Extrafacial indolent CD8‐positive cutaneous lymphoid proliferation with unusual symmetrical presentation involving both feet

Indolent CD8+ cutaneous lymphoid proliferation represents a recently described entity among cutaneous T‐cell lymphomas that typically presents with solitary skin lesions on the face or at acral sites and usually follows an indolent clinical course. Histopathologically, this entity is characterized by a dense dermal infiltrate of non‐epidermotropic, small‐ to medium‐sized pleomorphic CD8+ T‐cells of the non‐activated cytotoxic phenotype showing a clear‐cut grenz zone and a low proliferation index. Distinction from otherwise aggressive T‐cell lymphomas bearing a cytotoxic CD8+ phenotype is fundamental. We herein present an unusual case of indolent CD8+ cutaneous lymphoid proliferation presenting in bilateral symmetrical distribution on both feet and lacking the otherwise described grenz zone. Our case widens the spectrum of possible clinical and histomorphological variations of this entity. Taking into account the distinctive and unique clinical and microscopic features of all hitherto published cases of indolent CD8+ cutaneous lymphoid proliferation we suppose that this lymphoma subtype has to be included as a new and distinct entity in the World Health Organisation (WHO)‐/European Organisation for Research and Treatment of Cancer (EORTC)‐classification of cutaneous lymphomas.     

A review of the solitary cutaneous T‐cell lymphomas

Cutaneous T‐cell lymphomas (CTCL) account for almost 65‐92% of all cutaneous lymphomas, many of which usually present with multiple lesions. However, a number of well‐recognized and rare types of CTCL, including mycosis fungoides, can present in isolated fashion. These solitary lesions often run a relatively indolent clinical course but often pose diagnostic difficulties. We review histopathologically challenging solitary cutaneous T‐cell lymphomas, including criteria for diagnosis, clinical course and prognosis, particularly for primary cutaneous CD4+ small/medium pleomorphic lymphoma and indolent CD8+ lymphoid proliferation of acral sites. In addition, we suggest an algorithm and nomenclature to aid in the diagnosis of such problematic lesions.     

Indolent course of cutaneous gamma‐delta T‐cell lymphoma

Cutaneous gamma‐delta T‐cell lymphoma (γδTCL) is a rare malignancy that typically displays an aggressive clinical course. We present an unusual case of a 57‐year‐old woman with a 3‐year history of lower extremity nodules. Histopathologic, immunophenotypic and molecular genetic studies revealed a clonal, predominantly pannicular gamma‐delta T‐cell infiltrate, leading to a diagnosis of cutaneous γδTCL. The clinical course was characterized by rapid improvement within months of starting systemic corticosteroids, with relapse in ulcerations but no new lesions more than 3 years after onset of disease. Our case and seven previously reported patients with indolent and relatively localized cutaneous γδTCL provide evidence that not all cases of this entity carry a poor prognosis. This indolent subset adds complexity to treatment of cutaneous γδTCL.     

Primary cutaneous acral CD8+ T‐cell lymphoma of the ear: A case report

Primary cutaneous acral CD8+ T‐cell lymphoma (TCL) is a rare, distinct type of cutaneous TCL. Despite its worrisome histological appearance it has a benign clinical course. It is therefore important to recognize this as a distinct entity from other more aggressive CD8+ lymphomas, for which the management is very different.     

Cutaneous CD30‐positive lymphoproliferative disorders with CD8 expression: a clinicopathologic study of 21 cases

Lymphomatoid papulosis (LyP) and cutaneous anaplastic large cell lymphoma (ALCL) belong to the spectrum of cutaneous CD30+ lymphoproliferative disorders, an indolent form of T‐cell lymphoproliferative disease. We reviewed 21 cases of CD30+ lymphoproliferative lesions expressing cytotoxic profile (CD8+). Seven cases of cutaneous ALCL, 2 cases of systemic ALCL involving the skin, and 12 cases of LyP. The cases of LyP were predominated by small lymphocytes exhibiting a prominent epidermotropic pattern consistent with either type B or type D LyP. Four cases showed co‐expression of CD56. The ALCL cases included myxoid features, pseudoepitheliomatous change, and an intravascular component. In all cases that were primary in the skin an indolent clinical course was seen while one patient with systemic myxoid ALCL is in remission following systemic multiagent chemotherapy. The paucity of other neutrophils and eosinophils and concomitant granulomatous inflammation were distinctive features in cases of type B and type D LyP. CD30 and CD45 Ro positivity and a clinical course typical of LyP were useful differentiating features from an aggressive cytotoxic CD8+ T cell lymphoma. In all cases that were primary in the skin an indolent clinical course was observed. CD30 and CD45 Ro positivity and a clinical course typical of LyP were useful in preventing a misdiagnosis of an aggressive cytotoxic CD8+ T cell lymphoma.     

Disseminated CD8‐positive,CD30‐positive cutaneous lymphoproliferative eruption with overlapping features of mycosis fungoides and primary cutaneous anaplastic large cell lymphoma following remote solitary lesional presentation

CD8‐positive, CD30‐positive cutaneous lymphoproliferative disorders constitute a rare subset of T‐cell lymphoproliferative conditions, including variants of primary cutaneous anaplastic large cell lymphoma (ALCL), mycosis fungoides, lymphomatoid papulosis type D, cutaneous gamma‐delta T‐cell lymphoma and cutaneous peripheral T‐cell lymphoma. These entities share overlapping clinical, histopathologic and immunophenotypic features, presenting both a clinical and pathological diagnostic challenge. Presented here is a 73‐year‐old man with a disseminated, indolent CD30+, CD8+ cutaneous lymphoproliferative disorder with overlapping clinical and histopathological features of both mycosis fungoides and primary cutaneous ALCL, as well as features of lymphomatoid papulosis. To our knowledge, this is the first case of a generalized CD8+, CD30+ eruption with features of both mycosis fungoides and primary cutaneous ALCL arising following an episode of solitary primary cutaneous CD8‐positive ALCL.     

Acneiform primary cutaneous CD4‐positive small/medium pleomorphic T‐cell lymphoma with prominent necrosis

Primary cutaneous CD4‐positive small/medium pleomorphic T‐cell lymphoma (SMPTCL) is an indolent form of cutaneous lymphoma that usually presents in solitary fashion and is histopathologically characterized by nodular infiltration of small‐ to medium‐sized pleomorphic T‐cells. We report the case of a patient who presented with a 5‐year history of acneiform lesions on his face. Histopathologic examination of two lesions revealed a nodular infiltrate of small to medium‐sized lymphocytes with necrosis in the dermis. The proliferating cells were positive for CD2, CD3 and CD4 and negative for CD8, CD30 and CD56. They were positive for TIA‐1 and negative for perforin and granzyme B. The Ki67 proliferation index was approximately 10%. The neoplastic cells expressed programmed death‐1 and lacked expression of CXCL‐13, bcl‐6 and CD10. In situ hybridization for Epstein–Barr virus‐encoded RNA yielded a negative result. T‐cell receptor gene rearrangement showed identical T‐lymphocyte monoclonality in both lesions. In brief, we report a rare case of acneiform SMPTCL with prominent necrosis.     

ALK‐positive primary cutaneous T‐cell‐lymphoma (CTCL) with unusual clinical presentation and aggressive course

Anaplastic lymphoma kinase (ALK) expression is uncommon in primary cutaneous T‐cell‐lymphomas (CTCL). We report the case of a patient who was initially diagnosed with small plaque parapsoriasis, and eventually developed an unusual manifestation of CTCL 6 years later. The disease was characterized by aggressively ulcerating plaques and tumors of the entire skin. Histopathology revealed monoclonal proliferation of atypical T‐lymphocytes and CD30‐positive blasts with expression of ALK and identification of an ATIC‐ALK fusion protein. Extensive staging confirmed the primary cutaneous origin of the lymphoma. After failure of several conventional treatments including polychemotherapy, the patient finally achieved remission after receiving brentuximab‐vedotin, alemtuzumab and subsequent allogeneic stem cell transplantation. In the following, the patient developed inflammatory cutaneous lesions that pathologically showed no evidence for lymphoma relapse or classical cutaneous graft‐versus‐host disease. The patient responded to immunosuppression, but finally died from multi‐organ failure due to sepsis 8 months after stem cell transplantation. This is a rare instance of ALK positivity in a CTCL, most likely resembling CD30+ transformed mycosis fungoides, because it was not typical for cutaneous anaplastic large cell lymphoma (ALCL). In contrast to its role in systemic ALCL as favorable prognostic marker, ALK expression here was associated with an aggressive course.     

Acral angiokeratoma‐like pseudolymphoma in a middle‐aged woman

Acral angiokeratoma‐like pseudolymphoma is a rare type of pseudolymphoma presenting as dark‐red papules on the hand or foot. We describe a 59‐year‐old woman who presented with an unusual unilateral, clustered aggregate of scaly violaceous papules on the toe with an indolent course. Skin biopsy showed a prominent vascular proliferation associated with a dermal infiltrate of monoclonally rearranged T‐follicular helper phenotype T‐cells, in keeping with CD4+ small/medium T‐cell lymphoproliferative disorder (SMPTC‐LPD). Based on the unique clinical morphology, distribution of the lesions and dermoscopic appearance, a clinicopathologic diagnosis of acral angiokeratoma‐like pseudolymphoma was favored. This case demonstrates the importance of clinicopathological correlation in such diagnostically challenging patients who present with overlapping features on the spectrum of pseudolymphoma and cutaneous T‐cell lymphoma.     

Primary cutaneous CD4 positive small/medium T‐cell lymphoma with high proliferation index and CD30‐positive large lymphoid cells

Primary cutaneous CD4 positive small/medium pleomorphic T‐cell lymphoma (SMPTCL) represents a provisional subtype of primary cutaneous T‐cell lymphoma with indolent clinical course. A few aggressive fatal cases with increased proliferation rate and few infiltrating CD8 positive T‐cells have been reported. We describe a case of SMPTCL with an increased proliferation rate, admixed CD30‐positive large lymphoid cells, and few infiltrating CD8 positive T‐cells. The lymphoma cells were positive for CD3, CD4, CD2 and CD5, and negative for CD8. A subset of the lymphoma cells was positive for follicular helper T‐cell markers bcl‐6 and PD‐1. There were approximately 20% CD30‐positive large lymphoid cells, and Ki‐67 showed a moderately high proliferation rate (～40%), mostly in the large lymphoid cells. CD8 infiltrating T‐cells were few (<5%). The patient had an indolent disease with complete response to radiation therapy. To the best of our knowledge, this is the first reported case of SMPTCL with an increased proliferation rate and large CD30+ cells that followed an indolent clinical course.     

Primary cutaneous CD8+ cytotoxic T‐cell lymphoma involving the epidermis and subcutis in a young child

CD8+ cytotoxic T‐cell lymphoma involving the skin represents a heterogeneous group of diseases that include subcutaneous panniculitis‐like T‐cell lymphoma, primary cutaneous aggressive epidermotropic CD8+ cytotoxic T‐cell lymphoma, and ‘type D’ lymphomatoid papulosis. In this report, we describe a case of CD8+ cytotoxic T‐cell lymphoma involving both the epidermis and subcutis. The patient was a 6‐year‐old girl who presented with a 3‐year history of multiple plaques on her trunk and legs. The lesions had relapsed twice but responded well to prednisone. Histopathologic examination showed the proliferation of atypical lymphocytes in the epidermis, dermis and subcutaneous tissue. On immunohistochemical analysis, the atypical lymphocytes were positive for βF1, CD3, CD8, perforin, granzyme B and TIA‐1, but negative for T‐cell receptor (TCR) γ, CD4, CD30 and CD56. It was difficult to classify this tumor in terms of the known types of cutaneous lymphoma, and this case should be differentiated with subcutaneous panniculitis‐like T‐cell lymphoma and primary cutaneous aggressive epidermotropic CD8+ T‐cell lymphoma.     

Primary cutaneous follicle center lymphoma with Hodgkin and Reed‐Sternberg‐like cells: a new histopathologic variant

Primary cutaneous follicle center lymphoma (PCFCL) is the most frequent cutaneous B‐cell lymphoma. A 62‐year‐old man presented with a solitary indolent subcutaneous nodule for 3 years duration, without other abnormalities. Histological examination showed lymphoproliferation with a nodular growth pattern characterized by fibrous collagen bands surrounding nodules. The nodules were composed of medium‐sized centrocytes admixed with many large multilobulated and lacunar cells without eosinophils or granulomatous aspect. Hodgkin‐like cells were CD30+, CD15+, PAX5+, OCT2+, BOB1+, MUM1+, Ki67+, Bcl6+ and focally CD20+ and EMA?, CD79a?, Bcl2? and CD10?. The medium‐sized cells were CD20+, CD79a+, Bcl2+, Bcl6+ and CD10+, enmeshed in a network of CD21‐positive follicular dendritic cells. Epstein‐Barr virus detection was negative. Interphase fluorescence in situ hybridization showed the absence of BCL2 or BCL6 rearrangement. In such a case, the presence of Hodgkin‐like cells intermixed with the tumor population may result in a pitfall diagnosis of classical Hodgkin lymphoma (CHL). Differential diagnoses to be ruled out are secondary or primary skin localization of rather CHL, or systemic follicular lymphoma. Several clinical, radiological, histological, immunohistochemical and molecular arguments indicated the diagnosis of PCFCL. To our knowledge, this is the first report of PCFCL with Hodgkin‐like cells.     

Gamma‐delta T‐cell lymphoma arising in a long‐standing cutaneous plaque

The precise classification and characterization of primary cutaneous gamma‐delta T‐cell lymphoma (PCGD‐TCL) has been hindered by clinical and morphologic features that overlap with other lymphomas, especially subcutaneous panniculitis‐like T cell lymphoma (SPTCL). The recent World Health Organization/European Organization for Research and Treatment of Cancer (WHO/EORTC) classification distinguishes the more aggressive PCGD‐TCL from the usually indolent SPTCL, however. We report a 30‐year‐old woman with an indurated violaceous plaque on the left cheek that had been present for several years. Biopsies showed a dense lymphocytic infiltrate involving the subcutis and dermis that consisted mostly of small and medium‐sized lymphocytes, some with irregular nuclear contours and dense chromatin. These cells were positive for TIA‐1, TCR‐gamma and CD8, but negative for beta‐F1 and granzyme‐B. Staging with positron emission tomography–computed tomography (PET/CT), CBC and bone marrow with flow cytometry identified lymphadenopathy as well as blood and marrow involvement by an abnormal TCRgd‐positive T‐cell proliferation (Ann Arbor Stage IV). The patient's history of a long‐standing lesion in this case is unusual, in that gamma‐delta T‐cell lymphomas are typically rapidly progressive neoplasms. As such, it raises the possibility of ‘transformation’ of a long‐standing inflammatory process into an overt lymphoma.     

Immunophenotypic shift of CD4 and CD8 antigen expression in primary cutaneous T‐cell lymphomas: a clinicopathologic study of three cases

Primary cutaneous T‐cell lymphomas (CTCL) comprise a heterogeneous group of neoplasms with diverse clinical behavior. Mycosis fungoides (MF) is the most common type of CTCL. Immunophenotypical shift during progression of the disease is a rare event and its significance is unknown. We present three primary CTCL cases that showed an immunophenotypical shift and poor prognosis. Conventional hematoxylin/eosin and immunohistochemical‐stained sections were examined in all the cases. Molecular analysis for rearrangement of the T‐cell receptor (TCR) gene was performed in two cases. One case was classified as MF, while the other two lacked epidermotropism, and were considered primary cutaneous peripheral T‐cell lymphoma (PTCL), NOS. Two cases were CD3+/CD4+ and one case was CD3+/CD8+ at diagnosis. The first two patients suffered many relapses and eventually, new CTCL lesions with a CD3+/CD8+ phenotype were observed. Both cases revealed identical clonal TCR rearrangements on the initial and late lesions, supporting the interpretation of a single clonal proliferation with different phenotypes. The third case progressed with skin recurrences and pulmonary lesions with a predominant CD3+/CD4+/CD8? phenotype. All cases manifested poor prognosis and two patients died of lymphoma. Immunophenotypical shift between CD4 and CD8 in CTCL seems to be a rare phenomenon that may be associated with disease progression.     

Spindle‐cell variant of primary cutaneous follicle center lymphoma spreading to the hepatobiliary tree,mimicking Klatskin tumor

Primary cutaneous follicle center lymphoma (pcFCL) is an indolent type of primary cutaneous B‐cell lymphoma (pcBCL) rarely disseminating to other organs. PcBCL with spindle‐cell morphology has been described as a rare variant of pcFCL but the prognosis data of this variant is sparse. We report a rare case of spindle‐cell pcFCL with CD20⁺, CD79a⁺, CD3⁺, Bcl‐6⁺, Mum‐1^? and CD10^?tumor cells that infiltrated the hepatic hilum, mimicking a Klatskin tumor. On the basis of the sparse published data on spindle‐cell morphology of pcBCL, this growth pattern should elicit awareness of an increased risk of systemic involvement in the otherwise indolent pcFCL.     

Angioimmunoblastic T‐cell lymphoma with a clonal plasma cell proliferation that underwent immunoglobulin isotype switch in the skin,coinciding with cutaneous disease progression

Plasma cell proliferations in specific cutaneous lesions of angioimmunoblastic T‐cell lymphoma(AITL) are very uncommon. Here, we report a case of clonal plasma cell proliferation in skin with heavy‐chain‐immunoglobulin‐isotype‐switch after cutaneous disease progression. Histopathologically, initial plaque lesions were suggestive of marginal‐zone B‐cell‐lymphoma. Nevertheless, this 77‐year‐old lady was diagnosed with AITL after the progression of skin lesions from plaques to nodular tumors. A lymph node biopsy confirmed the diagnosis. Both cutaneous specimens showed a polymorphic cellular infiltrate with atypical T‐cell‐lymphocytes arranged in a pseudonodular pattern that expressed CD3, PD1 and BCL6, with patchy expression of CD30. Interestingly, a slight IgG‐Lambda plasma cell component was seen at the periphery of the infiltrate in the first specimen which increased in number in the later nodular lesion, showing not only Lambda light chain restriction and IgG but also IgG4. PCR studies for IgH and TCR genes showed an IgH clonal peak on both skin lesions but not on lymph node biopsy. On the contrary, the same clonal TCR peak was found in the three specimens. Neoplastic follicular helper T‐cells within cutaneous‐specific microenvironment could be responsible for the modulation of the immunoglobulin isotype class switch change. Further studies are needed to support this hypothesis.     

Non‐mycosis fungoides cutaneous T‐cell lymphoma: reclassification according to the WHO‐EORTC classification

Background: Non‐mycosis fungoides (non‐MF) primary cutaneous T‐cell lymphomas (PCTCL) are heterogeneous and divided into subgroups by the World Health Organization‐European Organization for Research and Treatment of Cancer (WHO‐EORTC) classification of cutaneous lymphomas. We report the first North American series to examine the applicability of the classification, compare our findings with the predominant European literature and confirm the significance of separation into the indolent and aggressive groups. Methods: Forty‐four non‐MF PCTCL cases with available tissue for phenotyping, adequate clinical staging information and follow‐up were reclassified according to the WHO‐EORTC classification. Results: Non‐MF PCTCL had a longer overall survival (OS) (13.8 years) compared with secondary cutaneous T‐cell lymphoma (SC‐TCL) (2.5 years). Primary cutaneous anaplastic large cell lymphoma (PC‐ALCL) had the most favorable outcome (OS 14.1 years), whereas secondary and primary peripheral T‐cell lymphoma, unspecified had the shortest OS (2.5 and 2.4 years, respectively). Primary cutaneous CD4+ small/medium‐sized pleomorphic T‐cell lymphoma (CTLCD4) appeared to have a favorable course. Conclusions: Most non‐MF PCTCL can be classified according to the WHO‐EORTC classification. The relative frequencies are similar to European experience. Non‐MF PCTCL is a heterogeneous group with a favorable outcome compared to SC‐TCL, especially PC‐ALCL and CTLCD4. Separation of non‐MF PCTCL into indolent and aggressive groups appears clinically significant and may provide direction for therapeutic decisions. Weaver J, Mahindra AK, Pohlman B, Jin T, His ED. Non‐mycosis fungoides cutaneous T‐cell lymphoma: reclassification according to the WHO‐EORTC classification.     

Chronic active Epstein–Barr virus infection with cutaneous and sinus lymphoproliferation in a white female patient with 25 years' follow‐up: an original case report

Chronic active Epstein–Barr virus infection (CAEBV) is characterized by chronic infectious mononucleosis‐like symptoms associated with very high viral load, as assessed by quantitative polymerase chain reaction. We present an unusual case in a French woman who was followed up over 25 years with cutaneous and sinus lymphoproliferation. This white woman presented with a long history of recurrent cutaneous necrotic papules of the skin, which started during childhood and healed spontaneously with depressed scars. The lesions spread to the left maxillary sinus and were associated with hepatomegaly and splenomegaly with no other visceral locations. Pathological examination of the skin and sinus revealed a dermal monoclonal T‐cell lymphoproliferative disorder, CD7⁺ and CD20^?, with no epidermotropism. T‐cell receptor rearrangement was positive, showing the monoclonality from the first biopsy. This T‐cell proliferation was positive for EBV‐encoded small RNA and was associated with a high EBV viral load. Since then, the patient has been in good health, despite a permanently high EBV viral load. Hydroa vacciniforme (HV)‐like lymphoma and natural killer/T‐cell lymphoma were discussed, but none really fit our case. Natural killer cell lymphoma was ruled out because of the indolent course, but sinus lesions do not exist in HV‐like lymphoma. A therapeutic approach is difficult because of the coexistence of viral infection and monoclonal T‐cell proliferation. Chemotherapy is not efficient and induces immunosuppression, which may worsen the prognosis. Although rituximab may have an immunomodulatory function, it was not effective in our case.     

Pruritic arthropod bite‐like papules in T‐cell large granular lymphocytic leukaemia and chronic myelomonocytic leukaemia

T‐cell large granular lymphocytic leukaemia (T‐LGLL) is a clinically indolent mature T‐cell neoplasm characterized by a monoclonal population of CD3+ CD8+ cytotoxic T cells, which usually presents as neutropenia, anaemia and thrombocytopenia. Chronic myelomonocytic leukaemia (CMML) is a clonal haematopoietic disorder with features of both a myeloproliferative neoplasm and myelodysplastic syndrome (MDS). Patients with CMML exhibit a persistent peripheral blood monocytosis in addition to myelodysplastic features. Because of the rarity of T‐LGLL, its cutaneous manifestations are poorly documented, but include vasculitis, vasculopathy, persistent ulcerations, generalized pruritus and disseminated granuloma annulare. Various types of skin lesions have been observed in patients with CMML and reportedly occur in approximately 10% of cases. We report the extraordinary case of a patient with MDS who developed T‐LGLL, and subsequently the MDS progressed to CMML. The patient then developed diffuse arthropod bite‐like papules and intractable pruritus.     

Cutaneous atypical papular CD8+ lymphoproliferative disorder at acral sites in a renal transplant patient

A 20‐year‐old woman presented with a 2‐month history of an acute symmetrical eruption, manifesting as asymptomatic ill‐defined erythematous macules and hyperkeratotic papules on the palms. The patient was a renal transplant recipient, and the lesions had developed 2 months post‐transplantation. Histologically, the eruption shared features of a reactive inflammatory condition called papular eruption of atypical CD8+ lymphocytes as well as primary cutaneous acral CD8+ T‐cell lymphoma (a provisional indolent entity in the new World Health Organisation classification of lymphoid neoplasms, 2016). The latter disorder has been described to occur at acral sites in immunocompetent patients, whereas the former has previously been described only in patients infected with human immunodeficiency virus. The lesions in our patient healed after topical treatment with corticosteroids and alteration of immunosuppressive therapy, supporting the role of immunosuppression in this case. We classified our patient's condition as lying in the spectrum of the aforementioned two conditions, but the relationship between both diseases remains to be clarified. Awareness of these unusual conditions may prevent the use of unnecessary aggressive therapies in similar patients.