A case of systemic precursor T-cell lymphoblastic lymphoma presenting with single tooth mobility

Lymphoblastic lymphoma, seen primarily in children or young adults, is a type of non-Hodgkin lymphoma that originates from B or T lymphocyte precursors and rarely occurs in the oral cavity. A case of systemic precursor T-cell lymphoblastic lymphoma mimicking periodontitis of a lower second molar in a 20-year-old adult is currently presented. The case was initially misdiagnosed as periodontal disease and treated with tooth extraction by a dentist. Re-evaluation of the patient due to worsening of symptoms lead to cone beam computed tomography scanning that thoroughly revealed an extended osteolytic lesion of the right mandible. Afterward, a biopsy was performed, thus reaching the diagnosis of precursor T-cell lymphoblastic lymphoma. This report discusses differences in epidemiology of T-cell and B-cell lymphoblastic lymphomas, as well as their various intraoral manifestations that are mimicking a large family of oral pathology. It also focuses on conventional imaging findings that imply malignancy, which are often neglected during routine radiology interpretation.

Oral neural tumors: Clinicopathologic analysis of 157 cases and review of the literature

Background

Oral neural tumors (ONTs) are rare lesions and represent reactive or neoplastic proliferations of nerve sheath cells. The purpose of the present study is to report the clinical, demographic and histopathologic features of 157 ONTs diagnosed in a single Oral Pathology Department and review the pertinent literature.

Material and Methods

157 cases of ONTs diagnosed during a 44-year period were retrospectively collected and the diagnosis was reconfirmed by studying representative haematoxylin and eosin stained tissue sections. The patients’ gender and age, as well as the main clinical features of the lesions, were retrieved from the biopsy submission forms.

Results

The 157 ONTs represented approximately 0.4% of 35,590 biopsies accessioned during the study period. They affected 71 male and 86 female patients with a mean age of 38.4±18.8 years. They mainly appeared as asymptomatic nodules of normal or white colour on the tongue, lip mucosa and hard palate. The most common ONT was granular cell tumour (38.9%) followed by neurofibroma (19.7%), schwannoma (15.9%), traumatic neuroma (15.9%), palisaded encapsulated neuroma (8.3%) and nerve sheath myxoma (1.3%).

Conclusions

This study confirmed the rarity of ONTs. Their clinical characteristics mimic other oral lesions; thus, microscopic examination is the only mean to arrive at a definitive diagnosis.

Key words:Oral neural tumors; oral neural neoplasms; neurofibroma; oral neurofibroma; schwannoma; oral schwannoma; neurilemmoma; oral neurilemmoma; granular cell tumor; oral granular cell tumor; traumatic neuroma; oral traumatic neuroma; palisaded encapsulated neuroma; oral palisaded encapsulated neuroma.

Atypical methotrexate ulcerative stomatitis with features of lymphoproliferative like disorder: Report of a rare ciprofloxacin-induced case and review of the literature

Methotrexate (MTX) is an established immunomodulating agent used in low doses (LDMTX) to treat several autoimmune diseases. Ulcerative stomatitis (US) may be observed as a long-term LDMTX adverse effect showing a wide histopathologic spectrum. A 73-year old female presented with painful oral ulcers of 5 days duration. The patient had been under treatment for rheumatoid arthritis with LDMTX, while one week before presentation she was prescribed ciprofloxacin for a urinary infection. Histopathologic examination of a lingual ulcer revealed a polymorphous lymphohistiocytic proliferation with scattered binucleated atypical lymphocytes. Immunohistochemically, most cells were of T-cell lineage while the EBER test was negative and a diagnosis of MTX-induced reactive ulceration was rendered. MTX cessation resulted in complete resolution of the ulcers with no recurrences reported so far. The clinical and histopathologic features of MTX-induced oral ulcers are not always diagnostic and a detailed history and an extensive clinicopathologic investigation may be needed to exclude a lymphoproliferative disorder.

Key words:Atypical oral ulcers, ciprofloxacin, lymphoproliferative disorders, methotrexate.

Reactive osteocartilaginous metaplasia in denture wearers: a rare trauma-related lesion

OBJECTIVE

To present a case of reactive osteocartilaginous metaplasia (ROCM) in the anterior edentulous mandibular ridge.

BACKGROUND

The ROCM secondary to chronic mechanical denture trauma is rare and appears as a focal sometimes painful mass on or near the crest of the edentulous alveolar ridge in long-term denture wearers. The literature review disclosed 24 cases involving more commonly the posterior portion of the mandible.

MATERIALS AND METHODS

An 80-year-old female was referred for the evaluation of a painful, submucosal nodule extending into the vestibular mucosa of the anterior edentulous mandibular region. Microscopically, cartilaginous regions exhibiting sparse hyperchromatic or binucleated chondrocytes transitioned into areas of ossification.

RESULTS

The diagnosis was ROCM. The presence of osteocartilaginous tissue displaying bizarre histopathological features can create a diagnostic dilemma.

CONCLUSION

Complete conservative surgical excision of this lesion has a very good prognosis. Surgical augmentation of the sharp edentulous mandibular ridges might be needed to avoid continuous irritation and possible recurrence.

Atypical Presentation of an Upper Lip Pleomorphic Adenoma: Case Report

The pleomorphic adenoma (PA) or mixed tumor is the most common neoplasm of the salivary glands, usually presenting with a non-specific clinical manifestation and a diverse histopathological pattern. The region of the lips is the second most common site for minor gland neoplasms. The aim of this paper is to report the case of a 39 year old caucasian woman presenting with a swelling on the right side of the upper lip combined with a history of trauma in the region of the upper right central incisor, eight years ago. The swelling was attributed to the periapical lesion of the upper right central incisor that was observed on the orthopantomography. Intraoperatively the surgeon came upon a nodule of firm consistency in the mucolabial fold. The histopathologic diagnosis of this lesion was benign mixed tumor of salivary gland. This report discusses the deviation in frequency of mixed salivary gland tumor between upper and lower lip, the clinical differential diagnosis, the histopathological pattern and the appropriate treatment.

Retrieval analysis of immediately loaded orthodontic mini-implants: material and tissue characterization

OBJECTIVE

To investigate the morphological and compositional alterations of retrieved orthodontic mini-implants and the type of adjacent bone, in relation to loading period and anatomical region.

MATERIALS AND METHODS

Seventy orthodontic mini-implants (Aarhus: n = 35 and AbsoAnchor: n = 35) were placed in the maxilla and mandible of 33 orthodontic patients for anchorage purposes. All mini-implants were immediately loaded for a period specified by treatment plan. Fifty-nine mini-implants were retrieved (Aarhus: n = 29 and AbsoAnchor: n = 30) and examined by stereomicroscopy, reflection Fourier transform infrared microspectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Tissue samples adjacent to the implants were histologically examined to identify the bone type.

RESULTS

Changes in surface finish, formation of biological integuments, and compositional alterations mainly due to adsorption of proteinaceous material (rich in C, O, N, OH, NH, CH2/CH3, amide I, II, and III, and CH-OH) were identified in all mini-implants. In some cases, mineralized fragments were identified (rich in Ca, P, and Ca-P). In 25 out of the 59 histological sections examined, woven and lamellar bone types were detected. In 12 sections, only woven bone was detected, whereas in the residual 22, only lamellar bone was identified. A significant correlation was found between histological result and loading time but not between histology and region.

CONCLUSION

Morphological and elemental alterations were found for both types of mini-implant surfaces. An increase of the loading period increased the possibility of lamellar bone development around mini-implants.

Comparison of lateral thermal injury and healing of porcine skin incisions performed by CO2-laser, monopolar electrosurgery and radiosurgery: a preliminary study based on histological and immunohistochemical results

BACKGROUND

Despite the wide application of lasers and electrosurgery in dermatology, the pertinent literature provides conflicting data regarding the lateral thermal injury (LTI) associated with these instruments and its effects on wound healing. This study aims to quantitate the LTI produced by CO(2)-laser, monopolar electrosurgery (MES), and radiosurgery (MRS) and determine its effects on the healing process (re-epithelialization and inflammatory response) of incisional wounds.

METHODS

Five adult swine of similar weight (22.8-25 kg) were submitted to standardized full-thickness incisions on the lateral abdominal skin by the above instruments (at settings similar to those used in clinical practice) and scalpel (control group). Full-thickness specimens from the surgical site were harvested immediately afterwards and 48 hours later (days 1 and 3). The animals were euthanized by intravenous administration of propofol and pentobarbital. All specimens were formalin fixed, paraffin embedded, cut, and stained with hematoxylin-eosin to quantitate the extent of LTI and inflammatory infiltration. Sections of day 3 were stained with the MIB-1 monoclonal antibody to detect Ki-67 as a marker of epithelial cell proliferation adjacently to the incisions.

RESULTS

LTI was most extensive in the CO(2)-laser-group but did not differ significantly between MES- and MRS-groups. Immunohistochemistry ascertained significantly greater epithelial cell proliferation in the CO(2)-laser-group. Inflammatory infiltration was significantly greater in the CO(2)-laser-group, when compared with the controls but did not differ significantly between the MES/MRS and control groups.

CONCLUSION

CO(2) laser incisions exhibit more extensive LTI, epithelial cell proliferation, and inflammatory response. Confirmation of these findings requires a greater sample.

Novel mutations of the HRAS gene and absence of hotspot mutations of the BRAF genes in oral squamous cell carcinoma in a Greek population

Oral squamous cell carcinoma (OSCC) is the sixth most common cancer in the world. The phosphatidylinositol 3 kinase (PI3K) signalling pathway has been reported to play an important role in OSCC. Since we have previously detected absence of hotspot PIK3CA gene mutations in the Greek population, we hypothesized that BRAF or HRAS may be activated as upstream effectors of the pathway. Furthermore, the status of the HRAS and BRAF mutations in OSCC has never been assessed before in the Greek population. Eighty-six primary paraffin-embedded tumors were screened for BRAF and HRAS hotspot mutations. In HRAS, two hotspot mutations in codon 12 (2.3%) and eight new genetic alterations were detected (8.6% overall). One new missense mutation, Alanine53Valine (Ala53Val), one silent mutation, two mutations in the 5'UTR region and four mutations in intron 1 were detected. No hotspot mutations in Braf were found. A new silent mutation/polymorphism T1803C was detected at a percentage of 30%. This study is the first to report HRAS mutations in the Greek population. The results suggest that RAS is an important member of the PI3K signalling pathway and may play a role in the tumorigenesis of OSCC.

Increased TNF-α, IL-6 and decreased IL-1β immunohistochemical expression by the stromal spindle-shaped cells in the central giant cell granuloma of the jaws

Objectives: the exp ress ion of the osteoclastogenic cytokines TNF-α, IL-6 and IL-1β were immunohistochemically evaluated in periph eral (PGCG) and central (CGCG) giant cell granulomas of the jaws in order to determine diff erences between these two lesions and between the two distinct tumor cell populations (multinucleated giant cells, MGCs and stromal sp indle-sh aped cells). Study Design: Paraffin-embedd ed tiss ue sections from 40 PGCG and 40 CGCG were immunohistochemically stained using antibodies against TNF-α, IL-6 and IL-1β. The percentage of positively stained cells and the staining intensity were ass ess ed to provide a combined immunoreactivity score value. Results: TNF-α, IL-6 and IL-1β were exp ress ed in all lesions. The CGCG compared to the PGCG sh owed significantly increased exp ress ion of TNF-α and IL-6 and decreased exp ress ion of IL-1β by the sp indle-sh aped cells and increased exp ress ion of IL-1β by the MGCs. The MGCs demonstrated in comparison to the stromal sp indlesh aped cells significantly increased exp ress ion of all three cytokines in both PGCG and CGCG. Conclusions: The proinflammatory cytokines TNF-α, IL-6 and IL-1β seem to be involved in the growth process of PGCG and CGCG of the jaws. A poss ible alteration in the sy nthesis or/and activity of these cytokines by the stromal sp indle cells in the CGCGs may enhance osteolys is through the stimulation of osteoclast progenitor cells, given the fact that the intraoss eous lesions cause bone resorption.

Key words: Giant cell granuloma, giant cell tumor, multinucleated giant cells, jaw, TNF-alpha, IL-6, IL-1beta, immunohistochemistry.

Oral acanthosis nigricans in chronic hepatitis B with a 21-year follow up

Acanthosis nigricans is a rare mucocutaneous disorder of unknown etiology that manifests as hyperpigmented velvety plaques, most often on intertriginous areas such as the neck and axillae as well as on mucosal sites such as the oral cavity. The disorder presents either as a paraneoplastic manifestation of an underlying malignancy, especially gastrointestinal adenocarcinomas or in association with obesity, administration of drugs or endocrinopathies, most commonly insulin-resistant diabetes mellitus. In the present article, a case of acanthosis nigricans with oral and cutaneous manifestations in a male patient with chronic hepatitis B infection is described. To the best of our knowledge, this is the first case of benign oral acanthosis nigricans associated with chronic hepatitis B.

Infected lingual osseous choristoma. Report of a case and review of the literature

Osseous choristoma is a rare, benign lesion of the oral cavity occurring usually in the tongue. It appears as a tumorous mass of normal bony structure with mature cells in an ectopic position. The case of a 72 years Caucasian male is presented and analyzed along with 52 similar cases reported in the English literature between 1967 and 2007. Lingual choristoma shows a female predilection, whereas the commonest anatomic location is the posterior third of the tongue, occurring at or close to the foramen caecum and the circumvallate papillae. Histologically the lesions show signs of a well-circumscribed mass of vital bone located under the surface oral epithelium. Some lesions represent developmental malformations, whereas others may be reactive lesions after trauma or chronic irritation. Treatment of lingual osseous choristoma consists of simple excision.

Factor XIIIa+ dendritic cells and S-100 protein+ Langerhans' cells in adult periodontitis

OBJECTIVE

The purpose of this study was to evaluate the presence of factor XIIIa+ dendritic cells and S-100 protein+ Langerhans' cells in the gingival epithelium and connective tissue of periodontal pockets, before and after non-surgical periodontal therapy.

BACKGROUND

The microbial flora in periodontal pockets provokes complex immune reactions. Dendritic cells play a critical role in primary and secondary immune responses and are considered as antigen-presenting cells. Factor XIIIa positive dendritic cells and S-100 protein positive Langerhans' cells identified by immunoreactivity against factor XIIIa antigen and S-100 protein, respectively, are two distinct subpopulations of dendritic cells.

METHODS

Fifty-four gingival tissue samples were obtained from periodontal pockets of initial depth 4-5 mm and > or = 6 mm. Each group was subdivided in to three subgroups. The first subgroup consisted of samples taken on baseline day and used as control. The second and third subgroups included those obtained 1 month after plaque and calculus removal, and 1 month after scaling and root planing, respectively, additionally to oral hygiene instructions. The tissues were removed from the palatal gingiva under local anaesthesia during routine periodontal surgery. Immunohistochemical staining with antibodies against factor XIIIa and S-100 protein was performed to identify dendritic cells positive and Langerhans' cells positive, respectively.

RESULTS

Factor XIIIa+ dendritic cell numbers decreased compared to controls after plaque and calculus removal, oral hygiene instructions and scaling and root planing in periodontal pockets of 4-5 mm, but not in those of > or = 6 mm depth. S-100+ Langerhans' cell numbers decreased after periodontal treatment in the periodontal pockets > or = 6 mm.

CONCLUSION

These results may reflect a tendency for reduction of these two distinctive subpopulations of dendritic cells after non-surgical periodontal therapy.

Elevated serum levels of the apoptosis related molecules TNF-alpha, Fas/Apo-1 and Bcl-2 in oral lichen planus

BACKGROUND

The serum circulatory levels of apoptosis related molecules measured in patients with oral lichen planus (OLP) and healthy individuals in order to investigate possible alterations associated with the clinical forms of OLP.

METHODS

Serum levels of tumor necrosis factor (TNF)-alpha, soluble Fas (sFas) and Bcl-2 studied by enzyme-linked immunosorbent assay in whole blood samples in 13 OLP reticular, 13 OLP atrophic-erosive form patients and 26 healthy subjects.

RESULTS

Significantly elevated levels of TNF-alpha and sFas detected in OLP patients as compared with controls. Serum concentrations of Bcl-2 although increased in 17/26 patients, they were not statistically significant. Reticular OLP exhibited slightly elevated TNF-alpha and significantly elevated Bcl-2 serum levels, compared with erosive OLP.

CONCLUSIONS

These data suggest that a putative dysfunction in the Fas/FasL mediated apoptosis might be involved in the OLP pathogenesis. A downregulation of Bcl-2 serum levels in the atrophic-erosive OLP may be associated with promotion of the disease activity.

Immunohistochemical evaluation of cell proliferation antigen Ki-67 and apoptosis-related proteins Bcl-2 and caspase-3 in oral granular cell tumor

PURPOSE

We sought to evaluate the cell proliferation activity and immunohistochemical expression of proteins that promote or inhibit apoptosis in oral granular cell tumor (GCT).

STUDY DESIGN

Immunohistochemistry for Ki-67, a cell proliferation marker; Bcl-2, an anti-apoptotic protein; and caspase-3, a protein implicated in the execution of apoptosis, was performed on tissues from 12 patients with GCT of the tongue.

RESULTS

Nuclear immunostaining for Ki-67 was observed only in isolated GCs (less than 2%). All patients exhibited cytoplasmic immunoreactivity for Bcl-2 in the majority of tumor cells. Cytoplasmic staining for caspase-3 was also present in more than 50% of GCs in all tumors.

CONCLUSIONS

GCT cells display low proliferation activity, a finding possibly related to their benign behavior. Caspase-3 expression suggests activation of the apoptotic cascade in the GCs, but persistence of the cells in the tissues could be attributed to the expression of Bcl-2 protein, a molecule that functions as a survival factor.

TNF-alpha expression and apoptosis-regulating proteins in oral lichen planus: a comparative immunohistochemical evaluation

Apoptosis appears to be the mode of cell death by which damaged cells are removed from the lesional tissue in oral lichen planus (OLP). In the present study, OLP biopsies were immunohistochemically evaluated for TNF-alpha and apoptosis-regulating proteins in an attempt to compare their phenotypic expression. Deparaffinized tissue sections from 22 OLP and 10 control oral biopsy specimens were immunohistochemically stained with anti-Bcl-2, anti-Bcl-x, anti-Bax and anti-TNF-alpha antibodies. Keratinocytes did not show any immunoreactivity for Bcl-2, while a uniform intense staining for this protein was evident in the lymphocytic infiltrate of OLP specimens. Immunoreactivity for TNF-alpha was seen in 17/22 OLP cases. All control tissues were TNF-alpha negative, thus indicating a possible involvement of this cytokine in the pathogenesis of OLP The differences in the staining intensities of Bcl-x and Bax between OLP and normal epithelium were slight; therefore an obvious association of the phenotypic TNF-alpha expression with these apoptosis-regulating proteins was not apparent.

p53, p21, Rb, and MDM2 proteins in tongue carcinoma from patients < 35 versus > 75 years

Relatively rare squamous cell carcinomas of the tongue in young patients may be associated with different etiologic factors and pathogenetic mechanisms than carcinomas from the same site in older patients. Alterations in cell cycle proteins likely contribute to the biologic behavior of these neoplasms. The purpose of this investigation was to evaluate cell cycle proteins (p53, p21, Rb, MDM2) in lateral tongue cancers from patients at the two ends of the age spectrum. All available archived lateral tongue carcinomas from patients < 35 years (n = 36, 23 males and 13 females) were sectioned, immunohistochemically stained, and evaluated. Protein expression was scored as percent positive nuclei. An equal number of sequentially accessioned lateral tongue specimens from patients > 75 years (23 males and 13 females) were stained and compared. Positive p53 staining was seen in 18/36 of the < 35-year group versus 24/36 of the > 75-year group (p = 0.149). Increased p21 staining (both percent of positive cells and intensity) was evident in 25/32 of the < 35-year group versus 24/32 of the > 75-year group (p = 1.0). Increased p21 expression was seen in both p53-positive and -negative cases in both age groups. Rb protein was increased in 16/29 of the < 35-year group versus 17/26 of the > 75-year group (p = 0.58). Fourteen cases (4/35 vs 10/36, p = 0.135) showed positive MDM2 staining; MDM2-positive cases were also p53 positive in 4/4 younger and 8/10 older patients. We conclude that p53, p21, Rb, and MDM2 are over-expressed in lateral tongue cancers, and that immunohistochemical profiles are heterogeneous. A p53-independent pathway of p21 induction is supported by the results; p53 suppression may be associated with MDM2 protein expression in a subset of cancers. Significant differences in the expression of p53, p21, Rb, and MDM2 proteins are not evident in lateral tongue carcinomas from patients < 35 years as compared to patients > 75 years.

Benign neural tumors of the oral cavity: a comparative immunohistochemical study

To determine if immunohistochemistry can be used as adjunct to the diagnosis and classification of oral benign neural tumors, we stained 77 neurally differentiated tumors with a panel of neural-associated antibodies (S-100 protein, CD57, epithelial membrane antigen, factor XIIIa, CD34, CD68, collagen IV). Using standard histologic criteria, we identified 13 schwannomas, 16 neurofibromas, 23 traumatic neuromas, 16 palisaded and encapsulated neuromas, and 9 granular cell tumors from archived oral pathology specimens. Silver stains showed that neurofibromas, traumatic neuromas, and palisaded and encapsulated neuromas consistently contained axon filaments. Although all neural tumors contained S-100-positive cells, schwannomas and palisaded and encapsulated neuromas contained the most. All tumors expressed CD57; traumatic neuromas were stained intensely and the others stained weakly. The consistent epithelial membrane antigen capsular staining of schwannomas and the absence of factor XIIIa-positive dendritic/spindle cells helped distinguish these tumors from others. Many CD34-positive cells were found in schwannomas, and few were found in palisaded and encapsulated neuromas. Variable numbers CD68-positive cells were seen in all neural tumor types; some of these cells appeared to be macrophages and mast cells, but many were thought to be Schwann cells expressing this antigen. Collagen IV staining, apparently representing basement membrane, was generally a feature of all benign neural tumors. The immunophenotype of the granular cells of the GCTs was S-100+, CD57+, and collagen IV+ supporting the putative neural origin of these tumors. We conclude that neural origin/differentiation of a connective tissue tumor can be confirmed with stains for S-100 protein, epithelial membrane antigen, CD57, and collagen IV. Staining patterns and intensities associated with the panel of antibodies tested can be useful in tumor classification.

Apoptosis in oral erythema multiforme

OBJECTIVE

Cell death was evaluated in oral erythema multiforme to test the hypothesis that apoptosis may be a mechanism by which keratinocytes die in this condition.

STUDY DESIGN

Ten erythema multiforme and five control oral mucosa biopsy specimens were evaluated in immunohistochemically stained sections for apoptosis-regulating proteins Bcl-2, Bcl-x, Bax, p53, Fas, and Fas-ligand. Apoptotic keratinocytes, determined by a detection method for DNA fragmentation (TUNEL) and by conventional morphologic criteria were counted per high power field.

RESULTS

Keratinocyte staining for Bcl-2 protein was comparable in erythema multiforme and controls. Bcl-x expression was reduced in five erythema multiforme cases. Staining for Bax protein differed in six erythema multiforme cases and showed variable intensity in layers under the parakeratin. Only slight differences in staining patterns of Fas and Fas-ligand proteins were noted between erythema multiforme and controls. The number of apoptotic keratinocytes evaluated by morphologic examination was significantly higher in erythema multiforme (mean per high power field, 0.90 +/- 0.2; controls, 0.06 +/- 0.04; p < 0.05, Mann-Whitney test) and was limited in significance by the TUNEL method (erythema multiforme, 0.43 +/- 0.1; controls, 0.02 +/- 0.02). Overexpression of p53 protein was seen in basal keratinocytes in five erythema multiforme specimens (mean, 17.5 +/- 4.03 per high power field; controls 1.2 +/- 0.3).

CONCLUSIONS

There is evidence that cell death in erythema multiforme is at least in part due to apoptosis. The apoptotic mechanism may be related to an altered expression of apoptosis-regulating proteins. Although measurable alterations in the phenotypic expression of Fas and Fas-ligand proteins were not apparent, activation of Fas/Fas-ligand system could still be involved in the induction of apoptosis in erythema multiforme.

Apoptosis-associated proteins in oral hairy leukoplakia

OBJECTIVE

To test the hypothesis that the anti-apoptotic ability of Epstein-Barr virus (EBV) may result in altered expression of apoptosis-associated proteins in oral hairy leukoplakia (HL), we evaluated HL tissue and normal epithelium for these proteins by immunohistochemistry.

MATERIALS AND METHODS

Twenty formalin-fixed, paraffin-embedded specimens of HL lesions and six specimens of normal control mucosa were selected from archived tissue specimens. Bcl-2, Bcl-x, Bax and p53 apoptosis-associated proteins were evaluated in immunohistochemically stained tissue sections according to staining intensity and pattern. The percentage of p53-positive basal cells was estimated in sequential fields.

RESULTS

Generally, there were only slight differences in the expression of Bcl-2 and Bcl-x proteins in the epithelium of HL and control tissue. The staining for Bcl-2 was weaker in keratinocytes than in putative melanocytes and Langerhans cells. Equivocal diffuse cytoplasmic staining of prickle cells was also noted. Keratinocytes throughout the epithelium stained positively for Bcl-x protein, although upper layers were more weakly stained. The 'balloon' keratinocytes in HL were infrequently positive for Bcl-x. Bax staining in HL differed from that in control tissue in being more heterogeneous. The staining reaction in HL was weak to negative in upper epithelial levels where 'balloon' keratinocytes were located. Weak to moderate nuclear p53 protein staining was detected in a mean of 25.3% of basal keratinocytes in all but one of the HL specimens; weak staining was seen in only two control specimens.

CONCLUSIONS

We found only slight immunohistochemical evidence that expression of the apoptosis-associated proteins is altered in HL. p53 appears to over-expressed in HL; we speculate that this may be related to up-regulation or stabilization of wild-type p53 protein related to EBV infection.