Indolent CD8+ lymphoid proliferation of the ear: report of two cases and review of the literature

Homozygous Loss of CDKN2 in Primary Cutaneous CD8(+) Lymphoma NOS

ABSTRACT

Primary cutaneous acral CD8(+) lymphoma (AL) has been accepted as primary cutaneous acral CD8-positive T-cell lymphoproliferative disorder in the revised WHO and updated WHO-EORTC lymphoma classifications. Commonly arising on the ears and comprising a clonal cytotoxic CD8 + T-cell infiltrate, almost all cases follow an indolent clinical course. A single aggressive case reported in the literature had a deletion at the CDKN2 locus at 9p21. We report an atypical CD8 + T-cell proliferation arising on the chest of an elderly man who had some similarities to AL but with a very high proliferation rate, absent p16 protein expression, and homozygous loss of the CDKN2 locus using FISH analysis. A diagnosis of peripheral T-cell lymphoma not otherwise specified (PTCL NOS) was preferred. Analyses of 4 cases of AL demonstrated often low p16 protein expression but intact CDKN2 loci. This case raises the problems of the boundaries between AL and PTCL NOS, and a possible role in the loss of p16 function in pathogenesis.

Unusual presentation for small lymphocytic lymphoma: Case report of a man with bilateral ear involvement and review of the literature

INTRODUCTION

Ear involvement by non-Hodgkin lymphoma is quite rare and can be mistaken for other common lesions encountered in otolaryngology. The literature on this subject is also limited.

CASE SUMMARY

A 45-year-old man with bilateral ear nodules that progressed over two years. Biopsy of the right ear revealed a B-cell small lymphocytic lymphoma (SLL). The patient responded to radiotherapy well. He received an additional dose two months after the initial treatment because of a remaining nodularity on the right earlobe. After several months, he presented a new lesion on his nasal tip, for which a biopsy confirmed a lymphoma relapse. The patient was managed with oral prednisone and low-dose radiation with a favourable response.

DISCUSSION

This case highlights the importance of including lymphoma in the differential diagnosis of ear lesions from an otolaryngology perspective. A biopsy of any lesion or nodule with an atypical course should be considered for appropriate diagnosis and management.

Rare T-Cell Subtypes

There are a number of rare T-cell lymphoma subtypes that may be encountered in clinical practice. In recent years, improved immunohistochemical techniques and molecular tumor profiling have permitted refinement of some of the diagnostic categories in this group, as well as the recognition of distinct conditions not previously well elucidated. In this chapter, we cover the diagnostic and clinical features of some of the more common of these conditions, including subcutaneous panniculitis-like T-cell lymphoma, cutaneous gamma-delta T-cell lymphoma, enteropathy-associated T-cell lymphoma, monomorphic epitheliotropic intestinal T-cell lymphoma, primary cutaneous CD8-positive aggressive epidermotropic cytotoxic T-cell lymphoma, CD4-positive small/medium T-cell lymphoproliferative disorder, and acral CD8-positive T-cell lymphoma. Given the rarity of these conditions, optimal treatments approaches are not always well established, not least as data from large-scale clinical trials are lacking. In this chapter, we aim to provide a summation of current thinking around best treatment, as well as highlighting some controversies in the management of these diagnoses.

A Case of an Indolent CD8-Positive Lymphoid Proliferation of the Ear

A lady presented with indolent slowly spreading erythematous nodule on the left external ear which on histopathology showed dense monomorphic lymphoid cells in the dermis. No epidermotropism or angioinvasion was seen. Immunohistochemistry showed that the infiltrating lymphoid cells were CD8+ but CD4-. Majority of the cases of cutaneous T-cell lymphomas have a CD4+, CD8− T-cell expression. Few cases have been reported with similar CD8-positive lymphoid proliferation with a curious ear tropism.

Primary Cutaneous Acral CD8+ T-Cell Lymphoma

Primary cutaneous acral CD8+ T-cell lymphoma is a new provisional entity in the 2016 revision of the World Health Organization classification of lymphoid neoplasms. This is a challenging diagnosis because of its rarity, as well as its morphologic and immunophenotypic overlap with other CD8+ cytotoxic lymphoid proliferations. Appropriate classification of this entity is crucial because of its indolent clinical behavior compared with other CD8+ T-cell lymphomas. Knowledge of the clinical setting, sites of involvement, and morphologic features can aid in correct diagnosis. Here, we review the clinical and pathologic features of primary cutaneous acral CD8+ T-cell lymphoma with an emphasis on the differential diagnosis among other C8+ T-cell lymphomas.

Managing Patients with Cutaneous B-Cell and T-Cell Lymphomas Other Than Mycosis Fungoides

Cutaneous lymphomas (CL) are a heterogeneous group of neoplasms characterized with clinical and histopathological variation, as well as overlap with benign dermatoses. Diagnosis and treatment of CLs is challenging and often requires a multidisciplinary approach. However, prognostic knowledge of these conditions and awareness of treatment options can help optimize appropriate use of available regimens, thereby improving care for patients. Here, we review the most recent literature and outline treatment themes for managing patients with cutaneous B-cell and T-cell lymphomas other than mycosis fungoides.

Primary cutaneous acral CD8 positive T-cell lymphoma with extra-cutaneous involvement: A long-standing case with an unexpected progression

Primary cutaneous acral CD8+ T-cell lymphoma (acral CD8+ TCL) is a new provisional entity characterized by acral skin lesions and an indolent course. We describe an extraordinary case characterized by relapsed nodules with CD8+ cytotoxic infiltrates on the left ear. After 35 years, the skin lesions spread to other acral sites, and a mass with the same histological features as the other skin lesions appeared on the nose. Multiple courses of chemotherapy led to stable disease. Histological examinations carried out at different times showed the gradual transformation of the neoplastic cells, with an increased proliferation index. Genomic analysis revealed losses in the regions harboring the genes involved in cell cycle control. This is the first case of an acral CD8+ TCL with a very long history of indolent nodular lesions progressing to extra-cutaneous sites.

Long-term follow-up and management of small and medium-sized CD4+ T cell lymphoma and CD8+ lymphoid proliferations of acral sites: a multicenter experience

BACKGROUND

Primary cutaneous CD4⁺ small-medium pleomorphic T cell lymphoma (SMPTCL) is a low-grade cutaneous T cell lymphoma. Its clinical and histopathologic features are comparable with those of CD8⁺ lymphoid proliferations (LPs) of the ear and acral sites.

OBJECTIVES

We performed a retrospective analysis of patients with CD4⁺ SMPTCL or CD8⁺ LP to elucidate the clinical course, prognosis, and outcomes.

METHODS

Demographic, clinical, and treatment data were reviewed. Histopathologic data based on architectural, cytomorphologic, and immunohistochemical features were assessed. Immunohistochemical staining for T and B cell markers was evaluated.

RESULTS

A total of 25 patients including 22 with CD4⁺ SMPTCL and three with CD8⁺ LP were identified. All patients presented with a single lesion, predominantly on the head, neck, or upper trunk (84%). No patients showed extracutaneous disease at any evaluation. The most common histopathologic changes showed a dense nodular infiltrate of small cells with hyperchromatic nuclei without significant follicular or adnexal involvement. Patients were treated with excision (48%), local radiation (28%), or topical or intralesional steroids (24%). All patients achieved complete resolution of disease. Five patients demonstrated cutaneous relapse at new sites.

CONCLUSIONS

The CD4⁺ SMPTCL/CD8⁺ LP subgroup usually presents with solitary lesions and demonstrates an indolent clinical course. Typical presentation, classic histopathology, widespread expression of follicular T helper cell markers, and loss of a T cell antigen are diagnostic features of CD4⁺ SMPTCL, whereas monomorphous CD8⁺ infiltrate without follicular T helper cell markers is consistent with CD8⁺ LP. Local skin-directed therapy is appropriate in these patients.

Cutaneous Lymphomas with Cytotoxic Phenotype

Primary cutaneous cytotoxic lymphomas are T-cell or natural killer-cell lymphomas that express 1 or more cytotoxic markers. These neoplasms constitute a spectrum of diseases. In this review, an overview of clinical, morphologic, and phenotypical features of each subtype is provided. Differential diagnosis is discussed with attention to scenarios in which diagnostic difficulties are most frequently encountered.

Uncommon Variants of T-Cell Lymphomas

Peripheral T-cell lymphomas represent 10% to 15% of non-Hodgkin lymphomas and comprise more than 20 different entities. Treatment of very rare T-cell lymphomas can be challenging because there are no large or randomized studies to guide clinical decision making, and treatment paradigms are often based on small series or imperfect data. Although a strict algorithm cannot be written with certainty, through the literature that exists and clinical experience, themes and principles of approaches do emerge that when coupled with clinical judgment allow reasonable and logical decisions.

Approach to Cutaneous Lymphoid Infiltrates: When to Consider Lymphoma?

Cutaneous lymphoid infiltrates (CLIs) are common in routine dermatopathology. However, differentiating a reactive CLI from a malignant lymphocytic infiltrate is often a significant challenge since many inflammatory dermatoses can clinically and/or histopathologically mimic cutaneous lymphomas, coined pseudolymphomas. We conducted a literature review from 1966 to July 1, 2015, at PubMed.gov using the search terms: Cutaneous lymphoma, cutaneous pseudolymphoma, cutaneous lymphoid hyperplasia, simulants/mimics/imitators of cutaneous lymphomas, and cutaneous lymphoid infiltrates. The diagnostic approach to CLIs and the most common differential imitators of lymphoma is discussed herein based on six predominant morphologic and immunophenotypic, histopathologic patterns: (1) Superficial dermal T-cell infiltrates (2) superficial and deep dermal perivascular and/or nodular natural killer/T-cell infiltrates (3) pan-dermal diffuse T-cell infiltrates (4) panniculitic T-cell infiltrates (5) small cell predominant B-cell infiltrates, and (6) large-cell predominant B-cell infiltrates. Since no single histopathological feature is sufficient to discern between a benign and a malignant CLI, the overall balance of clinical, histopathological, immunophenotypic, and molecular features should be considered carefully to establish a diagnosis. Despite advances in ancillary studies such as immunohistochemistry and molecular clonality, these studies often display specificity and sensitivity limitations. Therefore, proper clinicopathological correlation still remains the gold standard for the precise diagnosis of CLIs.

Multicenter case series of indolent small/medium-sized CD8+ lymphoid proliferations with predilection for the ear and face

We report 7 cases of a CD8 lymphoid proliferation of the ear and face with a cytotoxic T-cell phenotype, but an indolent clinical course. All patients presented with stable or slowly growing asymptomatic lesions on the ear, nose, or lower eyelid. Histopathology showed a dense diffuse dermal infiltrate of small- to medium-sized atypical lymphocytes without destructive features. The lymphocytes were positive for CD3, CD8, β-F1, and TIA-1 and negative for CD4, CD30, CD56, granzyme B, and PD-1. Of note, the proliferation index was low in available cases. All patients remained in complete remission at median follow-up of 14 months regardless of treatment modality. Staging was negative for extracutaneous disease in all patients. The clinically indolent behavior and histopathologic phenotype together with a low proliferation index (10%-15%) emphasize the importance of accurate diagnosis and appropriate clinical management to avoid overtreatment and complications of therapy.

Cytotoxic T-cell and NK-cell lymphomas: current questions and controversies

The cytotoxic T-cell and natural killer (NK)-cell lymphomas and related disorders are important but relatively rare lymphoid neoplasms that frequently are a challenge for practicing pathologists. This selective review, based on a meeting of the International Lymphoma Study Group, briefly reviews T-cell and NK-cell development and addresses questions related to the importance of precise cell lineage (αβ-type T cell, γδ T cell, or NK cell), the implications of Epstein-Barr virus infection, the significance of anatomic location including nodal disease, and the question of further categorization of enteropathy-associated T-cell lymphomas. Finally, developments subsequent to the 2008 World Health Organization Classification, including the recognition of indolent NK-cell and T-cell disorders of the gastrointestinal tract are presented.

Indolent CD8+ lymphoid proliferation of the face with eyelid involvement

In 2007, Petrella et al described a series of patients with clonally restricted, well-differentiated, nonepidermotropic, CD8-dominant lymphocytic infiltrates localized to the facial area. The clinical course described was indolent. A CD8 variant of primary cutaneous pleomorphic T-cell lymphoma has been proposed; however, there are many dissimilar features. The authors encountered 2 patients with CD8⁺ indolent lymphoid proliferation of the face, localized to the eyelid. Both patients were males in their 30s presenting with localized lesions of the eyelids. The biopsies showed an effacing lymphocytic infiltrate that spanned the sampled dermis. The lymphocytes were well differentiated, exhibiting mild nuclear contour irregularity. The infiltrate was predominated by CD8⁺ lymphocytes demonstrating TIA expression. There was a minimal B-cell component in 1 case, whereas another showed a significant degree of B-cell hyperplasia. They both underwent complete excision without recurrence. CD8⁺ indolent lymphoid proliferation has a reproducible clinical and morphologic presentation that warrants categorization as a distinct form of indolent lymphoproliferative disease, preferentially involving older adults with the most common site being the ear, recognizing that the nose, acral surfaces, and eyelids can also be involved.

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.

[Indolent lymphoma of the ear]

INTRODUCTION

In 2007, Petrella et al. identified a new entity: CD8 T-cell indolent lymphoma of the ear.

CASE REPORT

A 40-year-old man presented a nodular erythematous and violaceous painless lesion on his right ear that had appeared four months earlier. Excision histology revealed a non-epidermotropic T-cell proliferation infiltrating the entire dermis and subcutis but with sparing of a grenz zone. The monotonous infiltrate was positive for CD8, CD3, CD5 and TIA-1, and negative for CD30, CD4, CD56, ALK and EMA. The Mib1 proliferation index was 20%. Lyme serology and PCR for EBV were negative. Additional examinations showed no extracutaneous involvement.

DISCUSSION

CD8+ indolent lymphoma is an entity first described in 2007 and reported in the literature in 15 patients. Lesions are located on the nose or external ear. It comprises a non-epidermotropic proliferation of CD8+ T lymphocytes negative for CD4, CD30, CD56, CD57, granzyme B and perforin. The Mib1 proliferation index is low. This new entity appears neither in the 2005 World Health Organization/European Organization for Research and Treatment of Cancer (WHO/EORTC) classification of cutaneous lymphomas nor in the WHO 2008 Classification of tumours of haematopoietic and lymphoid tissues. Surgical treatment or radiotherapy is sufficient, and unlike aggressive, epidermotropic CD8+ T lymphomas chemotherapy is not required.

[Indolent CD8+ lymphoid proliferation on the nose]

BACKGROUND

Indolent non-epidermotropic CD8+ lymphoid proliferation of the ear was recently reported in the literature by Petrella et al. This is a distinct entity related to cutaneous T-cell lymphomas. Herein, we report a case of indolent CD8+ lymphoid proliferation of the ear involving the nasal crest and we relate a number of cases recently published in the literature.

PATIENTS AND METHODS

An 87-year-old woman consulted for a pigmented papular lesion of the nasal crest present for 9 years that had begun to regress spontaneously. The remainder of the examination revealed nothing of note. The biopsy showed dense lymphoid infiltration within the dermis. Immunohistochemical analysis supported the diagnosis of indolent CD8+ lymphoid proliferation. Treatment with moderate topical corticosteroids was initiated.

DISCUSSION

This novel entity is characterised by the presence of relatively non-symptomatic infiltrated lesions in the ear, which can occur bilaterally. Histological findings are frequently worrying with the presence of a dense cellular infiltrate comprising a relatively monomorphous population of CD8+ lymphocytes, although progression is usually indolent.

Indolent CD8-positive T-cell lymphoid proliferation of the ear: a report of two cases

The current classification of primary cutaneous T-cell lymphoma (CTCL) of the World Health Organization (WHO) includes primary cutaneous CD8-positive aggressive epidermotropic cytotoxic T-cell lymphoma as a provisional entity awaiting cumulative data. Recent reports identify CD3/CD8-positive clonal T-cell lymphoid proliferations arising in the ear and nose that behave indolently and therefore defy currently established subclassification. Here, we report two cases of clonal CD8-positive/granzyme-B-negative T-cell lymphoid proliferations that arose in the ear and behaved indolently. Collectively, these cases suggest that an additional category of cutaneous indolent CD8-positive T-cell lymphoma may be necessary among the existing classification schemes.

Comments on cutaneous lymphomas: since the WHO-2008 classification to present

The last classification of lymphomas of the World Health Organization in 2008 made a few changes from the preceding classification. Although useful, at the same time, it has posed new questions, concerns, and dilemmas which have been raised in the literature. The current report highlights some of these controversies, of each of these primary cutaneous entities, going through cutaneous mature T-cell and NK-cell neoplasms, mature B-cell neoplasms, precursor neoplasms, and other entities, which for several reasons do not fit in the previous categories. It also reviews some advances on many of these lymphomas published in the last 2 years.