Lymphocytic Exocytosis Research Articles

Erythema multiforme minor in a dog following inappropriate intranasal Bordetella bronchiseptica vaccination: a case report

A one-year-old, intact female, Yorkshire terrier dog was presented with a six-month history of multifocal, polycyclic erythematous lesions with epidermal collarette formation at the axillae, the trunk and ventral abdomen. The dog had a history of an inappropriate vaccine administration one day prior to the onset of clinical signs. The histopathology of the lesions revealed apoptosis of keratinocytes in the overlying epidermis, hydropic degeneration and lymphocytic exocytosis. The clinical signs and histopathology of the lesions were compatible with erythema multiforme. The skin lesions resolved after treatment with prednisolone combined with azathioprine for one month. No recurrence of clinical signs occurred during the follow-up period (four months). This is the first case report of erythema multiforme associated with an accidental subcutaneous injection of a Bordetella bronchiseptica vaccine.  

Recurrent Gianotti-Crosti syndrome

To the Editor: Gianotti-Crosti syndrome (GCS) classically presents in children as a self-limited, symmetric erythematous papular eruption affecting the cheeks, extremities, and buttocks. While initial reports implicated hepatitis B virus as the etiologic agent, many other bacterial, viral, and vaccine triggers have since been described. A previously healthy 2-year-old boy presented with a 3-week history of a cutaneous eruption that initially appeared on his legs and subsequently progressed to affect his arms and face. Two weeks after onset of the eruption, he was immunized with intramuscular Vaxigrip influenza vaccination (Sanofi Pasteur), and new lesions appeared at the immunization site on his right upper arm. Physical examination demonstrated an afebrile child with erythematous papules on the cheeks, arms, and legs (Fig 1). He had a localized papular eruption on his right upper arm (Fig 2). There was no lymphadenopathy or hepatosplenomegaly. Laboratory investigations revealed leukocytosis (white cell count, 14,600/mm) with a normal differential, reactive thrombocytosis ( platelet count, 1,032,000/mm), a positive urine culture for cytomegalovirus, and positive IgM serology for Epstein-Barr virus (EBV). Histopathologic examination of a skin biopsy specimen from the right buttock revealed a perivascular and somewhat interstitial lymphocytic infiltrate in the superficial and mid-dermis with intraepidermal exocytosis of lymphocytes, mild spongiosis and papillary dermal edema. He was treated with 2.5% hydrocortisone cream, and the eruption resolved. Twelve months later, he presented with a similar papular eruption localized to the left upper arm at the site of a recent intramuscular influenza vaccination (Vaxigrip). Although an infection represents the most important etiologic agent, a second event involving immunomodulation might lead to further disease accentuation, thus explaining the association of GCS with vaccinations. In our case, there was evidence of both cytomegalovirus (CMV) and EBV infection as well as a recent history of immunization. Localized accentuation of papules at the immunization site was unusual, as previous cases of GCS following immunizations have had a widespread and typically symmetric eruption. It is possible that trauma from the injection or a component of the vaccine elicited a Koebner response, causing local accentuation. There are no previous reports of recurrence of vaccine-associated GCS. One report documented recurrence with two different infectious triggers. As GCS is a mild and selflimiting disease, further vaccinations are not contraindicated. Andrei I. Metelitsa, MD, FRCPC, and Loretta Fiorillo, MD, FRCPC

Canine parvovirus-2b–associated erythema multiforme in a litter of English Setter dogs

Erythema multiforme (EM) was diagnosed in a litter of English Setter puppies. The puppies developed erythematous cutaneous lesions at the age of 2 weeks. Microscopically, there was individual keratinocyte apoptosis associated with lymphocyte exocytosis in all layers of the epidermis. Intranuclear viral inclusions were seen in multiple tissues and organs. Tissues from the tongue, lymph node, spleen, skin, and small intestine were positive for Canine parvovirus-2 (CPV-2) and negative for Canine distemper virus (CDV) and Canid herpesvirus 1 by fluorescent antibody test. Negative-staining electron microscopy detected parvovirus particles in the intestinal contents. The skin and small intestine were positive for CPV-2b and negative for CDV by polymerase chain reaction. The mucocutaneous junctions and small intestines stained positive for CPV by immunohistochemistry. The present report documents CPV-2b-associated EM in a litter of English Setters and substantiates the single previous report associating EM with CPV-2. The finding suggests that CPV should be considered as a possible cause of EM in dogs.

Diagnostic Exercise: Severe Bilaterally Symmetrical Alopecia in a Horse

A 9-year-old Tennessee Walking Horse gelding was presented for diagnosis of the cause of extensive alopecia. Complete hair loss was noted over the head, neck, shoulder, thigh, and proximal limbs, but the trunk, distal limbs, pelvic area, mane, and tail were unaffected. The alopecic areas were visually noninflammatory with no exudate or crust except on the shoulder and along the back, where multifocal patchy areas of alopecia with scales and crust were evident. The horse was slightly pruritic. Microscopically, the hair bulbs, inner and outer root sheaths of inferior segments, and perifollicular regions were infiltrated by small to moderate numbers of small lymphocytes. Similar inflammation was occasionally evident in isthmus follicular walls as well as some apocrine glands. No sebaceous glands were affected. Immunohistochemistry confirmed that the small lymphocytes were CD3(+) T lymphocytes. The epidermis from the skin with scale and crusts along the horse's back exhibited mild to moderate hyperplasia, mild lymphocytic exocytosis, mild eosinophilic dermatitis, and diffuse parakeratosis with numerous budding yeasts, consistent with Malassezia spp. The final disease diagnosis was made as alopecia areata with Malassezia dermatitis. Alopecia areata could be a contributing underlying factor for Malassezia dermatitis.

Pruritic brownish confluent reticulated papules over the trunk of a 30-year-old woman

Conflict of interest: none declared. A 30‐year‐old woman presented with a 13‐year history of a pruritic erythematous maculopapular eruption distributed symmetrically over the chest, back and posterior neck. Recurring bouts of pruritic papules had left striking reticular hyperpigmented patches on the affected areas (Fig. 1). ... A skin biopsy was taken from an erythematous papule surrounded by hyperpigmented macules on the upper back. Histological examination under low magnification showed acanthosis and a superficial perivascular infiltration of inflammatory cells, and under higher magnification, spongiosis, lymphocytic exocytosis and vacuolar degeneration of the basal cell layer was seen (Fig. 2). ... What is your diagnosis? Prurigo pigmentosa (PP), late stage. PP is a rare inflammatory dermatosis of unknown aetiology. It was first reported in Japan, where it is found most commonly; it is rare in western countries. The clinical features are symmetrical and intensely pruritic erythematous papules, papulovesicles and vesicles appearing in a reticular pattern with a predilection for the upper part of the back, neck, shoulders, lumbosacral region and abdomen. The lesions involute in a matter of days, leaving reticulate pigmentation.1

Lupus erythematosus with exclusive involvement of the acrosyringia

Cutaneous lesions of lupus erythematosus (LE) show a broad spectrum of clinicopathologic features. Histopathologically, besides typical patterns such as interface dermatitis, perivascular lymphocytic infiltrate and dermal mucin deposits, an involvement of the eccrine structures, especially the acrosyringium, may be observed. We describe the case of a 21-year-old woman with a 4-year history of systemic LE, who presented with a 'butterfly' rash over the cheeks as well as erythematous macules on the arms and décolleté. Biopsy from one lesion on the arm revealed interface changes, necrotic keratinocytes and exocytosis of lymphocytes restricted only to the regions of the acrosyringia. The epidermis between affected acrosyringia was normal with no hints of interface dermatitis. The eccrine glands and coils were not affected. In the dermis there were only sparse inflammatory infiltrates. Differential diagnoses such as erythema multiforme, drug eruption and lichen planus could be ruled out because of histopathologic features and clinical presentation. This is an example of a peculiar histopathological variant of cutaneous LE, characterized by exclusive involvement of the acrosyringia. The histopathologic features represent a pitfall in the diagnosis and can be correctly interpreted only upon correlation with clinical data.

A study of clinicohistopathological correlation in patients of psoriasis and psoriasiform dermatitis

Psoriasis has different clinical variants, which mimic diverse dermatological conditions and may require a histopathological confirmation of the diagnosis. Studies to establish a clinicohistopathological concordance (and its determinants), in psoriasis and psoriasiform dermatitis are lacking. The present study was designed (a) to correlate the clinicohistopathological features of psoriasis and psoriasiform dermatitis, and (b) to identify determinant(s) that may contribute to the diagnosis of psoriasis and psoriasiform dermatitis. This was a prospective study involving 100 patients, with a single clinical diagnosis of psoriasis or with psoriasis as one of the differential diagnoses, and its correlation with histopathological features. The clinical features of typical scale (P = 0.0001) and Auspitz's sign (P = 0.0001), and histological evidence of suprapapillary thinning (P = 0.0001) and absent granular cell layer (P = 0.0001) were found to be statistically significant contributors to the clinicohistological concordance in cases of psoriasis. Vertical orientation of collagen bundles (P = 0.0001) and lymphocytic exocytosis (P = 0.003) were found to be significantly associated with diagnosis of psoriasiform dermatitis. The present study reconfirms the diagnostic accuracy of silvery white scale, Auspitz's sign, and Koebner's phenomenon in a clinical setting suggestive of psoriasis. However, in their absence, histological evidence of suprapapillary thinning and absent granular layer, in addition to the Munro microabscess and Kogoj's abscess, may contribute to the diagnosis of psoriasis. Similarly, vertical orientation of collagen bundles and lymphocytic exocytosis may point toward a diagnosis of psoriasiform dermatitis.

A case of adult blaschkitis with features of interface dermatitis

Conflicts of interest: none declared. Sir, Adult blaschkitis is a rare, relapsing linear eruption of pruritic papules and vesicles. The lesions involve multiple sites, particularly the trunk, and follow Blaschko’s lines.1 2–3 Blaschkite de l’adulte and acquired relapsing self‐healing Blaschko dermatitis have been suggested as alternative names for this condition.1, 2 Seven cases have been reported in the literature since it was first described in 1990 by Grosshans and Marot, and the histopathological findings were those of spongiotic dermatitis.1 2–3 We present a case of adult blaschkitis with the histopathological features of interface dermatitis. A 31‐year‐old man presented with a 1‐month history of unilateral pruritic skin disease. He had no history of atopic dermatitis, psoriasis, or any other dermatitis. He had no significant past medical or drug use history. Physical examination revealed discrete erythematous grouped papules and vesicles on the left sides of the trunk and upper and lower limbs. The skin lesions formed whorls and streaks along Blaschko’s lines (Fig. 1). A punch biopsy from an abdominal lesion revealed hyperkeratosis, focal parakeratosis, acanthosis, and scattered dyskeratotic cells with basal cell vacuolar degeneration in the epidermis. Spongiosis and lymphocyte exocytosis were also found. Superficial perivascular lymphocytic infiltrates were seen in the dermis (Fig. 2). A short course of oral corticosteroids (20 mg daily) and topical corticosteroid lotion were prescribed. The existing skin lesions improved; however, new lesions developed. His skin lesions cleared with the addition of narrowband ultraviolet B phototherapy (total 6250 mJ, twice a week for 2 months).

Syndrome des vestibulites vulvaires : étude anatomoclinique de 14 cas

Vulvar vestibulitis syndrome (VVS) is one of the most frequent causes of superficial dyspareunia in young women. VVS has a pronounced psychological impact. The results of pathological studies published thus far are controversial. Fourteen women with VVS were included in this study and underwent vestibular biopsy. Vulvar biopsies were taken from the orifice of Bartholin's gland. The biopsy samples were stained with a standard stain and PAS and 25 serial sections were prepared for each specimen. The mean patient age was 26 years and VVS had been present for a mean 30 months. Extensive inflammation of mononuclear cells was observed in the vulvar chorionic epithelium. This inflammation was seen mainly around the minor vestibular glands. Mild exocytosis of lymphocytes was noted in the vestibular glands and ducts. Most studies concerning this disease report chronic inflammation of the vulvar vestibular mucosa. This inflammation is seen mainly around the minor vestibular glands. We report the same pattern in our study. Moreover, we observed some exocytosis into the epithelium of minor vestibular glands and the excretory duct. This aspect has not been reported to date, further supporting the individual nature of this entity.

Symmetrical onychomadesis in Norwegian Gordon and English setters

This study reports the condition onychomadesis affecting multiple claws in Norwegian Gordon and English setters. Medical records of and claw biopsies from 18 Gordon and four English setters with onychomadesis of multiple claws were obtained from July 2005 to January 2007. Only dogs with symmetrical onychomadesis and no signs of concurrent disease were included. Histopathological features varied between dogs, but typically included interface dermatitis with subepidermal cleft formation, pigment incontinence, basal cell vacuolization and necrosis, spongiosis and lymphocytic exocytosis, a lymphocytic, plasmacytic subepidermal inflammation, and fibroplasia. In two dogs, histopathological signs of a superficial infection were present. The age of onset of disease varied between 2 and 7 years with a mean of 3.9 years, and was not correlated with vaccination time. Six of the affected dogs also had siblings with the disease. Due to the close relationship of the affected dogs, pedigree map analysis was not possible. Three dogs were euthanized because of the disease and two had regrowth of normal claws. Seventeen dogs had persistent onychodystrophy that typically was nonpainful during therapy which in most dogs consisted of fatty acid supplementation or prednisolone.

Perforating lichenoid reaction to amlodipine

We report here the case of a 54 year-old woman on amlodipine 5 mg for the past six years for systemic hypertension who presented with intensely pruritic, hyperpigmented, keratotic, lichenoid papules topped with white scales over her upper and lower limbs since the last seven months (Fig. 1). The trunk was also involved with less severity. The oral and genital mucosal tissues were normal. She was not on any other medication. Routine investigations including that for blood sugar were within normal limits. Fig. 1 Hyperkeratotic, pigmented, lichenoid papules over the lower limbs Clinically, transepidermal elimination (TEE) disorder and lichen planus are considered as differential diagnosis. These two conditions were considered as differential diagnostic possibilities. Histological examination showed a lichenoid reaction with transepidermal elimination of collagen (Figs. ​(Figs.22 and ​and33). Fig. 2 Epidermis shows focal parakeratosis, basal vacuolar damage, lymphocytic exocytosis. Extension of eosinophilic material admixed with polymorphs is seen over the area adjacent to the site of perforation (H and E, ×100) Fig. 3 Transepidermal elimination of collagen fibers (Verhoeff van Gieson elastic stained, ×400) The patient was treated with potent topical corticosteroids, injection triamcinolone acetonide 40 mg/ml IM stat and amlodipine was replaced with losartan 50 mg daily. One month later, all the lesions had subsided leaving postinflammatory hyperpigmentation. The marked symptomatic and clinical improvement following the withdrawal of amlodipine implicates the drug as the most likely cause of the lichenoid papules. Rechallenge with amlodipine was not acceptable to the patient. Various reactions have been reported with amlodipine including generalized pruritus, erythematous rash, ecchymosis, purpura, urticaria and photosensitivity presenting as telengiectasia.1,2 Lichenoid reactions may develop after weeks or months following the initiation of therapy.3 Although lichen planus has been linked to calcium channel blockers, there are very few reports of amlodipine-associated lichen planus.4 Transepidermal elimination with perforation is very rarely seen in classical lichen planus cases.5 This finding has not been reported in associaton with lichenoid reactions. A perforating lichenoid reaction could represent a rare, unlisted reaction to amlodipine.

No differences in caspase‐3 and Bax expression in atrophic‐erosive vs. reticular oral lichen planus

Caspase-3 (CPP32) and Bax expression levels in oral lichen planus (OLP) lesions are considered reliable markers of apoptosis. The malignant transformation of OLP remains a very controversial matter. The objective of this study was to compare histological and apoptotic phenomena between atrophic-erosive and reticular forms of OLP. Analysis was conducted of biopsy samples from 18 patients with reticular and 14 with atrophic-erosive OLP. Conventional histology techniques were used to quantify histological markers of OLP and peroxidase/anti-peroxidase techniques to determine apoptosis markers caspase-3 (CPP32) and Bax. More Civatte bodies and lymphocyte exocytosis were observed in atrophic-erosive than reticular OLP samples, without any statistical difference. No statistical significant differences in caspase-3 expression were found between these OLP forms in suprabasal layer (58.3% vs. 43.8%), basal layer (83.3% vs. 68.8%) or infiltrate (69.2% vs. 46.6%). Bax expression was relatively infrequent, and no differences were observed between atrophic-erosive and reticular forms. The low frequency of apoptotic phenomena (caspase-3 and Bax) in epithelial cells of OLP may create a favourable substrate for malignant transformation. However, there does not seem to be an association with the clinical form (atrophic-erosive or reticular).

Alopecia syphilitica with detection of Treponema pallidum in the hair follicle

Alopecia is one of the clinical manifestations of secondary syphilis. It is uncommon for hair loss to be the sole or predominant manifestation, as hair loss is the chief clinical and histologic differential diagnosis of alopecia areata. The main difference between these two entities is the detection of Treponema pallidum in syphilis. We present the case of a 24-year-old Hispanic man, human immunodeficiency virus seropositive in treatment, with tiny patches of non-cicatricial alopecia in the parieto-occipital regions of his scalp. The patient denied previous history of genital or other skin lesions. A biopsy from an alopecic patch was performed which showed an inflammatory non-scarring alopecia with a discrete lymphocytic type inflammatory infiltrate localized in the peribulbar region. There was lymphocyte exocytosis into the matrix, associated with vacuolar degeneration, and scattered apoptotic cells were observed. Plasma cells were scattered. Immunohistochemical studies showed the presence of T. pallidum limited to the peribulbar region and penetrating into the follicle matrix. To the authors' knowledge, this is the first time that spirochetes have been shown in the hair follicle in alopecia syphilitica, suggesting that the spirochetes may be pathogenetic and responsible for the alopecia.

Symmetrical alopecia, scaling and hepatitis in a rabbit

A 5-year-old rabbit with inappetence, symmetrical alopecia and skin lesions was examined. No mites or Malassezia were found in skin scrapings and tape impressions and dermatophyte culture was negative. Trial therapy with ivermectin did not reduce skin lesion severity, and euthanasia was performed because of anorexia after 1 month. Histopathology of the skin showed hyperkeratosis, lymphocytic exocytosis, cell-poor interface dermatitis (lymphocytic infiltration and apoptotic cells in basal layer of epidermis), absence of sebaceous glands and lymphocytic mural folliculitis comparable to sebaceous adenitis and thymoma-associated exfoliative dermatitis previously described in rabbits. The liver exhibited an interface hepatitis, comparable to autoimmune hepatitis in man. The occurrence of morphological similarities to exfoliative dermatitis and sebaceous adenitis in rabbits, in association with an autoimmune hepatitis, has not been described before.

A case of flagellation

Conflict of interest: none declared A 58‐year‐old man presented with a 3‐day history of a striking flagellate dermatitis on his thighs and trunk (Fig. 1a,b), which were intensely pruritic. There was no dermographism. He had taken no new medication but had been on antiretroviral therapy for human immunodeficiency virus for many years. There were no other symptoms. Full blood count, including eosinophil count, and measurement of serum creatine kinase were normal. The previous night he had eaten a Chinese meal. ... A skin biopsy was performed (Fig. 2). He was treated with antihistamines and potent topical corticosteroids. The dermatitis settled within 2 weeks, leaving no pigmentary change. ... Histological sections showed mild to moderate spongiosis with focal hyperkeratosis, mid‐parakeratosis and minimal exocytosis of lymphocytes. In the superficial and mid dermis there was a mild, perivascular, lymphohistiocytic inflammatory cell infiltrate. What is your diagnosis? Flagellate dermatitis due to shiitake mushroom ingestion.

Erythema Multiforme-like Targetoid Lesions in Secondary Syphilis

A 37-year-old woman presented with a 6 week history of pruritic targetoid lesions, which were violaceous, erythematous plaques in an annular pattern, 1–2 cm in size, on both palms (Fig. 1). She had no prior history of medication or herpes simplex infection before the skin lesions occurred. All other physical findings were normal. The clinical findings suggested EM. Skin biopsy performed on the palm was consistent with interface dermatitis, and showed hyperkeratosis, lymphocytic exocytosis, and vacuolization of the basal layer. A mild perivascular lymphohistiocytic infiltrate without plasma cells was present throughout the papillary dermis (Fig. 2). Proliferation of endothelial cells and a perivascular dermal infiltrate containing plasma cells, which are histological hallmarks of syphilis (2), were not seen. Warthin-Starry stain of the skin biopsy specimen was negative for spirochetes. To provide a direct association between Treponema pallidum and the targetoid skin lesions, polymerase chain reaction (PCR) technology was used to detect treponemal genomic DNA in the skin lesions. The 47-kDa lipoprotein gene (GenBank accession no. M88769 and M27493) (3, 4) for T. pallidum was amplified using 40 cycles of 94oC for 1 min, 58oC for 1 min, and 72oC for 1 min. The final product was separated on 2% agarose gel, stained with ethidium bromide, and visualized by BioPrint/Bio1D (Vilber Lourmat, France). A 658 bp band of the PCR product specific for T. pallidum was present only in the skin biopsy specimens from this patient, as in the positive control, but not in the negative control (Fig. 3). Serological tests for syphilis showed venereal disease research laboratory test titres of 1:32, and the fluorescent treponemal antibody absorption test IgM and T. pallidum haemagglutination assay were reactive.

Early vulvar lichen sclerosus: a histopathological challenge

HistopathologyVolume 50, Issue 3 p. 388-389 Early vulvar lichen sclerosus: a histopathological challenge D N Slater, D N Slater Department of Histopathology, Royal Hallamshire Hospital & Northern General Hospital, Sheffield, UKSearch for more papers by this authorB E Wagner, B E Wagner Department of Histopathology, Royal Hallamshire Hospital & Northern General Hospital, Sheffield, UKSearch for more papers by this author D N Slater, D N Slater Department of Histopathology, Royal Hallamshire Hospital & Northern General Hospital, Sheffield, UKSearch for more papers by this authorB E Wagner, B E Wagner Department of Histopathology, Royal Hallamshire Hospital & Northern General Hospital, Sheffield, UKSearch for more papers by this author First published: 22 December 2006 https://doi.org/10.1111/j.1365-2559.2007.02599.xCitations: 7Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume50, Issue3February 2007Pages 388-389 RelatedInformation

Immunopathologic study of erythema dyschromicum perstans (ashy dermatosis)

Erythema dyschromicum perstans (EDP) is a pigmentary disease of unknown etiology in which damage to basal cells is thought to be mediated by adhesion molecules. The aim of this study was to characterize the histopathology and immunopathology of EDP. Forty-three patients from Medellín, Colombia, with the diagnosis of EDP were evaluated. Skin biopsy specimens were obtained for histopathology and immunohistochemistry, using monoclonal antibodies directed against the following markers: CD4, CD8, CD56, CD1a, CD68, CLA, HLA-DR, ICAM-1 and LFA-1alpha. A dermal lymphocytic infiltrate was observed in all cases, with a perivascular location in 86%. Other histologic features included melanophages in all specimens, vacuolization of the basement membrane zone (BMZ) 58% and exocytosis of lymphocytes (53.5%). The mean number of total leukocytes was 1510 cells mm-2 of tissue. There was a predominance of CD8+ T lymphocytes in the dermis and HLA-DR+, ICAM-1+ keratinocytes in the epidermis. Exocytosis of cutaneous lymphocyte antigen (CLA)+cells was observed in areas of BMZ damage, suggesting that response to antigenic stimulation may play a role in the development of EDP.

Conjunctival T-cell Lymphoma: A Clinicopathologic Case Report

To report a patient with conjunctival T-cell lymphoma, an extremely rare entity.Single case report.Based on clinical examination, an excisional biopsy and immunostaining were performed on the conjunctival lesion. For management, we excised and performed triple freeze-thaw cryotherapy to the involved area, and we consulted the oncology service.T-cell and B-cell markers, and clinical examination of the lesion.Both examination and laboratory assessment revealed no evidence of systemic involvement. Conjunctival biopsy showed expansion of the substantia propria with an infiltrate of chronic inflammatory cells (including lymphocytes, plasma cells, and eosinophils), and prominent lymphocyte exocytosis with reactive epithelial changes. The CD-45 RO (T-cell marker) was strongly positive, whereas the CD-20 (B-cell marker) was negative. The T-cell receptor gene rearrangement was positive with beta clonality, confirming the diagnosis of T-cell lymphoma.T-cell lymphoma is a rare but possible diagnosis of gelatinous conjunctival lesions. The oncology consultants were reluctant to treat the patient with systemic chemotherapy or radiation because extraconjunctival extension could never be documented. The answer to the question of what is the most appropriate treatment for conjunctival T-cell lymphoma remains unknown.

Cytotoxic T lymphocyte exocytosis: bring on the SNAREs!

Despite our general understanding of membrane traffic, the molecular machinery at the immunological synapse (IS) that regulates exocytosis of lytic granules from cytotoxic T lymphocytes (CTLs) remains elusive. The identification of disease-causing mutations in the small GTPase Rab27a, priming factor Munc13-4 and fusion protein syntaxin11 has defined an important role for these proteins in CTL exocytosis. In addition, the demonstration of a direct interaction in vitro between Rab27a and Munc13-4 suggests the possibility that the Rab27a-Munc13-4 cascade might regulate CTL exocytosis by engaging SNAREs such as syntaxin11. We propose that these SNAREs are likely to mediate the fusion of lytic granules with the plasma membrane of the IS.