Panitta Sitthinamsuwan

Primary cutaneous NK/T-cell lymphoma, nasal type and CD56-positive peripheral T-cell lymphoma: A cellular lineage and clinicopathologic study of 60 patients from Asia

Primary cutaneous, extranodal natural killer/T-cell lymphoma, nasal type (PC-ENKTL), is a rare Epstein-Barr virus (EBV)-associated neoplasm with poorly defined clinicopathologic features. We performed a multinational retrospective study of PC-ENKTL and CD56-positive EBV-negative peripheral T-cell lymphoma (PC-CD56+PTCL) in Asia in an attempt to elucidate their clinicopathologic features. Using immunohistochemistry for T-cell receptors (TCRs), in situ hybridization for EBV, and TCR gene rearrangement, we classified 60 tumors into 51 with PC-ENKTL (20 of NK-cell, 17 T-cell, and 14 indeterminate lineages) and 9 with PC-CD56+PTCL. Tumors of T-cell origin accounted for 46% of PC-ENKTLs with half of these cases being TCR-silent. As compared with T-lineage tumors, PC-ENKTLs of NK-cell lineage had more frequent involvement of regional lymph nodes and more frequently CD8-negative and CD56-positive. Cases of PC-ENKTL showed more frequent tumor necrosis, younger age, and a higher frequency of CD16 and CD30 expression than cases of PC-CD56+PTCL. CD56-positive T-lineage PC-ENKTL tumors (n=8) had more localized disease in the TNM (tumor-node-metastasis) staging and were more often of &ggr;&dgr; T-cell origin compared with cases of PC-CD56+PTCL (n=9). PC-ENKTLs and PC-CD56+PTCLs were equally aggressive, with a 5-year overall survival rate of 25%. Tumor necrosis and CD16 expression may serve as useful surrogates for differentiating PC-ENKTL from PC-CD56+PTCL. A single lesion, an elevated lactate dehydrogenase level, and the presence of B symptoms were independent poor prognostic factors for PC-ENKTL in multivariate analysis. Further studies with more cases are warranted to delineate the clinicopathologic features and significance of EBV in these rare lymphomas.

A benign cutaneous plexiform hybrid tumor of perineurioma and cellular neurothekeoma.

There are several recent reports describing hybrid peripheral nerve sheath tumors showing a biphasic component of neoplastic cells. These combinations include a mixture of neurofibroma and schwannoma, schwannoma and perineurioma, neurofibroma and perineurioma, and perineurioma and granular cell tumor. A case of a triphasic combination of neurofibroma, schwannoma, and perineurioma has also been described. We describe the clinicopathologic and immunohistochemical characteristics of 9 cases of a benign cutaneous plexiform nerve sheath tumor located on the lips and exhibiting hybrid features of perineurioma and cellular neurothekeoma. Clinically, lesions were solitary dome-shaped papules located on the lips. Histopathologically, the neoplasms consisted of well-circumscribed but uncapsulated dermal nodules with a plexiform pattern. They were composed of nests or rounded aggregations of neoplastic cells embedded in a slightly myxoid stroma. Within the aggregates, cells were distributed in a storiform and lamellar pattern. Immunohistochemically, most neoplastic cells expressed strong immunoreactivity for S100A6, MiTF, NKI/C3, PGP9.5, EMA, and NSE, whereas variable, focal, and weaker positivity for CD34, claudin-1, and Glut-1 was seen in some cases. On the basis of these findings, we believe that this neoplasm is a distinctive benign cutaneous plexiform nerve sheath tumor with histopathologic and immunohistochemical hybrid features of perineurioma and cellular neurothekeoma.

Cushing’s syndrome caused by an ACTH-producing ovarian steroid cell tumor, NOS, in a prepubertal girl

Ectopic ACTH syndrome is a very rare cause of pediatric Cushing’s syndrome. And if present, bronchial or thymic carcinoids predominate as causes. We hereby demonstrate a first case report of ACTH-producing ovarian steroid cell tumor, NOS, causing ectopic ACTH syndrome in a prepubertal girl.

Progressive multifocal cerebral infarction from intravascular large B cell lymphoma presenting in a man: a case report

IntroductionIntravascular lymphoma is rare, and may present as ischemic stroke. Diagnosis is difficult due to the non-specific presentation and lack of lymphadenopathy, thus leading to frequent instances of autopsy-proven diagnosis. To the best of our knowledge, this is the first report of progressive stroke from intravascular lymphoma diagnosed antemortem by random skin biopsy.Case presentationA 42-year-old Thai man presented to our hospital with progressive multifocal cerebral infarction. Despite taking aspirin (300 mg/day), his neurological symptoms worsened. During admission, he developed an unexplained fever and hypoxemia. Magnetic resonance angiography clearly showed patency of all cerebral arteries including the internal carotid and vertebrobasilar arteries. Echocardiography, an antiphospholipid antibody test, cerebrospinal fluid cytology and a bone marrow study were normal. Other laboratory test results showed an elevated lactate dehydrogenase level, nephrotic range proteinuria (3.91 g/day), hypoalbuminemia (1.9 g/dL), a very low high-density lipoprotein level (7 mg/dL) and hypertriglyceridemia (353 mg/dL). Because of suspected vasculitis, pulse methylprednisolone was given with transiently minimal improvement. A random skin biopsy from both thighs revealed intravascular large B cell lymphoma. Chemotherapy was not given due to our patient having ventilator associated pneumonia. He died 10 days after the definite diagnosis was established.ConclusionOne etiology of stroke is intravascular lymphoma, in which random skin biopsy can be helpful for antemortem diagnosis.

An unusual case of eumycetoma caused by Exophiala jeanselmei after a sea urchin injury

Penvadee Pattanaprichakul, Sumanas Bunyaratavej, Charussri Leeyaphan, Panitta Sitthinamsuwan, Montarop Sudhadham, Chanai Muanprasart, Peiying Feng, Hamid Badali and G. Sybren de Hoog Department of Dermatology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Thailand, Department of Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, Department of Biology, Faculty of Science and Technology, Suansunandha Rajabhat University, Bangkok, Thailand, Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China, Department of Medical Mycology and Parasitology ⁄ Invasive Fungi Research Centre (IFRC), School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran and CBS-KNAW Fungal Biodiversity Centre, Utrecht, The Netherlands

A Case-Control Study of Involvement of Oxidative DNA Damage and Alteration of Antioxidant Defense System in Patients with Basal Cell Carcinoma: Modulation by Tumor Removal.

Oxidative damage has been suggested to play a role in the pathogenesis of basal cell carcinoma (BCC). This study illustrated an involvement of oxidative DNA damage and changes in antioxidant defenses in BCC by conducting a case-control study (24 controls and 24 BCC patients) and assessing urinary 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxo-dGuo), plasma antioxidant defenses including catalase (CAT), glutathione peroxidase (GPx), NQO1, and total superoxide dismutase (SOD) activities, and glutathione (GSH) levels before surgery and 1 month after surgery. 8-oxo-dGuo expressions as well as protein and mRNA expressions of DNA repair enzyme hOGG1 and antioxidant defenses (CAT, GCLC, GPx, Nrf2, and MnSOD) in nonneoplastic epidermis of control and BCC tissues were also determined. This study observed induction in urinary 8-oxo-dGuo, increased 8-oxo-dGuo expression, and reduced hOGG1 protein and mRNA in BCC tissues, decreased activities of CAT, GPx, and NQO1, but elevated SOD activities and GSH levels in BCC patients and reduction of all antioxidant proteins and genes studied in BCC tissues. Furthermore, decreased plasma antioxidant activities in BCC patients were restored at 1 month after operation compared with preoperative levels. Herein, we concluded that BCC patients were associated with oxidative DNA damage and depletion of antioxidant defenses and surgical removal of BCC correlated with improved redox status.

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

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.

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.

Two patients with rare causes of Weber's syndrome.

We report two patients with rare causes of Webers syndrome and review the relevant literature. The first patient presented with Webers syndrome caused by a partially thrombosed giant aneurysm of the posterior cerebral artery. The second patient was an immunocompetent patient who presented with progressive hemiparesis and subsequently developed Webers syndrome. Primary central nervous system lymphoma (PCNSL) was eventually diagnosed. To our knowledge, the association between Webers syndrome and PCNSL is rare.

Random Skin Biopsy in the Diagnosis of Intravascular Lymphoma

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.