Perineural and intraneural cutaneous granulomas in granulomatous mycosis fungoides mimicking tuberculoid leprosy.

BACKGROUND: Histological similarities between granulomas and granulomatous mycosis fungoides (GMF) may lead to misdiagnoses of sarcoidosis or leprosy. METHODS: This report presents four patients with GMF in whom skin biopsies showed perineural and intraneural granulomas that were confused with tuberculoid leprosy granulomas. RESULTS: Patient 1 presented with erythematous plaques and bulky nodules. Biopsy findings suggested cutaneous sarcoidosis. Tumor resection showed granulomatous infiltrate extending to the fascia and skeletal muscle. Clinicopathological correlations permitted a diagnosis of GMF. Patient 2 presented with erythematous plaques. Skin biopsies had indicated sarcoidosis. Resection of a thigh nodule excluded leprosy, and GMF was diagnosed. Patient 3 presented with scaly, hyperpigmented plaques. Biopsy showed diffuse granulomatous inflammation with epithelioid and giant cells, abundant lymphocytes, and some eosinophils, and indicated GMF. Patient 4 presented with pruritic, erythematous plaques. Biopsy of an indurated mammary plaque initially indicated sarcoid granulomatous inflammation. Biopsy review suggested GMF. CONCLUSIONS: This study highlights both the diagnosis of GMF, and granulomatous cutaneous nerve injury in GMF and its possible confusion with leprosy granulomas. The histological diagnosis of GMF includes: (i) a granulomatous infiltrate rich in giant cells, emperipolesis, histiocytic cells, and scattered eosinophils, which may reach the fascia and muscle; (ii) the absence of elastic fibers or their phagocytosis by giant cells; and (iii) lymphocytes that may show atypia and epidermotropism. Deep biopsies reveal GMF diagnostic changes and, in conjunction with clinicopathological correlations, exclude a diagnosis of leprosy and support one of GMF, thus facilitating its appropriate management.

Childhood hypopigmented mycosis fungoides: a commonly delayed diagnosis.

Primary cutaneous lymphomas (PCLs) are exceedingly rare in children and adolescents, with mycosis fungoides (MF) being the most frequent PCL diagnosed in childhood. There are numerous unusual clinical variants of MF, including the hypopigmented type form (HMF). HMF is exceptional overall, but comparatively common among children. We present an 8-year-old boy with a 3-year history of progressive, generalised, scaly, hypopigmented round patches and few erythematous papules. He was first diagnosed with pityriasis alba (PA), and moisturisers were prescribed with no improvement. Skin biopsy showed typical features of MF, and the patient was successfully treated with narrowband ultraviolet B. HMF may simulate atopic dermatitis, PA, pityriasis lichenoides, tinea versicolour, vitiligo, postinflammatory hypopigmentation or leprosy. Therefore, persistent and unusual hypopigmented lesions should be biopsied to rule out this rare variant of MF.

Borderline tuberculoid leprosy mimicking mycosis fungoides.

A 65-year-old unemployed man, originally from Michoacán and currently living in Toluca, state of Mexico, presented for medical consultation for disseminated dermatosis in all body segments. The condition was limited to the head and neck, was bilateral and symmetrical, and was characterized by infiltrated and confluent erythematous-edematous plates of diverse diameter covering 90% of the upper and lower extremities (Figure 1). The ailment had 2 years' evolution and a progressive course. The patient was diagnosed in private practice as having atopic dermatitis. After exacerbation of symptoms, he was treated with deflazacort and hydroxychloroquine with no improvement. Results from lesion biopsies revealed sarcoidal granulomas and the patient was therefore referred to the dermatology department at the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán for further study and treatment with the presumptive diagnosis of mycosis fungoides vs sarcoidosis.

Clinicopathologic profile of hypopigmented mycosis fungoides in India.

BACKGROUND: Hypopigmented mycosis fungoides (HMF) is an under recognized disease in India, which is often mistaken for Hansen disease or vitiligo, resulting in delayed diagnosis and treatment. AIM: To describe the clinical, histopathologic and immunohistochemical features of HMF in Indian patients. MATERIALS AND METHODS: All cases presenting as hypopigmented lesions that were signed out as MF between 2001 and 2009 (15 cases) were included. Clinical data and histopathology slides were reviewed. Immunostains for CD4, CD8, and CD1a were done, where tissue was available. RESULTS: The age ranged from 14 to 38 years with a male preponderance. The commonest presentation was multiple hypopigmented patches on limbs and trunk with the duration of the lesions varying from 4 months to 14 years. All cases showed a psoriasiform/lichenoid epidermal pattern, disproportionate epidermotropism, basilar tagging of lymphocytes, monomorphous lymphocytes, haloed lymphocytes, and wiry dermal collagen. Other important findings were infiltration of hair follicles, larger epidermal lymphocytes, atypia of dermal lymphocytes, and stuffed dermal papillae. Dermal edema was absent in all cases. Immunohistochemistry done on 10 cases showed a CD8 phenotype in 6 cases and CD4 phenotype in the remaining 4 cases. CONCLUSIONS: Histopathology supplemented by immunohistochemistry is reliable in making a diagnosis of HMF. It is important to be aware of this uncommon, yet significant disease.

A study of clinicopathologic profile of 15 cases of hypopigmented mycosis fungoides.

BACKGROUND: Mycosis fungoides (MF) is cutaneous lymphoma of the T-cell lineage. Hypopigmented MF is a clinical variant of MF, described mainly in Asians. This is a retrospective clinicopathologic analysis of hypopigmented MF at a tertiary care center. AIMS: To describe the clinicopathologic profile of hypopigmented MF. METHODS: Records of clinicopathologic notes over a 5-year period ranging from January 2005 up to December 2009 were reviewed over a period of 3 months, of which 15 cases were diagnosed with hypopigmented MF based on clinicopathologic correlation. RESULTS: Hypopigmented MF was found to be more common in males, and between second and fourth decades of life. The latent period between onset and diagnosis was around 3.83 years. Most of the patients were asymptomatic 80% (12/15), with skin changes of subtle atrophy in 46.66% (7/15), scaling in 20% (3/15) and focal changes of poikiloderma in 26.66% (4/15) patients. Most common sites of distribution of the lesions were the trunk and extremities. Many of the cases had been clinically mistaken for Hansen's disease prior to correct diagnosis. Marked epidermotropism and tagging of epidermis by large lymphocytes characterizes the condition histopathologically. Of the 15 cases, immunohistochemistry was possible in 10 cases, of which 8 showed predominant CD8 positive epidermotropic infiltrates and two cases showed absence of CD8 positive and CD4 positive lymphocytic infiltrate in the epidermis. CONCLUSION: Hypopigmented MF presents as hypopigmented asymptomatic patches without any erythema or infiltration in its early stage and mimics Hansen's disease. Skin biopsy clinches the diagnosis.

Arcuate, annular, and polycyclic inflammatory and infectious lesions.

Common shapes encountered in dermatologic diseases include linear, nummular, annular, polycyclic, and arciform. The last three have a relatively restricted differential, which must be entirely explored. It is not uncommon for a single disease to present in annular, arciform or polycyclic configurations; moreover, the lesions may evolve from being arciform to annular and then become polycyclic. Regardless, recognizing the arrangement of the defect will undoubtedly help in making a diagnosis and guiding subsequent management. We explore diseases that often present in annular, arciform, and/or polycyclic forms.

Early mycosis fungoides vs. inflammatory mimics: how reliable is histology?

BACKGROUND: The histologic diagnosis of early mycosis fungoides (MF) and its distinction from inflammatory dermatoses is challenging, owing to the overlap of several features. AIMS: 1) To assess the efficacy of histologic criteria to diagnose early MF, 2) to study their utility in differentiating inflammatory mimics of MF. METHODS: We retrospectively reviewed slides from 50 cases clinically/histologically suspicious for MF. The diagnoses were established based on response to treatment and follow-up. The slides were analyzed double-blinded by two observers independently. Twenty-eight histologic criteria were assessed and each criterion was graded. Univariate analysis was performed on the results. RESULTS: There were 17 cases of MF and 33 of inflammatory dermatoses. Of the 28 criteria, the following 15 achieved significance on univariate analysis: disproportionate epidermotropism, tagging of lymphocytes along the basal layer, haloed lymphocytes, convoluted lymphocytes, Pautrier's abscesses, larger epidermal lymphocytes, wiry dermal collagen, absence of edema, eccrine infiltration, folliculotropism, follicular mucin, involvement of papillary and reticular dermis, monomorphous infiltrates, and atypia of dermal lymphocytes. The criteria that were 100% specific for MF included convoluted lymphocytes, eccrine infiltration, and follicular mucin. Absence of edema was 100% sensitive and specific in distinguishing MF from its inflammatory mimics. CONCLUSIONS: A combination of histologic patterns and cytology of lymphocytes is reliable in distinguishing MF from inflammatory dermatoses. No single criterion is effective in achieving this. Rather than merely recording the presence or absence of a criterion, grading each of them adds objectivity to the diagnosis.

Dermatological disorders resembling leprosy.

Three dermatological conditions - epidermolysis bullosa dystrophica (EBD), granuloma multiforme (GM) and mycosis fungoides (MF) were diagnosed elsewhere as leprosy either clinically or histologically. Although the morphology of the lesions were suspicious of leprosy there were few striking clinical findings which were unfavourable. Leprosy is still an important disease that should not be missed. However, the recognition of these skin disorders is highlighted so that unnecessary and prolonged treatment for leprosy can be avoided in endemic countries.

Distribution of lymphocytes with interleukin-2 receptors (TAC antigens) in reactive lymphoproliferative processes, Hodgkin's disease, and non-Hodgkin's lymphomas. An immunohistologic study of 300 cases.

The authors investigated the distribution of interleukin-2 receptors (TAC antigen) in the lymph nodes of 300 patients with lymphoproliferative disorders. They used fresh-frozen sections to evaluate a possible correlation between the immunophenotype of specific lymphoid disorders and the presence or absence of TAC expression and to determine whether the TAC positivity of lymphoid cells contributes to the characterization of lymphoproliferative processes. All of the cases had previously been studied with a large screening panel of monoclonal antibodies and polyclonal antisera. Among 85 patients with a variety of benign reactive processes, the lymph nodes from 47 contained TAC-bearing lymphocytes in various patterns of distribution. Of 41 patients with Hodgkin's disease, 37 had TAC-bearing lymphocytes. Of 26 B-cell, well-differentiated lymphocytic lymphomas (WDL), 14 were diffusely TAC-positive and one had TAC-bearing cells in random distribution. Six cases of intermediate lymphocytic lymphoma were also studied, and three showed randomly distributed TAC-bearing lymphocytes. Of 19 patients with follicular or follicular and diffuse, poorly differentiated lymphocytic (PDL) lymphoma, 14 were TAC-positive. All 3 diffuse PDL lymphomas studied were TAC-negative. Among 23 cases of B-cell and 5 cases of T-cell mixed cell lymphoma, 15 and three, respectively, had TAC-positive lymphocytes. Of 39 large cell lymphomas (B-cell, 33; T-cell, 6), 14 were TAC-positive. All 13 cases of hairy cell leukemia were diffusely positive. Of 23 T-lymphoblastic lymphomas, only 1 showed positive TAC reactivity, which was focal. Of 5 cases of cutaneous T-cell lymphoma, 2 had TAC-bearing lymphocytes. Our study indicates that the TAC antigen is not lineage-specific, and that it may be expressed by lymphoid cells regardless of their phenotype.

Immunoperoxidase techniques applied to dermatopathology.

Immunoperoxidase techniques provide the pathologist with the capability for staining a wide range of antigens in tissue sections. More than 100 different antigens have been successfully demonstrated in fixed paraffin sections; other antigens can only be visualized in frozen sections. This latter group particularly includes lymphocyte surface antigens detectable by monoclonal antibodies. This review describes the current state of the art and provides several illustrations of the use of monoclonal antibodies for the identification of T-lymphocyte phenotypes in frozen section from cases of leprosy, mycosis fungoides, halo nevus, Kaposi's sarcoma, lichen planus and atopic dermatitis. Technical details and potential applications are discussed. The growing availability of commercial immunostaining kits makes these techniques more accessible to the surgical pathologist; indeed a whole new range of truly specific, special stains are available, as pathologists we must simply learn to use them.