therapy.

Role of epidermal Langerhans cells in viral infections

Langerhans cells function as highly potent antigen-presenting cells in the epidermis. In the last few years, their role in viral infections has been studied in various experimental systems. They have been shown to be involved in the pathogenesis of a number of infections of viral origin. These include vaccinia virus, human papilloma virus, herpes simplex virus, foot and mouth disease virus and human retrovirus infections. Studies on the effect of various factors, that are known to modulate the activity and density of Langerhans cell in the epidermis, may lead in the future to the development of new strategies aimed at inhibiting virus infections or even eradicating latent infection.

Electron microscopic and immunolabeling studies of the lesional and normal skin of patients with mycosis fungoides treated by total body electron beam irradiation

Biopsy specimens were taken from lesional and normal skin of nine patients with mycosis fungoides before and after total body electron beam therapy. By electron microscopy, lesional skin had one and one-half to ten times as many epidermal Langerhans cells and indeterminate cells as did the normal skin. In successfully treated lesional skin 1 month after the end of electron beam therapy, the density of epidermal Langerhans cells and indeterminate cells had decreased markedly. In incompletely resolved lesions, Langerhans cells and indeterminate cells were still at pretreatment levels. Epidermal T6 and Ia antigens showed the same pattern of response. Epidermal cell suspensions from lesional and normal skin before and after electron beam therapy were assayed for epidermal thymocyte activating factor. The values of production of this factor did not correlate with the source of the epidermal cells, response to therapy, or the patient's disease course. Skin lesions resembling xerosis and parapsoriasis and histologically lacking the criteria for mycosis fungoides appeared during clinical remissions. These nonspecific skin lesions had densities of epidermal Langerhans cells, indeterminate cells, and T6-positive and Ia-positive cells comparable to levels found in pretreatment lesional skin.

Does radiation-induced abrogation of skin Langerhans cell functions lead to enhanced incidence of skin tumors in patients with genetic disorders of DNA repair?

A hypothesis is presented which states that persons with the genetic disorders xeroderma pigmentosum and ataxia-telangiectasia, manifested by a deficiency of DNA repair, develop cutaneous tumors due to the elimination of reticuloendothelial system cells (Langerhans cells) in the skin, and the subsequent loss of control of epidermal cellular elements.

The lymph node in mycosis fungoides: a light and electron microscopy and immunohistological study supporting the Langerhans' cell-retrovirus hypothesis

This paper describes the light and electron microscopy and monoclonal antibody findings in the lymph nodes of nine patients with mycosis fungoides. Four cases showed dermatopathic change characterized by close association between small convoluted T4 lymphocytes and T6 antigen-presenting cells (Langerhans' and indeterminate dendritic cells) in the sinuses and paracortical zones. The T4:T8 ratio was between 3 and 5:1. One case showed dermatopathic change but included large convoluted T4 lymphocytes and occasional T10 lymphocytes. The T4:T8 ratio was 4:1. The antigen-presenting cells were mostly T6 negative (interdigitating reticulum cells). One case showed extensive paracortical expansion by small and large convoluted T4 lymphocytes. The T4:T8 ratio was 20:1. Few B lymphocytes and antigen-presenting cells were present. Two cases showed partial and one case total effacement by atypical lymphoid tissue. This included small and large convoluted T4 lymphocytes and T4 immunoblasts. The T4:T8 ratios were between 30 and 40:1. The changes in their antigen-presenting cell population were complex. Langerhans' cells in one case generally failed to express T6 antigen and in two displayed histiocyte features. In one case, both immature and budding type C retrovirus-like particles were identified in Langerhans cells. One extracellular mature type C virus-like particle was identified in another case. No ultrastructural distinction could be made between similarly sized primary lysosomes and possible intracytoplasmic mature type C retrovirus particles. These findings support the hypothesis that mycosis fungoides may represent an altered dermatonodal cycle resulting from an interaction between retrovirus, Langerhans' cells and lymphocytes.

Unusual clinical presentation of epidermotropic cutaneous lymphoma. Small hypopigmented macules

A 35-year-old black woman developed numerous vitiligo-like small hypopigmented macules on the upper and lower extremities. Histologically the lesions were consistent with epidermotropic mycosis fungoides or pagetoid reticulosis. The patient is presented because of a clinical picture unusual for either of the above microscopic diagnoses.

Woringer-Kolopp disease. A form of mycosis fungoides

Woringer-Kolopp disease usually manifests as a solitary cutaneous patch or several patches confined to a single body region. While most cases have a good prognosis, there have been rare reports of cases with an aggressive course and a fatal outcome. The authors present two women who are alive with this condition, which, they believe is a variant of mycosis fungoides.

The intracutaneous growth of murine lymphomas: epidermal invasion is characteristic of multiple tumor phenotypes

Affinity of lymphoid cells for the epidermis (epidermotropism) is characteristic of the cutaneous T-cell lymphomas, mycosis fungoides and the Sézary syndrome. Consistent with numerous studies indicating that mycosis fungoides is a neoplasm of OKT4+T8- ("helper/inducer") T lymphocytes is the possibility that epidermotropism is a phenotypic hallmark of this subset of malignant T cells. This proposal was investigated in mice using 8 phenotypically characterized lymphomas of BALB/c origin: 3 histiocytic (phagocytic, lysozyme-positive, FcR+, Ig-, Thy 1-), 1 B-cell (IgM+, FcR+, Thy 1-), and 4 T-cell (Ig-, Thy 1+) lines, including 1 with markers of mouse helper/inducer T cells (Lyt1+23-), 2 with suppressor/cytotoxic markers (Lyt1-23+), and 1 with markers of immature thymocytes (Lyt1+23+). The intracutaneous growth pattern of these lines was studied on hematoxylin and eosin-stained sections through the centers of tumors obtained at times after intradermal injection into parallel groups of syngeneic mice. All of these lymphomas manifested variable epidermotropism that followed a typical sequence. Following dermal growth and spread to the dermal-epidermal junction, tumor cells appeared within the stratum spinosum. Subsequently, collections of cells appeared in spaces within the epidermis (Pautrier-like microabscesses) in tumors greater than 2 cm in diameter, coincident with early epidermal necrosis. Thus, in this animal model it is clear that the intraepidermal invasion/growth does not correlate with the helper/inducer T-cell surface phenotype. These observations are nonetheless consistent with recent studies using monoclonal antibodies to cell surface antigens which have demonstrated a heterogeneity of lymphoid cell subsets within the epidermis in lesions of mycosis fungoides and of other malignant and benign dermatoses.

Localized epidermotropic reticulosis (Woringer-Kolopp disease)

In order to clarify the biologic behavior and establish clinical and histologic criteria for the diagnosis of a cutaneous disease originally described by Woringer and Kolopp, we examined fifteen new cases and reviewed thirteen reports. The disease presents as a single, chronic, asymptomatic, circinated, scaly plaque. It preferably involves distal extremities and affects middle-aged individuals, as well as a considerable number of youths. The male to female ratio is 2:1. The treatment of choice is surgical excision or radiotherapy. One lesion resolved with an intralesionally administered steroid. Follow-up data of the twenty-eight cases suggest that this is a benign lesion. Paradoxically, its atypical microscopic features contrast with its benign clinical appearance and biologic behavior. The lower epidermis appears focally infiltrated by large atypical mononuclear cells that spare the dermis. Ultrastructural observations suggest that these are stimulated T lymphocytes, which sometimes are mixed with histiocytes. We propose the term "localized epidermotropic reticulosis" for this distinct clinicopathologic entity, which is different from mycosis fungoides.

Hypopigmented mycosis fungoides: report of five cases with ultrastructural observations

Five dark-skinned individuals presented with widespread well-demarcated hypopigmented lesions, biopsy of which revealed the histopathological features of mycosis fungoides. Ultrastructural studies showed focal invasion of the epidermis by mycosis cells with degenerative changes in adjacent melanocytes and keratinocytes. The majority of melanocytes exhibited swelling of cytoplasmic organelles and disordered melanogenesis with production of spherical incompletely melanized melanosomes. In addition disintegrating melanocytes were occasionally seen. Perifollicular repigmentation within hypopigmented areas occurred in two patients following clearing of the epidermal infiltrate with PUVA therapy. Mycosis fungoides may present with areas of cutaneous hypopigmentation.

Demonstration of histiocytes in the epidermal infiltrate of mycosis fungoides

The presence of histiocytes in the epidermal and dermal infiltrate of mycosis fungoides was observed histochemically by revealing a diffuse pattern of acid alpha-naphthyl acetate esterase (ANAE) activity in the cytoplasm, and immunohistochemically by demonstrating the presence of histiocyte-specific 'enzymes', lysozyme, alpha-I-antitrypsin and alpha-I-antichymotrypsin. Histiocytes in the infiltrate of mycosis fungoides may be involved in antigen processing and interaction with T lymphocytes.

The use of a double-label immunoperoxidase monoclonal antibody technique in the investigation of patients with mycosis fungoides

Using a double-labelling immunoperoxidase and monoclonal antibodies raised against T helper and T suppressor cells and Langerhans cells, we have found that the clinically involved skin of seventeen mycosis fungoides (MF) patients shows an increase in number of Langerhans cells which are in contact with T helper lymphocytes. T suppressor lymphocytes are also present, but are generally seen singly situated at a distance from the T helper/Langerhans cell clusters.

Mycosis fungoides presenting as areas of hypopigmentation: a report of three cases

In three patients with histologically documented mycosis fungoides, all or most of the lesions were hypopigmented. Unsuspected microscopic foci of mycosis fungoides were found in a purely macular hypopigmented area in one of these patients who had been treated with vitiligo 15 years earlier. Two of the patients were black, and one was Latin American. Repigmentation in all patients followed treatment with carmustine (BCNU) and mechlorethamine.

In situ identification of Langerhans cells in the dermal infiltrate of cutaneous T cell lymphoma

A population of cells showing the surface phenotype of Langerhans cells (LCs) was identified in the dermal infiltrates of cutaneous T cell lymphoma (CTCL). Peroxidase-conjugated OKT6, a monoclonal antibody reactive with epidermal LCs, was used to directly label frozen tissue sections of diseased skin from twenty-three patients with CTCL, two patients with secondary cutaneous involvement by a B cell lymphoma, and three patients with lymphocytoma cutis. OKT6-reactive cells represented a significant although minor population in the dermal infiltrate of twenty-two of the twenty-three CTCL biopsies, accounting for up to 5% of the cells. Double-labeling studies revealed that the OKT6-positive cells also exhibited Ia but not T cell antigens. Since OKT6-reactive cells were not found in either the B cell lymphomas or lymphocytoma cutis, their presence in a malignant infiltrate is suggestive of a T cell neoplasm.

The relationship between T lymphocyte subsets and Ia-like antigen positive nonlymphoid cells in early stages of cutaneous T cell lymphoma

Immunofluorescence studies were carried out in cutaneous T cell lymphoma (mycosis fungoides) in order to analyse the microanatomical relationship of the different T lymphocyte subsets (inducer and suppressor/cytotoxic cell populations) to large nonlymphoid Langerhans-type and so-called "indeterminate" or interdigitating cells. The conventional and mouse (monoclonal) antibodies were used in various combinations using fluorescein and rhodamine labeled second layers. In 5 of the 7 cases studied the dermal infiltrate consisted of numerous T (HuTLA+) lymphocytes, 80-90% of which expressed the inducer phenotype (HuTLA+,OKT4+). Most of these cells formed close contact with large cells exhibiting large amounts of Ia-like antigens. These cells corresponded to the interdigitating and indeterminate cells in the sections. By contrast, only small numbers (10-20%) of T cells of suppressor/cytotoxic type (HuTLA+,OKT8+) were seen. These did not show a close affinity to the Ia-like antigen positive nonlymphoid component but appeared to have a predilection for the epidermis. Epidermal Langerhans cells, also strongly Ia-like antigen positive, were further defined by 2 monoclonal antibodies reacting with a cortical thymocyte antigen HTA-1. Although Langerhans cells are probably related to the Ia-like antigen positive dermal cells only a few of the abundant latter population were HTA-1+. In the remaining 2 cases, larger populations of OKT8+ (suppressor/cytotoxic) cells were seen and could be heralding a particularly benign course. These observations indicate a close functional relationship between the lymphoid and Ia-like antigen positive dermal cells during the pre-malignant phase of cutaneous T cell lymphoma.