Hematogenous dissemination of pulmonary mucormycosis manifested as multiple subcutaneous nodules: a case report and review of the literature.

BACKGROUND: Disseminated mucormycosis presenting with multiple subcutaneous nodules is a rare condition with a poor prognosis, and delayed diagnosis and treatment is common. CASE PRESENTATION: We report a case of 64-year-old Thai woman with colorectal cancer who initially presented with Acinetobacter baumannii pneumonia and respiratory failure. Following 10 days after her admission to the intensive care unit, she developed hospital-acquired pneumonia. Five days later, multiple subcutaneous nodules appeared on both arms and both legs. Bronchoalveolar lavage and skin biopsy cultures both grew Mucor spp. She was diagnosed with disseminated mucormycosis and was treated with liposomal amphotericin B at a dose of 5 mg/kg/day. Despite treatment, our patient succumbed to septic shock and multiorgan failure on the third day after definitive diagnosis. CONCLUSIONS: This case demonstrates that the subcutaneous nodules caused by hematogenously disseminated mucormycosis are unusual in a patient with a solid tumor. Clinicians should be aware of this atypical presentation of mucormycosis in patients with solid tumors.

Interobserver reliability of histopathological features for distinguishing between cutaneous polyarteritis nodosa and superficial thrombophlebitis.

AIMS: Interobserver reliability of histopathological features in differentiation between cutaneous polyarteritis nodosa (cPAN) and superficial thrombophlebitis (ST) by assessment of inter-rater agreement of five histological features was investigated. METHODS AND RESULTS: All sections of cPAN and ST were evaluated independently by three experienced pathologists and one resident of pathology. The histopathological features studied included elastic fibre distribution in the vascular wall, a smooth muscle arrangement pattern, an internal elastic lamina pattern, fibrinoid necrosis and luminal thrombosis. Agreement analysis was performed using the kappa coefficient. Sensitivity, specificity, positive predictive value (PPV), positive likelihood ratio (PLR) and 95% confidence interval (95% CI) of the useful histopathological features were analysed. Of all 62 biopsies, 28 were cPAN and 34 were ST. Reproducibility between four observers was in substantial agreement (κ = 0.73). Elastic fibre distribution in the vascular wall (κ = 0.68), fibrinoid necrosis (κ = 0.63), an internal elastic lamina pattern (κ = 0.51) and a smooth muscle arrangement pattern (κ = 0.46) showed high specificity and PPV for differentiating between cPAN and ST. The smooth muscle arrangement pattern, internal elastic lamina pattern and elastic fibre distribution in the vascular wall may be obscured when extensive inflammation and necrosis occurs. CONCLUSIONS: These aforementioned histopathological features are useful in differentiation between cPAN and ST. The Verhoeff-van Gieson (VVG) elastic stain is an important histochemical study for differentiating between cPAN and ST, particularly in cases with extensive inflammation and necrosis.

Subcutaneous Panniculitis-Like T-Cell Lymphoma Versus Lupus Erythematosus Panniculitis: Distinction by Means of the Periadipocytic Cell Proliferation Index.

The distinction between subcutaneous panniculitis-like T-cell lymphoma (SPTCL) and lupus erythematosus (LE) panniculitis is remarkably challenging. Rimming by lymphocytes with an elevated Ki-67 cell proliferation index has been forwarded as a potential diagnostic finding in biopsies of SPTCL but has not been rigorously compared with biopsies from patients with LE panniculitis. Nineteen and 17 examples of SPTCL and LE panniculitis, respectively, were evaluated for periadipocytic rimming by lymphocytes expressing Ki-67, CD8, and ßF1 and for attributes associated with LE, including clusters of CD123-positive cells. The identification of periadiopocytic rimming using Ki-67, CD8, and ßF1 held sensitivity of 79%, 100%, and 89.5% and specificity of 100%, 52.9%, and 88.2%, respectively (P < 0.01). CD123-positive cells were in both disorders. LE-like histopathology was commonly encountered in SPTCL. In conclusion, an elevated Ki-67 cell proliferation index with rimming is useful for distinguishing SPTCL from LE panniculitis. Notably, many features of LE panniculitis can also be encountered in SPTCL.

Random skin biopsy in the diagnosis of intravascular lymphoma.

BACKGROUND: Random skin biopsy (RSB) is a method for diagnosis of intravascular lymphoma (IVL). However, the indications for RSB to diagnose IVL have not yet been established. The aim of this study was to determine the appropriate indications for RSB to diagnose IVL. METHODS: Thirty-two patients with fever of unknown origin (FUO) and without skin lesion underwent RSB for diagnosis of IVL. Clinical data, including fever, neurological symptoms, hematologic disorders, organomegaly, bone marrow (BM) study, hypoxemia and serum level of lactate dehydrogenase (LDH), were evaluated. RESULTS: Seven of 32 patients were definitively diagnosed with IVL. In addition to FUO, 2 IVL patients also suffered from dyspnea and neurological disorders. Patients who had FUO with accompanying hematologic disorders, high LDH, negative BM study and no lymphadenopathy or hepatosplenomegaly had a significant tendency to have IVL by RSB (P = .03). FUO with hypoxemia was also identified as a significant indication for RSB (P = .02). CONCLUSIONS: RSB is a reliable method for diagnosis of IVL, especially in patients with FUO and any 1 or more of the 4 following abnormalities: (1) hematologic abnormalities; (2) high serum LDH; (3) hypoxemia; and/or, (4) unusual neurological symptoms with co-existing hematologic abnormalities and without lymphadenopathy, hepatosplenomegaly or BM abnormality.

The effect of pre-operative topical anaesthetic cream on the ablative width and coagulative depth of ablative fractional resurfacing laser.

Topical anaesthetic cream (TAC) is commonly used as a pre-treatment of ablative fractional resurfacing (AFR) laser. Most of anaesthetic cream contains distilled water as major component. Therefore, pre-operative TAC may interfere the photothermal reaction in the skin treated with fractional carbon-dioxide (FCO2) laser and fractional erbium-doped yttrium aluminium garnet (FEr:YAG) laser. The objective of the study was to compare the ablative width (AW) and coagulative depth (CD) of AFR laser with and without pre-treatment with TAC. Four Thai females who underwent abdominoplasty were included in the study. The excised skin of each subject was divided into four areas. TAC (eutectic mixture of local anaesthesia; EMLA) with 1-h occlusion was applied only on the first and second areas. The first and third areas were treated with FCO2 at 15 mj and 5% density. The second and fourth areas were treated with FEr:YAG at 28 J/cm2 and 5% density. Six biopsied specimens were obtained from each area. A total of 96 specimens (24 specimens from each area) were collected from four patients and examined randomly by two dermatopathologists. The ablative width and coagulative depth from each specimen were determined. In FCO2-treated specimens, the mean AW of the specimens that were pre-treated with TAC and control was 174.86 ± 24.57 and 188.52 ± 41.32 µm. The mean CD of the specimens that were pre-treated with TAC and control was 594.96 ± 111.72 and 520.03 ± 147.40 µm. There were no significant differences in AW and CD between both groups (p = 0.53 and p = 0.15). In FEr:YAG-treated specimens, the mean AW of the specimens that were pre-treated with TAC and control was 381.11 ± 48.02 and 423.65 ± 60.16 µm. The mean CD of the specimens that were pre-treated with TAC and control was 86.03 ± 29.44 and 71.59 ± 18.99 µm. There were no significant differences in AW and CD between both groups (p = 0.16 and p = 0.24). The pre-treatment with TAC provided no statistically difference from the control group on AW and CD of both FCO2 and FEr:YAG laser irradiation. However, there was a tendency to have narrower AW and deeper CD of the areas that were pre-treated with TAC when comparing to that of the control.

Immune response in human chromoblastomycosis and eumycetoma - focusing on human interleukin-17A, interferon-gamma, tumour necrosis factor-alpha, interleukin-1 beta and human beta-defensin-2.

Knowledge regarding host immune response to chromoblastomycosis and eumycetoma is limited, particularly concerning cytokines and antimicrobial peptides production. This was a retrospective study of 12 paraffin-embedded tissue samples from patients diagnosed with chromoblastomycosis or eumycetoma from histological findings and tissue culture. DNA extraction and polymerase chain reaction (PCR) from tissues were done to evaluate human interleukin-17A (IL-17A), interferon-gamma (IFN-γ), tumour necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß) and human beta-defensin-2 (HBD-2) expressions. Human beta-actin primer was used for confirming DNA detection, and DNA extracted from psoriasis lesional skin samples was used as positive controls. The twelve paraffin-embedded sections used in this study consisted of five chromoblastomycosis and seven eumycetoma tissues. All PCR reactions showed beta-actin band at 51 bp in all clinical specimens, confirming adequate DNA levels in each reaction. As positive control, the psoriasis skin samples revealed bands for IL-17A at 174 bp, IFN-γ at 273 bp, TNF-α at 360 bp, IL-1ß at 276 bp and HBD-2 at 255 bp. For the chromoblastomycosis and eumycetoma tissues, PCR analyses showed IL-17A band at 174 bp in two eumycetoma tissues and HBD-2 band at 255 bp in a chromoblastomycosis tissue. This study demonstrated IL-17A expression in human eumycetoma and HBD-2 expression in human chromoblastomycosis for the first time. However, their role in immune response remains to be elucidated.

Histiocytoid neutrophilic dermatitis, an unusual histopathology in neonatal lupus erythematosus.

The authors reported histiocytoid neutrophilic dermatitis in neonatal lupus erythematosus (NLE). One-month-old male infant presented with annular erythematous plaques at the face and trunk. Serologic studies revealed positive anti-ribonuclear protein antibodies (RNP) and antinuclear antibodies (ANA). Histopathology showed predominant myeloid lineage mononuclear cells admixed with segmented neutrophils. This finding is uncommon in cutaneous NLE. Cutaneous NLE and LE should be included in the differential diagnosis of histiocytoid neutrophilic dermatitis. Additional immunohistochemistry studies with clinical and serologic correlations are important to differentiate histiocytoid neutrophilic dermatitis from the other diagnoses, especially leukemic cutis in young patients.

SOX-10 and MiTF expression in cellular and 'mixed' neurothekeoma.

BACKGROUND: Neurothekeoma and nerve sheath myxoma have long been interpreted as related tumors that share nerve sheath linage. Lack of S100 expression in neurothekeoma and similarities of gene expression profiles between neurothekeoma and fibrohistiocytic tumors have created reasonable doubt about this concept. SOX-10 represents a marker for schwannian and melanocytic differentiation, and is expressed in other tumors of nerve sheath linage. Microphthalmia transcription factor (MiTF) expression has been repeatedly reported in cellular neurothekeoma in the recent literature and was proposed as a helpful marker in this entity. METHODS: We investigated 25 cases of cellular neurothekeoma, 8 cases of mixed neurothekeoma and 1 case of nerve sheath myxoma for the expression of SOX-10, MiTF, S100, NKI/C3, Melan-A and smooth muscle actin (SMA) using immunohistochemistry. RESULTS: A lack of SOX-10 expression was demonstrated in 100% of cellular and mixed neurothekeomas, but was present in the case of nerve sheath myxoma. More than two thirds of neurothekeomas showed very focal or no reactivity with MiTF. CONCLUSIONS: Our data suggest that neurothekeoma and nerve sheath myxoma are unrelated, and that cellular and mixed neurothekeoma may not be of nerve sheath lineage. In addition, MiTF should not be regarded as a useful marker in neurothekeoma.

Severe Cutaneous Manifestation of Malignant Syphilis in a Patient with Behçet's Uveitis: A Case Report.

Introduction: Syphilis exhibits a wide range of clinical presentations, mimicking various systemic and ocular diseases. Ocular syphilis, in particular, manifests with multiple presentations, ranging from anterior uveitis to panuveitis, making it a potential differential diagnosis for Behçet's uveitis. Here, we present a unique case of Behçet's panuveitis that was undergoing immunomodulatory therapy and was complicated by ocular syphilis. Notably, this case also featured rare cutaneous manifestations associated with secondary syphilis, commonly known as malignant syphilis. Case Presentation: A 38-year-old Thai man with refractory end-stage Behçet's panuveitis reported a maculopapular rash accompanied by increased intraocular inflammation. The escalation of immunomodulatory therapy, intended to manage the provisional diagnosis of active ocular and cutaneous Behçet's disease, resulted in clinical deterioration, with the rash transforming into multiple noduloulcerative lesions. Despite negative serologic tests for syphilis at baseline before initiating immunomodulatory therapy, syphilis infection was eventually diagnosed following reevaluation and the observation of spirochetes in a skin biopsy specimen. The patient was treated with intravenous penicillin G, resulting in an improvement in intraocular inflammation and resolution of noduloulcerative rashes. Conclusion: Intraocular inflammation and mucocutaneous lesions in syphilis can mimic the presentation of Behçet's disease. The introduction of immunomodulatory therapy may alter the clinical picture, leading to a severe and atypical presentation. A high index of suspicion for reevaluating serologic tests or performing tissue biopsies is warranted for an accurate diagnosis.

Integrated Histological and Molecular Analysis of Filarial Species and Associated Wolbachia Endosymbionts in Human Filariasis Cases Presenting Atypically in Thailand.

Atypical presentations of filariasis have posed diagnostic challenges due to the complexity of identifying the causative species and the difficulties in both diagnosis and treatment. In this study, we present the integrative histological and molecular analysis of seven atypical filariasis cases observed in regions of nonendemicity of Thailand. All filariasis cases were initially diagnosed based on histological findings. To confirm the causative species, molecular characterization based on both filarial mitochondrial (mt 12S rRNA and COI genes) and nuclear ITS1 markers was performed, together with the identification of associated Wolbachia bacterial endosymbionts. Among the cases studied, Brugia pahangi (N = 3), Brugia malayi (N = 1), Dirofilaria sp. "hongkongensis" (N = 2), and a suspected novel filarial species genetically related to Pelecitus copsychi (N = 1) were identified. By targeting the 16S rRNA gene, Wolbachia was also molecularly amplified in two cases of infection with Dirofilaria sp. "hongkongensis." Phylogenetic analysis further revealed that the detected Wolbachia could be classified into supergroups C and F, indicating the high genetic diversity of this endosymbiont in Dirofilaria sp. "hongkongensis." Furthermore, this study demonstrates the consistency between histological findings and species identification based on mitochondrial loci rather than on the nuclear ITS1. This suggests the utility of mitochondrial markers, particularly COI, as a highly sensitive and reliable diagnostic tool for the detection and differentiation of filarial species in clinical specimens. Precise identification of the causative species will facilitate accurate diagnosis and treatment and is also essential for the development of epidemiological and preventive strategies for filariasis.

Neuroendocrine carcinomas of the uterine cervix: A clinicopathological study.

BACKGROUND: Neuroendocrine carcinoma (NEC) is a rare entity of uterine cervical carcinoma. Most of them have a more aggressive course and worse prognosis than a common type squamous cell carcinoma. Therefore, precise diagnosis is very crucial. OBJECTIVE: To study clinicopathological correlation and immunohistochemistry of uterine cervical NEC MATERIAL AND METHOD: All primary uterine cervical carcinomas from a 51-month period were histopathologically reviewed. Suspicious NECs were retrieved and immunohistochemically studiedfor chromogranin, synaptophysin, non-specific esterase (NSE) and CD56. Clinical information including treatments and mean disease free survival time were obtainedfrom chart review RESULTS: Fourteen (3.5%) cases of NEC were identified from 389primary uterine cervical carcinomas between October 1, 2002 and December 31, 2006 and classified into small cell neuroendocrine carcinoma (SNEC, 8 cases), large cell neuroendocrine carcinoma (LNEC, 3 cases), mixed SNEC and adenocarcinoma (2 cases), and mixed SNEC anid squamous cell carcinoma (1 case). All NEC presented with abnormal vaginal bleeding. The median age was 44 years (34-75 years). Exophytic mass was noted in 11 patients (78.6%). Five patients (36%) had distant metastases. All cases were immunoreactive for at least two neuroendocrine markers. Nine cases (64.3%) were positive for chromogranin, 11 (78.6%) for synaptophysin, 12 (85. 7%) for NSE, and 11 (78.6%) for CD56. CD56 was positive in eight of 11 SNEC cases. The mean disease free interval and overall survival time were 17.5 and 23.9 months, respectively CONCLUSION: Neuroendocrine carcinoma of the cervix is rare and has poor prognosis. In addition to histopathology, panel ofimmunohistochemistry is mandatory in the diagnosis of neuroendocrine carcinoma. Varying results of immunohistochemistry may be found.

Generalized granuloma annulare presenting with lesions resembling eruptive xanthoma.

Generalized granuloma annulare (GGA) and eruptive xanthoma are dermatological diseases that occasionally share some clinical and histological similarities. Associated underlying medical conditions and clinical course are essential guides to the proper diagnosis. The authors reported a case ofdisseminatedyellowish-redpapules in a 24-year-old female with high levels of serum fasting blood sugar triglycerides, and cholesterol. The provisional diagnosis was eruptive xanthoma but histopathology and immunoperoxidase study revealed granuloma annulare. The remission of the skin lesions soon after control of dyslipidemia and diabetes mellitus is not typical for the usual GGA, which has a chronic relapsing course and a poor response to treatment. Further studies are required to differentiate these two entities when they come into the clinicopathological mimicry.

Cutaneous and mucosal mucormycosis mimicking pancreatic panniculitis and gouty panniculitis.

BACKGROUND: Histopathologic study of lesions of cutaneous mucormycosis usually shows suppurative granulomas involving the deep dermis and subcutaneous fat. Large, broad and non-septate fungal hyphae are easily identified within the necrotic areas. OBJECTIVE: The main goal of our study is to describe the histopathologic features of 13 cases of cutaneo-mucous mucormycosis, which mimicked the findings of pancreatic and/or gouty panniculitis and discuss the histopathologic differential diagnosis among these 3 disorders. METHODS: Histopathologic examination of sections stained with hematoxylin-eosin, periodic acid-Schiff (PAS), Gomori methenamine, and Grocott stains. All sections were examined under polarized light. One case was immunohistochemically studied with anti-BCG antibody. RESULTS: Histopathologically, the most striking feature consisted of the presence of groups of necrotic adipocytes lacking nuclei and large cytoplasm with pale basophilic hue due to calcium salts deposition. In other areas, groups of necrotic adipocytes filled with radially oriented needle-shaped and slightly eosinophilic crystals were seen. These intracellular crystals were refractile under polarized light examination. Numerous thick-walled non-septate fungal hyphae scattered throughout the necrotic areas were also seen in all cases. LIMITATIONS: The study was limited to 13 cases. CONCLUSIONS: Histopathologic study of 13 cases of subcutaneous mucormycosis demonstrated features closely resembling those of pancreatic panniculitis and/or gouty panniculitis. Ghost adipocytes should be not considered as diagnostic of pancreatic panniculitis and necrotic adipocytes containing needle-shaped refractile crystals should be not interpreted as specific of gouty panniculitis.

Cutaneous Involvement of Extranodal NK/T Cell Lymphoma, Nasal Type, a Clinical and Histopathological Mimicker of Various Skin Diseases.

BACKGROUND: Extranodal NK/T cell lymphoma, nasal type (ENK/T) with cutaneous involvement has various histopathological findings and diverse clinical manifestations. METHODS: A retrospective study of cutaneous involvement of ENK/T lymphoma between 2006 and 2018 was conducted. RESULTS: Twenty-two cases were eligible for this study. Twelve cases could be proven as secondary cutaneous involvement by ENK/T lymphoma, while the remaining could not be confirmed as primary cutaneous ENK/T lymphoma. The histopathological patterns included dermal and subcutaneous nodular infiltration pattern in 11/22 cases (50%), lobular panniculitis pattern in 6/22 cases (27.3%), interface dermatitis pattern in 4/22 cases (18.2%), and granulomatous dermatitis pattern in 1/22 case (4.5%). The median follow-up was 18.3 months. Overall, the one-year and five-year survival rates were 31.3% and 13.3%, respectively. CONCLUSIONS: A variety of histopathological patterns of cutaneous involvement by ENK/T lymphoma should be differentiated from other cutaneous lymphomas, dermatitis, and infection. When atypical medium or large-sized lymphoid cells are encountered within skin lesions, pathologists should realize these lesions can be ENK/T lymphoma, especially in cases with coexisting tumor necrosis or angioinvasion. A complete evaluation of the upper aerodigestive tract is mandatory to identify the occult primary site of ENK/T lymphoma before establishing primary cutaneous ENK/T lymphoma.

Clinical Clues to Differentiate between Dermatophyte Onychomycosis (DP-OM) and Dermatophytoma-Like Traumatic Onychodystrophy (DP-TO).

Background: Dermatophytoma is a recalcitrant condition of onychomycosis (OM). It presents as a white- or yellow-colored fungal mass that appears linear/triangular or round on a nail plate. Traumatic onychodystrophy (TO) can present with dermatophytoma-like lesions. Typically, OM and TO are not clinically distinguishable. Mycological testing is the gold standard for differentiating these disorders. Objectives: This study is aimed at differentiating between the clinical and dermoscopic factors related to dermatophytoma onychomycosis (DP-OM) and dermatophytoma-like traumatic onychodystrophy (DP-TO). Methods: A retrospective study was conducted of patients with dermatophytoma-like nail lesions who visited the Siriraj Nail Clinic between January 2010 and July 2020. The diagnosis of DP-OM was made by direct microscopy, fungal cultures, and histopathology of nail clippings. Results: A total of 36 nails were included in the study. Thirteen nails were DP-OM, and 23 nails were DP-TO. The demographic data and risk factors for the 2 groups were not significantly different. Dermatophytoma lesions were found on the lateral side of nails in 12 cases of DP-OM (92.3%) and 11 cases of DP-TO (47.8%; P = 0.008). DP-OM was associated with longitudinal striae adjacent to dermatophytoma (69.2% vs. 30.4%; P = 0.024), sulfur-nugget-like subungual debris (23.1% vs. 0%; P = 0.040), and scale on the ipsilateral foot (69.2% vs. 8.7%; P < 0.001). DP-TO was associated with a homogenous, whitish discoloration (47.8% vs. 7.7%; P = 0.014) and a sharp edge of the onycholytic area (43.5% vs. 0%; P = 0.005). Conclusions: The lateral location of dermatophytoma, adjacent striae, sulfur-nugget-like debris, and scale on the ipsilateral foot were significantly associated with DP-OM. Dermoscopic examination (dorsal and hyponychium views) and foot examination are beneficial for distinguishing between DP-OM and DP-TO.

Cutaneous involvement by colonic extranodal NK/T-cell lymphoma mimicking mycosis fungoides: a case report*.

We report a 51-year-old woman with cutaneous involvement by extranodal NK/T-cell lymphoma (TCL) of the colon that microscopically mimicked mycosis fungoides (MF). She had a history of fever of unknown origin for 2 months and then developed multiple erythematous papules on her trunk and extremities. A skin biopsy revealed superficial infiltration by atypical small to medium-sized lymphocytes with epidermotropism and Pautrier collections. Immunohistochemical studies showed expression of CD3 and TIA-1 with lack of expression (double negative) of CD4 and CD8. Initially, we reported the diagnosis as MF, cytotoxic variant. Thereafter, computerized tomography scan incidentally identified a colonic mass. A colonic biopsy revealed infiltration of atypical lymphoid cells with the same morphology and immunophenotype as those found in the skin. Additionally, CD56 and Epstein-Barr virus-encoded RNA in situ hybridization in both skin and colonic biopsies were diffusely positive. Thus, extranodal NK/TCL was diagnosed. Delta T-cell receptor (TCR) gene rearrangement was documented in the skin biopsy by polyacrylamide gel electrophoresis and fluorescence capillary gel electrophoresis methods. There was no TCR gene rearrangement detected in the colonic biopsy. Unfortunately, the patient died within 2 months of diagnosis.

Granulomatous mycosis fungoides with large cell transformation misdiagnosed as leprosy.

BACKGROUND: Granulomatous mycosis fungoides is an unusual histopathological variant of cutaneous T-cell lymphoma without clinical distinction from classic mycosis fungoides. Symptoms associated with peripheral nerve involvement have rarely been reported in the literature. CASE REPORT: The authors described a case of granulomatous MF stage IIB with large cell transformation who initially presented with leprosy-like condition and chronic left peroneal neuropathy The patient received six courses ofgemcitabine with greater than 90% improvement of skin lesions. The rest of the lesions were successfully treated with local electron beam radiation. CONCLUSION: Granulomatous MF with neuropathy can be clinically misdiagnosed if there is no histopathological and immunohistochemical finding to support the diagnosis of lymphoma.

Extranodal NK/T cell lymphoma, nasal type, presenting with primary cutaneous lesion mimicking granulomatous panniculitis: a case report and review of literature.

BACKGROUND: Cutaneous extranodal NK/T-cell lymphoma, nasal type (NK/T) is relatively rare, associated with aggressive behavior and poor prognosis. Histopathological findings, immunohistochemical study and EBV-encoded RNA (EBER) in situ hybridization are essential for the diagnosis. CASE REPORT: A 54-year-old Thai man with NK/T of the nasal cavity initially presented with cutaneous NK/T mimicking granulomatous panniculitis. The skin biopsies were performed twice due to the marked necrosis in the first one. The second biopsy revealed small, medium, and large atypical lymphoid cells infiltrating fat lobules with necrotic foci and granulomatous reaction. Within the granulomatous inflammation, the atypical lymphoid cells showing involvement of the blood vessel (angiocentricity) were noted. Immunostaining demonstrated that the atypical lymphoid cells marked with CD3, CD56, and TIA-1, but they did not mark with CD5, CD20, CD15, or CD30. EBER in situ hybridization was positive. CONCLUSION: Cutaneous NK/T can produce granulomatous panniculitis. The recognition of atypical lymphoid cells showing angiocentricity together with immunohistochemistry and EBER in situ hybridization are crucial for the correct diagnosis.

Synthetic hair reactions and treatment of complications: Case reports.

BACKGROUND: Synthetic hair fiber implantation first achieved widespread use in the 1970s, but in 1983, the US Federal Drug Administration banned the fibers due to its complications. Currently available synthetic fibers consist of polyamide material, which has been claimed to be effective and safe. Nevertheless, its use for hair restoration is controversial because of complications such as recurrent infections; the rejection and the faster-than-anticipated loss of fibers; frequent allergic reactions; fears about carcinogenicity; cicatricial alopecia; granulomatous hypersensitivity; and cyst formation. AIMS: To report complications of synthetic hair implantation and treatments. METHODS: We report the clinical data, pathological studies, and treatment outcomes of two patients who developed complications after a synthetic hair implantation. RESULTS: Our case reports showed significant moderate-to-severe adverse events, including recurrent folliculitis, scalp crusting, scarring, the matting and breakage of fibers, and granulomatous reactions. The onset of the reactions varied between 1 and 8 weeks. Pathological studies showed that the implantation of the synthetic hair into the scalp produced a hyperplastic proliferation of epidermal cells, foreign body granuloma, and persistent acute inflammation due to bacterial infections. In our study, definitive treatment was ineffective until the synthetic fibers were removed from the scalp. CONCLUSION: These significant adverse reactions may limit the benefits of synthetic hair fiber implantation for some patients. Although the inflammations were initially controlled by oral and topical antibiotics, a variety of antibiotics were unable to control the folliculitis. The fibers were ultimately removed, following which, the inflammations improved.

Ki-67 and p16 Immunostaining Differentiates Pagetoid Bowen Disease From "Microclonal" Seborrheic Keratosis.

OBJECTIVES: We observed keratoses with "clonal" nests present as numerous tiny collections, in which cells in "pagetoid" array are found, a configuration we termed microclonal seborrheic keratosis (MSK). To better distinguish MSK from pagetoid Bowen disease (PBD), we investigated use of immunohistochemical staining. METHODS: Biopsy specimens of 26 MSKs, 17 PBDs, and 11 borderline cases were reviewed for histopathology and stained with p53, Ki-67, and p16. RESULTS: High expression of Ki-67 and p16 was observed in 12 (80%) of 15 PBDs and in one (4%) of 23 MSKs. Low expression of p16 and high expression of Ki-67 were observed in 16 (70%) of 23 MSKs and in two (13%) of 15 PBDs. Expression of p16 was elevated in 12 (80%) of 15 PBDs and in three (13%) of 23 MSKs (P < .0001). CONCLUSIONS: We describe a "microclonal" variant of seborrheic keratosis with morphology sometimes challenging to distinguish from PBD. High expression of p16 and Ki-67 or p16 alone favors the diagnosis of PBD over MSK.