Granulomatous slack skin: a clinicopathological and immunohistochemical study of three cases

Spatial transcriptomics reveals heterogeneity of macrophages in the tumor microenvironment of granulomatous slack skin

Granulomatous slack skin (GSS) is an extremely rare subtype of cutaneous T-cell lymphoma accompanied by an abundant number of macrophages and is clinically characterized by the development of pendulous skin folds. However, the characteristics of these macrophages in GSS remain unclear. Here, we conducted a spatial transcriptomic study on one frozen GSS sample and drew transcriptomic maps of GSS for the first time. Gene expression analysis revealed the enrichment of three clusters with macrophage transcripts, each exhibiting distinct characteristics suggesting that their primary composition consists of different subpopulations of macrophages. The CD163+ /CD206+ cluster showed a tumor-associated macrophage (TAM) M2-like phenotype and highly expressed ZFP36, CCL2, TNFAIP6, and KLF2, which are known to be involved in T-cell interaction and tumor progression. The APOC1+ /APOE+ cluster presented a non-M1 or -M2 phenotype and may be related to lipid metabolism. The CD11c+ /LYZ+ cluster exhibited an M1-like phenotype. Notably, these cells strongly expressed MMP9, MMP12, CHI3L1, CHIT1, COL1A1, TIMP1, and SPP1, which are responsible for extracellular matrix (ECM) degradation and tissue remodeling. This may partially explain the symptoms of cutaneous relaxation in GSS. Further immunohistochemistry on four GSS cases demonstrated that CD11c predominantly marked granulomas and multinucleated giant cells, whereas CD163 was mainly expressed on scattered macrophages, appearing as a mutually exclusive pattern. The expression pattern of MMP9 overlapped with that of CD11c, implying that CD11c+ macrophages may be a source of MMP9. Our data shed light on the characteristics of macrophages in the GSS microenvironment and provide a theoretical basis for the application of MMP9 inhibitors to prevent cutaneous relaxation of GSS. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Cutaneous Hematolymphoid and Histiocytic Proliferations in Children

This article focuses on cutaneous hematopoietic neoplasms that are more likely to be encountered in the pediatric age-group and includes both lymphoproliferative and histiocytic disorders. The cutaneous hematologic disorders in children have a different epidemiologic profile to what is seen during adulthood. Although mycosis fungoides is the most frequent form of cutaneous lymphoma in adults, it is very rare in children. Because lymphoblastic leukemias and lymphomas are more frequent in the pediatric setting, cutaneous leukemic infiltrates are relatively common in this age-group. Similarly, histiocytic disorders are more common in children, particularly Langerhans cell histiocytosis and juvenile xanthogranuloma. Notably, the histiocytic disorders have undergone significant modifications on their nomenclature in the basis of the molecular characteristics that are present in them. A summary of the most frequent cutaneous hematopoietic disorders in children will be discussed further in this review.

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.

Topical nitrogen mustard for the treatment of granulomatous slack skin

Granulomatous slack skin (GSS) is a rare variant of mycosis fungoides in which inflammation leads to elastolysis manifested by pendulous skin folds with a predilection for flexural areas. Histologic findings include many multinucleated giant cells with large numbers of nuclei and loss of dermal elastic tissue. Definitive therapy has yet to be established, but recently interferon-alpha and radiation, interferon-gamma, and pentostatin have shown some success in the treatment of GSS. We present two cases of GSS treated with topical nitrogen mustard (chlormethine; mechlorethamine; mustine), one of whom has long-term remission and the other partial remission. Topical nitrogen mustard appears to be an effective skin-directed therapy for this rare condition.

Clinicopathological spectrum of mycosis fungoides

Cutaneous lymphomas represent a heterogeneous group of T-, NK- and B-cell neoplasms, with mycosis fungoides (MF) being the most common subtype. MF has a plethora of clinicopathological manifestations. Many variants of this lymphoma differ substantially from the 'classical' Alibert-Bazin disease and are therefore sometimes referred to as 'atypical' forms of the disease. This review addresses the whole clinicopathological spectrum of mycosis fungoides with respect to epidemiology, clinical, histopathological, immunophenotypic and genotypic features and the clinical course and prognosis of its variants: classical, erythrodermic, follicular, syringotropic, bullous/vesicular, granulomatous, poikilodermic, hypo- and hyperpigmented, unilesional, palmoplantar, hyperkeratotic/verrucous, vegetating/papillomatous, ichthyosiform, pigmented purpura-like, pustular and mucosal involvement in MF.

Acquired disorders of elastic tissue: Part II. decreased elastic tissue

Elastic fibers in the extracellular matrix are integral components of dermal connective tissue. The resilience and elasticity required for normal structure and function of the skin are attributable to the network of elastic tissue. Advances in our understanding of elastic tissue physiology provide a foundation for studying the pathogenesis of elastic tissue disorders. Many acquired disorders are nevertheless poorly understood owing to the paucity of reported cases. Several acquired disorders in which loss of dermal elastic tissue produces prominent clinical and histopathologic features have recently been described, including middermal elastolysis, papular elastorrhexis, and pseudoxanthoma-like papillary dermal elastolysis, which must be differentiated from more well-known disorders such as anetoderma, acquired cutis laxa, and acrokeratoelastoidosis. Learning objective At the conclusion of this learning activity, participants should have an understanding of the similarities and differences between acquired disorders of elastic tissue that are characterized by a loss of elastic tissue.

Granulomatous slack skin without evidence of a clonal T-cell proliferation

Granulomatous slack skin is a rare cutaneous disorder with less than 50 cases presented in the English-language literature. The disease is characterized by circumscribed erythematous lax skin accentuated most commonly in the axillary and inguinal areas. A strong association with a preceding or evolving diagnosis of mycosis fungoides or Hodgkin's disease has been reported. Previous reports describe the entity as a lymphoproliferative disease in the same spectrum as mycosis fungoides and Hodgkin's disease with a monoclonal T-cell population. Our case, without an evident beta-T-cell receptor rearrangement, suggests that not all cases of granulomatous slack skin are a result of an indolent lymphoma. Granulomatous slack skin probably represents a spectrum of diseases that can eventuate into a lymphoproliferative process.

Cutaneous lymphomas with prominent granulomatous reaction: a potential pitfall in the histopathologic diagnosis of cutaneous T- and B-cell lymphomas

The presence of a granulomatous reaction in lesions of cutaneous lymphomas has been described in the past in several cases. Especially in mycosis fungoides, a "granulomatous" variant of the disease has been well characterized. We studied the clinicopathologic features of cutaneous lymphomas with prominent granulomatous reaction, including both cutaneous T-cell lymphomas and B-cell lymphomas (primary cutaneous lymphoma 22, secondary cutaneous lymphoma one). Biopsies of 23 patients with histopathologic features of cutaneous T-cell lymphoma or cutaneous B-cell lymphoma with prominent granulomatous reaction were included in this study. A prominent granulomatous reaction was defined as the presence of a granulomatous component exceeding 25% of the dermal infiltrate. There were 14 cases of mycosis fungoides, two of subcutaneous panniculitis-like T-cell lymphoma, four of small/medium pleomorphic T-cell lymphoma, one of follicle center cell lymphoma, one of large B-cell lymphoma, and one of secondary cutaneous peripheral T-cell lymphoma. Altogether, a prominent granulomatous reaction could be observed in 1.8% of all patients with cutaneous lymphoma (primary or secondary) registered in the files of the Department of Dermatology of the University of Graz (Graz, Austria), demonstrating that there is a distinct, albeit small, proportion of cases revealing this peculiar reaction pattern. In seven cases a misdiagnosis of granulomatous dermatitis preceded the correct diagnosis for a period of 1-216 months, suggesting that sequential biopsies and complete phenotypic and molecular genetic analyses should be carried out in cases of "unusual" granulomatous dermatitis.

Anetoderma arising in cutaneous B-cell lymphoproliferative disease

Anetoderma is circumscribed atrophy of the skin due to a localized deficiency in elastic tissue. It can follow inflammatory skin diseases of several types, and occasionally is present in the skin around neoplasms. There are a few reports of anetoderma in the lesional skin of cutaneous lymphoma. We report on two patients who presented with multiple lesions of anetoderma and who later proved to have low-grade cutaneous B-cell lymphomas. One patient (Patient 1) is a 39-year-old man and the other patient is a 26-year-old woman who is a renal transplant recipient (Patient 2). Some biopsy specimens from the anetodermic skin of Patient 1 appeared to show an urticarial reaction, although plasma cells were present. A large nodule showed lymphoid follicles surrounded by plasmacytoid lymphocytes, with loss of elastic tissue in the adjacent dermis. The plasmacytoid cells stained overwhelmingly for lambda light chain, and staining of the urticarial lesions from this patient also showed a marked majority of lambda positive cells. Immunoglobulin heavy chain gene (IgH) rearrangements showed a dominant clonal pattern in the nodular lesion. We classified the disease in Patient 1 as marginal zone lymphoma and the disease in Patient 2 as a post-transplant lymphoproliferative disorder. Because of the intimate association of anetoderma and cutaneous B-cell lymphoproliferative disorders in these two patients, it seems possible that anetoderma could result from either a local effect of the neoplastic cells or associated inflammatory cells, especially neutrophils as in Case 1. The infiltrates of Case 1 had many interstitial neutrophils and only a few clonal plasmacytoid lymphocytes, indicating that this presentation of B-cell lymphoma can be a diagnostic pitfall. Given these two cases and similar ones in the literature, biopsy of lesional skin in anetoderma should be performed to ensure that lymphomatous infiltrates are not present. Even if plasma cells are sparse, studies to detect clonality are appropriate. Cutaneous B-cell lymphoma can be added to the list of associations of elastolysis and cutaneous lymphoma, which includes granulomatous slack skin (T-cell lymphoma) and cutis laxa (myeloma).

Granulomatous slack skin: an ultrastructural study

BACKGROUND

Granulomatous slack skin is a rare lymphoproliferative disorder characterized clinically by gradual development of pendulous folds of lax erythematous skin in flexural areas, and histologically by non-necrotizing granuloma, with numerous multinucleated giant cells, mononuclear histiocytes, and atypical lymphocytes associated with loss of elastic fibers. Although there are many reports describing the histological and immunophenotypic features of this disease, only a few have described the ultrastructural features.

METHODS

Here we report a case of granulomatous slack skin and describe the ultrastructural findings.

RESULTS AND CONCLUSION

We could detect some previously not noted abnormal findings in multinucleated giant cells, histiocytes, and atypical lymphocytes.

Granulomatous slack skin in childhood

Granulomatous slack skin is an uncommon cutaneous T-helper cell lymphoma closely related to mycosis fungoides. To the best of our knowledge this disease has not been previously described in children. We report on an 11-year-old boy who presented with painless slack skin masses in the neck, right axilla and arm, anterior wall of the abdomen, both inguinal regions, and the malleolar and dorsal aspects of the feet. The disease started 3 years earlier with erythematous lesions on the neck and wrists. Histologic examination of a specimen from the abdominal mass revealed an extensive lymphoid infiltrate with scattered multinucleated giant cells extending from the papillary dermis to the subcutis. The lymphoid cells showed the following immunophenotype: CD43+ (MT1), CD45+, CD45RO+, CD20-. The phenotype of the giant cells was lysozyme positive, CD68+ and Mac387-. The tumoral lymphoid cells had clonal rearrangement for the gene of the beta chain of the T-cell receptor (C beta TCR). The disease could be controlled with systemic glucocorticoids. Due to the presence of many histiocytes arranged in aggregates in the papillary and mid-dermis, this case was initially considered to be a cutaneous form of histiocytosis. We recommend deep and extensive biopsies in patients with slack skin disease.

Granulomatous slack skin. Report of a case and review of the literature

We describe a patient with granulomatous slack skin (GSS) who has been followed for 15 years and present clinical, histological, immunohistochemical, ultrastructural, cytogenetic, and molecular findings. The clinical and pathological aspects of the 20 cases of GSS reported in the recent literature are reviewed and compared with those of the present case.

Granulomatous slack skin: report of a case associated with Hodgkin's disease and a review of the literature

We report a case of granulomatous slack skin (GSS) associated with Hodgkin's disease, and review the literature on this entity. GSS, a variant of cutaneous T-cell lymphoma, clinically presents with erythematous patches in the flexures, which gradually transform into bulky, pendulous areas of skin. Histology shows an elastolytic granulomatous infiltrate, with atypical lymphoid cells, and occasional epidermotropism. As far as we are aware, 10 cases of GSS, including our patient, have been reported in detail. The male:female ratio of these cases is 9:1, and the age range 15-51 years. Five cases were associated with Hodgkin's disease, one with small lymphocytic lymphoma, and one developed cutaneous T-cell lymphoma. The axillae, abdomen and groins were the most frequently affected areas. No definitive management for GSS has been established. Surgery has been performed in localized forms, and systemic treatments have included corticosteroids, dapsone, chlorambucil, nitrogen mustard, and radiotherapy. Our patient was treated with chemotherapy for his Hodgkin's disease, and this resulted in complete remission of the lymphoma. Subsequent maintenance therapy with interferon-alpha produced good control of the cutaneous lesions.

Granulomatous slack skin

Granulomatous slack skin is an extremely uncommon form of cutaneous T-cell lymphoma. We report a case occurring in a 29-year-old man, who had generalized, progressive skin lesions evolving to nodular swellings and folds in the flexural regions, and peripheral blood and marrow involvement. The biopsies were initially misinterpreted as xanthogranuloma or granulomatous inflammation. Histologically, the entire dermis and subcutis was infiltrated by non-necrotizing granulomas comprising mononuclear histiocytes, multinucleated giant cells and small lymphoid cells with irregularly folded nuclei, associated with loss of elastic fibres. The small lymphoid cells showed focal epidermotropism. Immunohistochemical studies showed that they were of T-lineage (CD3+, CD43+, CD45RO+). The multinucleated giant cells, which showed reactivity with the histiocytic markers CD68 and Mac387, were highlighted by intense, thick membrane staining with CD45, CD43 and CD45RO. Ultrastructurally, they exhibited features of macrophages with numerous surface villous processes and lysosomes. Greater awareness of this entity may facilitate more prompt and accurate diagnosis, obviating a futile search for a non-existent infective aetiology.