Mast Cells In Lesions Research Articles

Mast Cell Profile in Benign and Malignant Prostatic Lesions

Introduction: Mast cells have an important role in innate and adaptive immunity. There role in tumour pathology is under investigation due to studies linking them to angiogenesis, tissue remodeling and stromal immunomodulation. Reports suggest that they can exert both pro or anti tumour effects. The role of mast cells may be influenced by its location in the lesion. In the present study, the number and distribution of mast cells in both benign and malignant prostatic lesions were recorded. Methodology: Fifty seven patients of benign prostatic hyperplasia (BPH) and 43 patients of adenocarcinoma (Ca) were the subjects of the study. Inflammatory conditions of prostate like prostatitis and other malignancies of prostate like sarcoma, transitional cell carcinoma etc were excluded from the study. This was a descriptive study with purposive sampling. Histological diagnosis was made by examining sections stained with Haematoxylin and Eosin. Additional sections from the same block were stained for mast cells using Giemsa stains as per standard protocol. Mast cell count was done in minimum 6 random high power microscopy field in four different regions viz., intraglandular, periglandular, stromal and perivascular regions for BPH and intratumoral, peritumoral, stromal and perivascular regions for Ca. Results were analysed statistically. Results: In BPH cases showed a significantly higher number of mast cells in stromal as well as periglandular areas followed by perivascular area. Only few mast cells were observed in intraglandular area. Similar was the observations in adenocarcinoma cases where the maximum number of mast cells were concentrated in the stromal and perilesional area. The number of mast cells in stroma of BPHwas higher as compared to that of adenocarcinoma. In rest of the areas, the numbers were comparable. Conclusion: This study showed no remarkable difference in the number and distribution of mast cells in benign and malignant prostatic lesions. There is paucity of such studies in the literature and the possible utility of mast cell count to differentiate malignant from benign and atypical conditions needs further evaluation.

Comparative Study of Histopathological Patterns and Mast Cells in Cutaneous Lichen Planus and Lichenoid Lesions

Background Besides lichen planus various other skin lesions like erythema multiforme, pityriasis lichenoides, etc., show lichenoid reaction pattern. This study was aimed to compare the histological features and number of mast cells in cutaneous lichen planus and lichenoid lesions. Studies have shown increase in mast cell numbers in mucosal lichen planus and lichenoid lesions. Methods Tissue sections of lichen planus and lichenoid lesions, (forty samples for each group) were studied. All the epidermal, dermal changes and mast cell numbers were noted. Results Epidermal and dermal changes like acanthosis, hypergranulosis, hyperkeratosis, location of inflammatory cells, severity of inflammation and basement membrane thickness were statistically significant between the two groups. Cases with severe inflammation showed thin and disrupted basement membrane, severe capillary proliferation and severe basal cell vacuolation. The number of mast cells was not significant on comparison between the two groups. Conclusion The epidermal and dermal changes were consistent with usual histopathological findings in these lesions. The mast cell number was not significant on comparison, which may be due to the common and overlapping mechanisms in the pathogenesis of inflammation in both the groups.

Human mast cell neutral proteases generate modified LDL particles with increased proteoglycan binding

Background and aimsSubendothelial interaction of LDL with extracellular matrix drives atherogenesis. This interaction can be strengthened by proteolytic modification of LDL. Mast cells (MCs) are present in atherosclerotic lesions, and upon activation, they degranulate and release a variety of neutral proteases. Here we studied the ability of MC proteases to cleave apoB-100 of LDL and affect the binding of LDL to proteoglycans. MethodsMature human MCs were differentiated from human peripheral blood-derived CD34+ progenitors in vitro and activated with calcium ionophore to generate MC-conditioned medium. LDL was incubated in the MC-conditioned medium or with individual MC proteases, and the binding of native and modified LDL to isolated human aortic proteoglycans or to human atherosclerotic plaques ex vivo was determined. MC proteases in atherosclerotic human coronary artery lesions were detected by immunofluorescence and qPCR. ResultsActivated human MCs released the neutral proteases tryptase, chymase, carboxypeptidase A3, cathepsin G, and granzyme B. Of these, cathepsin G degraded most efficiently apoB-100, induced LDL fusion, and enhanced binding of LDL to isolated human aortic proteoglycans and human atherosclerotic lesions ex vivo. Double immunofluoresence staining of human atherosclerotic coronary arteries for tryptase and cathepsin G indicated that lesional MCs contain cathepsin G. In the lesions, expression of cathepsin G correlated with the expression of tryptase and chymase, but not with that of neutrophil proteinase 3. ConclusionsThe present study suggests that cathepsin G in human atherosclerotic lesions is largely derived from MCs and that activated MCs may contribute to atherogenesis by enhancing LDL retention.

Role of mast cells in Staphylococcus aureus enterotoxin Binduced atopic dermatitis-like skin inflammation in mice

Objective To investigate the role of mast cells in Staphylococcus aureus enterotoxin B (SEB) -induced atopic dermatitis (AD) -like skin inflammation in BALB/c mice. Methods A total of 24 BALB/c mice were randomly and equally divided into 4 groups to be topically treated with ovalbumin (OVA group) , SEB (SEB group) , OVA+ SEB (OVA+ SEB group) and sodium chloride physiological solution (control group) respectively, so as to establish mouse models of epicutaneously induced AD-like skin inflammation. The AD-like skin lesions were evaluated by clinical observation and eczema area and severity index (EASI) . Biopsy specimens were obtained from lesional skin of mice and then subjected to toluidine blue staining and immunohistochemical staining to count the mast cells, observe the morphology and distribution of mast cells, and calculate the percentage of degranulated mast cells. Results After 7-week treatment, the OVA group, SEB group and OVA+ SEB group all showed severer local skin inflammation, higher EASI scores and denser infiltration of inflammatory cells compared with the control group. Moreover, the OVA+ SEB group showed significantly severer local skin inflammation, skin lesions and degree of infiltration of inflammatory cells compared with the OVA group and SEB group (all P < 0.05) . The number of mast cells in the dermis of AD-like skin lesions per high-power field (× 400) was significantly higher in the OVA group (median[quartile range]: 10.625[3.675]) , SEB group (11.000[4.163]) and OVA+ SEB group (13.875[8.813]) than that in the control group (5.925[2.088], all P < 0.05) . The SEB group (71.083% ± 14.519%) and OVA+ SEB group (58.767% ± 16.978%) both showed significantly higher percentage of degranulated mast cells compared with the OVA group (24.050% ± 11.161%, both P < 0.05) and control group (23.617% ± 8.132%, both P < 0.05) . Bivariate correlation analysis showed that the number of mast cells in the skin lesions was positively linearly correlated with the EASI scores (P < 0.05) . Conclusions Epicutaneous application of SEB can induce AD-like skin lesions in mice, and can exacerbate the severity of OVA-induced AD-like skin lesions. Mast cell proliferation, activation/degranulation and tryptase release may participate in the inflammation. Key words: Dermatitis, atopic; Mast cells; Staphylococcus aureus; Enterotoxins; Tryptases; Ovalbumin

Evaluation of mast cells in oral premalignant and malignant lesions: A histochemical study.

Introduction:Oral leukoplakia, oral submucous fibrosis, and oral lichen planus are the precancerous or potentially malignant lesions and conditions whereas oral squamous cell carcinoma (OSCC) is a cancerous or malignant lesion of the oral cavity. They have characteristic clinical and histopathological features. These diseases not only originate from epithelium but also associated with chronic inflammation juxta-epithellialy. Mast cells present in the connective tissue stroma and release pro-inflammatory and mitogenic cytokines. These functions of mast cells contribute and enhance the pathogenesis translation of diseases.Aim:The study was done to histologically evaluate the number of mast cells in oral epithelial dysplasia and OSCC and compare it with normal oral mucosa (NOM).Materials and Methods:Forty-five cases each of oral dysplasia, OSCC and ten cases of NOM were studied for mast cell number using toluidine blue.Results:There was a highly significant increase of mast cells in oral epithelial dysplasia on comparison with OSCC whereas there was only a significant increase in mast cells in OSCC on comparison with NOM.Conclusion:The literature has proven that mast cells can be an indicator of increased angiogenesis and hence can help in the prediction of carcinogenesis, its progression, and also the prognosis of the malignant lesions.

Density of mast cells and intensity of pruritus in psoriasis vulgaris: a cross sectional study

Background:Psoriasis is a chronic and prevalent disease, and the associated pruritus is a common, difficult-to-control symptom. The mediators involved in psoriatic pruritus have not been fully established. Objective:To evaluate associations between the number of mast cells in psoriatic lesions and the intensity of pruritus. Methods:29 patients with plaque psoriasis were recruited. In all participants, Psoriasis Area and Severity Index and Body Surface Area were assessed. A questionnaire was administered to obtain clinical information and the Dermatology Life Quality Index. Pruritus was assessed using a visual analog scale and skin biopsies were performed for staining with Giemsa and Immunohistochemistry with C-Kit. Results:Pruritus was observed in 91.3% of our patients. Median VAS was 6 (p25-75: 2-8). The immunohistochemical method revealed a mean of 11.32 mast cells/field and Giemsa staining revealed a mean of 6.72 mast cells/field. There was no correlation between the intensity of pruritus and mast cell count, neither in Immunohistochemistry (p = 0.15; rho = -0.27) nor in Giemsa (p = 0.16; rho = -0.27). Pruritus did not impact on the Dermatology Life Quality Index (p = 0.51; rho = -0.13). Study limitations:The small sample size may be considered the main limitation of our study. Conclusions:Although mast cells are mediators of pruritus in many cutaneous diseases, our findings support that psoriatic pruritus is a complex disorder with multifactorial, complex pathophysiology, involving pruritogenic mediators others than mast cells.

Mast cell inhibition as a therapeutic approach in fibrodysplasia ossificans progressiva (FOP).

Episodic flare-ups of fibrodysplasia ossificans progressiva (FOP) are characterized clinically by severe, often posttraumatic, connective tissue swelling and intramuscular edema, followed histologically by an intense and highly angiogenic fibroproliferative reaction. This early inflammatory and angiogenic fibroproliferative response is accompanied by the presence of abundant mast cells far in excess of other reported myopathies. Using an injury-induced, constitutively-active transgenic mouse model of FOP we show that mast cell inhibition by cromolyn, but not aprepitant, results in a dramatic reduction of heterotopic ossification. Cromolyn, but not aprepitant, significantly decreases the total number of mast cells in FOP lesions. Furthermore, cromolyn specifically diminishes the number of degranulating and resting degranulated mast cells in pre-osseous lesions. This work demonstrates that consideration of FOP as a type of localized mastocytosis may offer new therapeutic interventions for treatment of this devastating condition.

Effect of orally administered exopolysaccharides produced by Lactococcus lactis subsp. cremoris FC on a mouse model of dermatitis induced by repeated exposure to 2,4,6-trinitro-1-chlorobenzene

Lactococcus lactis subsp. cremoris (L. cremoris) FC is a lactic acid bacteria that produces exopolysaccharides (EPS). We studied the effects of EPS on the development of dermatitis in BALB/c mice induced by repeated exposure to 2,4,6-trinitro-1-chlorobenzene (TNCB) and on intestinal immunological activity in C3H/HeJ mice through Peyer’s patch cells. The EPS was shown to be composed of phosphopolysaccharides containing rhamnose, galactose, and glucose in a molar ratio of 1:1:3. Their weight average molecular weight (Mw) was 712,000. Oral administration of EPS suppressed skin thickening and infiltration of mast cells in skin lesions. EPS suppressed IL-4, IFN-γ, IL-6, and TNF-α overexpression caused by exposure to TNCB. Peyer’s patch cell medium cultured with EPS stimulated bone marrow cell proliferation. Together, these results suggest that EPS produced by L. cremoris FC may be an effective dietary component to prevent chronic skin inflammatory diseases.

Diospyros lotus leaf and grapefruit stem extract synergistically ameliorate atopic dermatitis-like skin lesion in mice by suppressing infiltration of mast cells in skin lesions.

Atopic dermatitis, a chronic relapsing and pruritic inflammation of the skin also thought to be involved in, or caused by immune system destruction is an upsetting health problem due to its continuously increasing incidence especially in developed countries. Mast cell infiltration in atopic dermatitis skin lesions and its IgE-mediated activation releases various cytokines and chemokines that have been implicated in the pathogenesis of atopic dermatitis. This study was aimed at investigating synergistic anti-inflammatory, anti-pruritic and anti-atopic dermatitis effects of Diospyros lotus leaf extract (DLE) and Muscat bailey A grapefruit stem extract (GFSE) in atopic dermatitis-like induced skin lesions in mice. Combinations of DLE and GFSE inhibited TNF-α and IL-6 production more than DLE or GFSE in PMA plus calcium ionophore A23187-activated HMC-1 cells. DLE and GFSE synergistically inhibited compound 48/80-induced dermal infiltration of mast cells and reduced scratching behavior than DLE or GFSE. Furthermore, DLE and GFSE synergistically showed a stronger ameliorative effect in skin lesions by reducing clinical scores; dermal infiltration of mast cells; ear and dorsal skin thickness; serum IgE and IL-4 production in atopic dermatitis-like mice. Collectively, these results suggest that DLE and GFSE synergistically exhibit anti-atopic dermatitis effects in atopic dermatitis-like skin lesions in mice.

Analysis of the presence and location of mast cells in periapical cysts and periapical granulomas

ABSTRACT Objective: The aim of the present study was to locate mast cells in chronic periapical lesions (granulomas and cysts) by using histochemical techniques and toluidine blue staining. Methods: A quantitative, descriptive, cross-sectional and retrospective research was performed. The sample was obtained from histopathological reports in the archives of the laboratory of surgical pathology of the University of Pernambuco between November 2014 and May 2015. Results: Sixteen cases of granuloma and 21 cases of periapical cysts were selected. The stained slides were analyzed by two examiners at different times, in a double-blind study. Mast cells were found in 13 (61.9%) of the periapical cyst cases, located in the capsule of the lesion. In the periapical granuloma cases, mast cells were found in eight cases (50%), located in the granulation tissue. Conclusion: Mast cells were detected in both cysts and periapical granuloma, located in the capsule and granulation tissue, respectively. Mast cells were more prevalent in periapical cysts than in periapical granuloma.

Myofibroblasts and mast cells: influences on biological behavior of odontogenic lesions.

Odontogenic lesions differ in their rate of recurrence and aggressiveness. This study aimed to evaluate the presence of myofibroblasts and mast cells in odontogenic lesions. Sample consisted of 20 cases each of dentigerous cysts, odontogenic keratocysts, and solid ameloblastomas. Histologic sections were submitted to immunohistochemistry using anti-α-smooth muscle actin and anti-tryptase antibodies. Myofibroblasts and mast cells were counted at ×400 magnification in 5 and 10 fields, respectively. Myofibroblasts were more frequent in ameloblastomas (24.41), followed by odontogenic keratocysts (16.21) and dentigerous cysts (11.85; P=.002). Granulated and degranulated mast cells were more frequent in dentigerous cysts (7.88 and 8.96, respectively), followed by odontogenic keratocysts (6.53 and 7.08) and ameloblastomas (5.21 and 1.88). The difference was only significant for degranulated mast cells (P<.05). Analysis of the correlation between myofibroblasts and mast cells (granulated and degranulated) revealed a moderate positive correlation only in ameloblastomas (R=0.621, P=.003). Probably, myofibroblasts are related to the biological behavior of the odontogenic lesions studied, particularly their aggressiveness. On the other hand, mast cells seem to be associated with inflammatory processes, which are more frequent in cystic lesions than in benign neoplasms. In addition, mast cells may induce the differentiation of fibroblasts into myofibroblasts, thus increasing the number of the latter.

Fibrosis and Mast Cells in Colorectal Lesions: Significance in Adenoma-Colorectal Cancer Sequence and Association with Diet.

Adenoma is the most common benign neoplasm with potential to progress into colorectal cancer (CRC), a disease responsible for high rates of mortality. However, it is not possible yet to establish which lesions will evolve into CRC. We aimed to investigate the intrinsic factors, diet profile, and microenvironment as factors involved in adenoma-CRC progression. We evaluated nutritional profile and microscopic features. Adenomas and CRC lesions were stained with Mallory's trichrome to reveal fibrosis and Alcian blue to identify mast cells. A total of 143 patients was selected, 66% diagnosed with normal mucosa, 28.4% with benign lesion, and 5.6% with CRC. A higher frequency of lesions was associated with patients older than 50years (26.57%) and women (18.18%), but men were more likely to develop CRC. Regarding microscopic aspects, epithelium-connective tissue interface with disorganization feature was significantly higher in CRC when compared to adenoma (P = 0.0007). A greater fibrosis around vessels was also observed in CRC (P = 0.01). The statistical analysis indicated a significant correlation between mast cell population and patients older than 50years (P < 0.01), male (P < 0.01), with right colon lesion (P < 0.05) and CRC. Low consumption of leafy greens (P < 0.001) and carotenoids (P < 0.01) and elevated consumption of red meat (P < 0.001) were associated with a high density of mast cells. An association between clinical, diet profile, and microscopic features in colorectal lesions was observed, with a progressive change in the microenvironment during adenoma-CRC sequence.

고욤잎, 감잎 및 뽕잎 복합추출물의 항아토피 효과

The present study investigated the anti-atopic effects of mixed extracts from date plum, persimmon, and mulberry leaves (DPME) on atopic dermatitis (AD)-like skin lesions in hairless mice. The in vivo results demonstrated that DPME treatment significantly reduced the dermatitis clinical score and epidermal thickness in AD-like skin lesions. Histological analyses showed that DPME treatment strongly inhibited dermal infiltration of inflammatory cells and activity of mast cells in AD-like skin lesions. DPME treatment inhibited production of serum IgE and interluekin (IL)-4 in hairless mice with AD. Moreover, DPME treatment significantly suppressed production of tumor necrosis factor (TNF)-α and IL-6 cytokines in phorbol 12-myristate 13-acetate plus calcium ionophore A23187-stimulated HMC-1 human mast cells. In addition, DPME treatment reduced production of pro-inflammatory mediators (nitric oxide, prostaglandin E2, TNF-α, and IL-6) in lipopolysaccharide-stimulated RAW 264.7 macrophages. Therefore, the results of this study indicate that the anti-atopic and anti-inflammatory effects of DPME may be involved in the regulation of inflammatory responses, suggesting that DPME may be used as an anti-atopic dermatitis material and natural anti-inflammatory ingredient.

Significance of mast cells in non-neoplastic and neoplastic lesions of uterine cervix

Background: Mast cells are involved in multiple biological events. The significance of mast cells in non-neoplastic and neoplastic lesions of cervix has been studied with conflicting results. Its presence in tumor has been described as evidence of host immunologic antitumor response, angiogenesis and tumor invasion. Aims/Objectives: To study mast cell density in various cervical lesions using Toluidine blue stain; To compare the sections studied with conventional Toluidine blue staining and Toluidine blue staining by reducing the pH. Methodology: Cervical biopsy/hysterectomy specimens from archives of Department of Pathology were considered for the study. The sections were studied for histomorphology and mast cell density. The mast cell density was assessed by Toluidine blue staining by conventional method and another method by reducing pH using weak HCL. The stained slides were reviewed for mast cell density under 10 high power field and statistically analysed. Results: Total of 100 cases were studied. Normal cervix 7 cases with mean age of 44.29 and mast cell density (mean) of 45.43. Chronic cervicitis and polypoidal Endocervicitis were 26 and 28 cases, mean age of 45.38 years and 39.14 years and mean mast cell count of 48.38 and 66.96 respectively. Intraepithelial lesions and malignancy were 23 and 16 cases, mean age of 43.56 years and 52.26 years and mean mast cell of 34.47and 34.6 respectively. Maximum number of mast cells was seen in polypoidal Endocervicitis and least number in Squamous cell carcinoma of cervix. Conclusion: The role of mast cell differs in inflammatory and neoplastic lesions of cervix. Mast cells has active role in inflammatory lesions.

Serum biomarkers and source of inflammation in acute coronary syndromes and percutaneous coronary interventions.

There is robust information that confirms the enormous contribution of inflammation to plaque development, progression and vulnerability. The presence of plaques with inflammatory components associates with a greater likelihood of future cardiovascular events. The inflammatory cascade has been implicated during the entire plaque formation, from the early stages of endothelial dysfunction to the development of acute coronary syndromes (ACS). The presence of macrophages, T lymphocytes, dendritic cells, and mast cells in atherosclerotic lesions; the detection of HLA class II antigen expression; and the finding of secretion of several cytokines point to the involvement of immune inflammatory mechanisms in the pathogenesis of atherosclerosis. Serum biomarkers reflecting the activity of biological processes involved in plaque growth or destabilization may provide great help in establishing the appropriate clinical management, and therapeutic interventions. Evidence for a role of inflammation in plaque rupture has been demonstrated by localization of inflammation at plaque rupture sites. However, the focus of inflammation may not precisely reside within the coronary vessel itself but rather in the injured myocardium distal to the disrupted plaque. These observations outline the potential benefits of therapies targeting inflammation in the arterial wall and cardiovascular system. Emerging anti-inflammatory approaches to vascular protection have the potential to benefit patients by marked reductions in serum biomarkers of inflammation and reduce vascular events. With ongoing technical advances, percutaneous coronary interventions (PCI) will continue to play a critical role in the evaluation of novel compounds designed to modulate inflammation. The constant refinements in the different therapeutic strategies, the combination of scientific understanding in the adequate utilization of novel inflammatory markers, the new pharmacologic agents, and the new techniques in PCI will ameliorate our therapeutic management in ACS based on medical evidence.

Pathogenesis of Psoriasis: A new angle with Mast cell

Background: Mast cells are bone marrow derived cells which have captured the interest of the medical fraternity since more than a century. Mast cells exhibit a constellation of biophysical functions and has been regarded as the “major cell” in inflammation and immunity. The presence of mast cells, often in an activated state or increased numbers has been noted in various cutaneous disorders. Aims and Objectives: To study the variations of mast cells in psoriatic skin lesions. To analyse the possible pathophysiological role of mast cells in psoriasis. Methods: A total of 100 cases of psoriasis were prospectively studied. Skin biopsies received in the Department of Pathology Dr. BR Ambedkar Medical College/Hospital, Bangalore were fixed in 10% formalin and routinely processed. 3-5 µ thin sections were cut and stained with Haematoxylin and Eosin. All sections were stained with Toluidine blue to selectively identify and count mast cells.10 control sections were studied. Mast cell variations in terms of morphology, distribution and count were studied in psoriasis. Mean mast cell count were calculated and statistically analysed using student’s t test. Results: Mast cells revealed a varied morphology and distribution often exhibiting an activated state and statistically significant increase (P value< 0.0001) in mast cell numbers in psoriasis when compared to the normal skin control. Conclusion: This study highlights the definitive pathophysiological contribution of mast cells in psoriasis and suggests that mast cells are of primary importance in these lesions and their presence does not merely represent a secondary event. Keywords: Mast cells, Metachromasia, Psoriasis, Mast cell profile, Toluidine blue, Student’s t test

Increased Number of Mast Cells in Atherosclerotic Lesions Correlates with the Presence of Myeloid but not Plasmacytoid Dendritic Cells as well as Pro-inflammatory T Cells.

Atherosclerosis is an inflammatory disease of the vessel wall promoted by different immune cells and inflammatory mediators. In this study, 26 human plaques and 12 control vessels without atherosclerosis were immunohistochemically stained to analyze the emergence of mast cells dependent on plaque morphology and to correlate mast cell occurrence with the emergence of myeloid as well as plasmacytoid dendritic cells. Also, mast cell emergence was correlated with the number of pro-inflammatory T cells. For this, plaques were classified as stable or unstable according to established histological criteria. As expected, atherosclerotic lesions showed significantly higher numbers of tryptase+, chymase+, and cathepsin G+ mast cells compared to control vessels, particularly in lesions with unstable morphology. As a novel finding, we detected significant correlations between mast cells and myeloid dendritic cells (fascin, CD83, r > 0.3, p < 0.01), but not plasmacytoid dendritic cells (CD123, CD304). Also, we observed significant correlations of mast cells and different subgroups of pro-inflammatory T cells (CD3, CD8, CD161, CD25; r > 0.35, p < 0.05). Overall, the higher number of mast cells in plaques, particularly with unstable morphology, suggests that mast cells might be involved in the progression of atherosclerosis. The correlation of mast cells with other immune cells that are pivotal in atherogenesis, e.g., myeloid dendritic cells and pro-inflammatory T cells, also suggests an interplay leading to plaque destabilization. Therefore, modulating local mast cell function and invasion into the plaque might be a therapeutic tool for plaque stabilization.

A Study on Evaluation of Mast Cells in Papulo-Squamous Lesions of Skin

A Study on Evaluation of Mast Cells in Papulo-Squamous Lesions of Skin

Increasing Numbers of Mast Cells in Skin Lesions of Hyperpigmented Mycosis Fungoides with Large-Cell Transformation.

Dear Editor: Mycosis fungoides (MF) is a common type of cutaneous T-cell lymphoma. In recent years, several reports have been published on an uncommon and rare form of MF: hyperpigmented MF1,2,3,4. Herein, we report a case of hyperpigmented MF and discuss the mechanisms of hyperpigmentation. A 55-year-old Japanese man presented at the dermatological outpatient clinic of our hospital for widespread, pruritic, hyperpigmented plaques. The lesions, which first appeared nearly 15 years ago, gradually developed; they were diagnosed as MF, and were subsequently treated with topical corticosteroids and/or radiation with narrow-band ultraviolet B (UVB). However, no therapeutic response was observed and small nodular lesions developed. On physical examination of the patient, we observed hyperpigmented plaques with no atrophy on the face, trunk, and extremities (Fig. 1A). We found small nodules on the back. Blood cell count, urinalysis, and serum chemistry were within normal limits. Anti-human T-cell leukemia virus type I antibody was negative. Computed tomography scan from the neck to the pelvic area was normal. Histopathological analysis of skin specimens collected from a hyperpigmented plaque on the buttocks revealed slight acanthosis with atypical lymphocytic infiltration within the epidermis and upper dermis, containing some inflammatory cells and abundant melanophages (Fig. 1B). Rearrangement of the T-cell receptor (β chain) was detected using reverse transcriptase polymerase chain reaction method, but not Southern blot analysis. Immunohistochemically, most of the atypical lymphoid cells were CD4-positive (Fig. 1C and D). We diagnosed the lesions as MF, particularly, hyperpigmented MF. After X-ray irradiation to the nodules on the back, oral retinoid plus long-wave UVA therapy was started. Although CD30 (+) large-cell transformation was found during the therapeutic course, the patient's general health and skin improved over time. Fig. 1 (A) Clinical manifestation. Hyperpigmented plaques on the trunk. (B) Histology of the lesional skin of a hyperpigmented plaque. Slight acanthosis with atypical lymphocytic infiltration within the epidermis and upper dermis, containing abundant melanophages ... So far, the etiology of hyperpigmentation in certain MF cases is not clear. Pavlovsky et al.4 reported that hyperpigmented MF was characterized by a predominantly CD8-positive phenotype. Those authors speculated that CD8-positive tumor cells could have stronger cytotoxicity and affect neighboring cells such as melanocytes or basal keratinocytes, thereby causing interface changes and marked melanin incontinence, leading to the clinical appearance of hyperpigmentation4. However, in the present case, CD4-positive cells were dominant; therefore, hyperpigmentation cannot be attributed to this hypothesis. Yamamoto et al.1 reported the association of mast cell number with hyperpigmented MF. Melanocytes are strongly stimulated by stem cell factor (SCF), which also activates the mast cells. Increasing numbers of mast cells in the skin with lesions and an upregulation of SCF in sera of hyperpigmented MF cases were found1. Thus, we compared the numbers of mast cells in the skin with lesion with normal skin controls and non-pigmented MF cases. Mast cell counts were averaged from three random fields (cells/high-power field) in toluidine blue-stained skin specimens (Fig. 1E). As shown in Table 1, compared with normal and non-pigmented MF skin, the numbers of mast cells clearly increased in skin lesions of hyperpigmented MF. Unfortunately, we did not examine the serum levels of SCF. However, the increasing numbers of mast cells suggest the existence of similar underlying mechanisms as reported by Yamamoto et al.1 Table 1 Mast cell counts in skin

Study of mast cells in prostate lesions: Adenocarcinoma compared with hyperplasia

Background: (1) To study and correlate the mast cell numbers in benign prostatic hyperplasia (BPH) and prostate carcinoma lesions. (2) To compare mast cell numbers of intratumoral and peritumoral regions in prostate adenocarcinomas. (3) To ascertain a relationship between the number of mast cells and age, prostate-specific antigen (PSA) levels, and Gleason Grade. Subjects and Methods: One-hundred cases of prostate lesions, consisting of 75 cases of BPH and 25 cases of prostatic adenocarcinoma, received in the form of transurethral resection of prostate chips in the Department of Pathology, were included in the study. After histopathological diagnosis, the paraffin sections were stained with toluidine blue. Results: The mean value of mast cell count per mm 2 in benign and malignant lesion was 37.05 and 92.20, respectively. The difference in mean mast cell count in BPH and prostatic adenocarcinoma was found to be statistically significant ( P = 0.001). The correlation between mast cell count and Gleason Grade was found to be statistically significant ( P : Grades I–III - 0.043; 0.002; 0.012). However, no correlation was found between mast cell count with age and PSA levels. Conclusion: In this study, an increase in the number of mast cells was observed in patients with prostate cancer than in benign lesions. This suggests a stimulating role of mast cells in the progression of cancer.