Glycogen-rich pleomorphic xanthoastrocytoma with clear-cell features: confirmatory report of a rare variant with implications for differential diagnosis

Central nervous system space-occupying lesions with clear-cell features encompass a nosologically heterogeneous array, ranging from reactive histiocytic proliferations to neuroepithelial or meningothelial neoplasms of various grades and to metastases. In the face of such differential diagnostic breadth, recognizing cytoplasmic lucency as part of the morphological spectrum of some low grade gliomas will directly have an impact on patient care. We describe a prevailing clear-cell change in an epileptogenic left temporal pleomorphic xanthoastrocytoma surgically resected from a 36-year-old man. Mostly subarachnoid and focally calcified, the tumor was composed of fascicles of moderately atypical spindle cells with optically lucent cytoplasm that tended to intermingle with a desmoplastic mesh of reticulin fibers. Immunohistochemically, coexpression of S100 protein, vimentin, GFAP, and CD34 was noted. Conversely, neither punctate staining for EMA nor positivity for CD68 was seen. Mitotic activity was absent, and the MIB1 labeling index was 2-3% on average. Diastase-sensitive PAS-positive granula indicated clear-cell change to proceed from glycogen storage. Electron microscopy showed tumor cell cytoplasm to be largely obliterated by non-lysosomal-bound pools of glycogen, while hardly any fat vacuole was encountered. Neither ependymal-derived organelles nor annular lamellae suggesting oligodendroglial differentiation were detected. The latter differential diagnosis was further invalidated by lack of codeletion of chromosomal regions 1p36 and 19q13 on molecular genetic testing. By significantly interfering with pattern recognition as an implicit approach in histopathology, clear-cell change in pleomorphic xanthoastrocytoma is likely to suspend its status as a "classic", and to prompt more deductive differential diagnostic strategies to exclude look-alikes, especially clear-cell ependymoma and oligodendroglioma.

Radiographic technique and anatomy of the equine sacroiliac region

Radiography is part of evaluating horses with poor performance and pelvic limb lameness; however, the radiographic appearance of the sacroiliac region is poorly described. The goal of the present study was to describe the use of a simple technique to obtain radiographs of the sacroiliac region in the anesthetized horse and to describe the radiographic appearance of this region. Seventy-nine horses underwent radiography of the pelvis under general anesthesia in dorsal recumbency. During a 5s exposure time the horse was actively ventilated to blur the abdominal viscera, which allowed assessment of individual bone structures in 77 horses. A large variation in the shape of the sacral wings, their articulation with the transverse processes of L6, and the relation of the sacrum to the ilium were observed. Females had significantly narrower width of the sacral wings. Broad sacral wings and bony proliferations at the caudal aspect were commonly observed features and their size was highly correlated with gender. In males, caudal osteophytes were significantly larger than in females. Five horses had transitional or hemitransitional vertebrae. Radiography with the ventilation-induced blurring technique is a simple approach that results in diagnostic quality radiographs and delineation of the highly variable bone structures of the sacroiliac region.

Expression of TCL1 in hematologic disorders

OBJECTIVE: TCL1, MTCP1 and TCL1b are three members of a new family of oncogenes that are expressed in T cell leukemias of ataxia telangiectasia patients (T-PLL, T-CLL). TCL1 is located at 14q32.1 and activated by juxtaposition to the alpha/delta-locus at 14q11 or beta-locus at 7q35 of the T cell receptor during the reciprocal translocations t(14;14)(q11;q32), t(7;14)(q35;q32), or inversion inv(14)(q11;q32). TCL1 encodes a predominantly cytoplasmic protein of 114 aa (14 kD) of unknown function. Recent studies suggest that TCL1 promotes cell survival rather than stimulating cell proliferation, as previously proposed. METHODS: In an attempt to clarify the contexts in which TCL1 is expressed, we investigated TCL1 expression in 114 lymphoma and leukemia patients by Northern blot, RT-PCR and immunohistochemistry. RESULTS: TCL1 expression is restricted to lymphoid cells, and is found in neoplastic (T and B cell neoplasms, and Hodgkin's disease) and nonneoplastic proliferations (reactive lesions). Out of 114 cases, 18 neoplasms of myeloid and 4 cases of epithelial origin were TCL1-negative. In lesions of the lymphoid system, both low- and high-grade lymphomas were found to express TCL1. CONCLUSIONS: We propose that TCL1 expression especially in high-grade B cell non-Hodgkin's lymphomas might interfere with B cell differentiation and promote the transition from low- to high-grade lymphoma.

Primary cutaneous CD4+ small-/medium-sized pleomorphic T-cell lymphoma: a cutaneous nodular proliferation of pleomorphic T lymphocytes of undetermined significance? A study of 136 cases

Patients with skin nodules characterized by the infiltrate of pleomorphic small/medium T lymphocytes are currently classified as "primary cutaneous CD4+ small-/medium-sized pleomorphic T-cell lymphoma" (SMPTCL) or as T-cell pseudolymphoma. The distinction is often arbitrary, and patients with similar clinicopathologic features have been included in both groups. We studied 136 patients (male:female = 1:1; median age: 53 years, age range: 3-90 years) with cutaneous lesions that could be classified as small-/medium-sized pleomorphic T-cell lymphoma according to current diagnostic criteria. All but 3 patients presented with solitary nodules located mostly on the head and neck area (75%). Histopathologic features were characterized by nonepidermotropic, nodular, or diffuse infiltrates of small- to medium-sized pleomorphic T lymphocytes. A monoclonal rearrangement of the T-cell receptor-gamma gene was found in 60% of tested cases. Follow-up data available for 45 patients revealed that 41 of them were alive without lymphoma after a median time of 63 months (range: 1-357 months), whereas 4 were alive with cutaneous disease (range: 2-16 months). The incongruity between the indolent clinical course and the worrying histopathologic and molecular features poses difficulties in classifying these cases unambiguously as benign or malignant, and it may be better to refer to them with a descriptive term such as "cutaneous nodular proliferation of pleomorphic T lymphocytes of undetermined significance," rather than forcing them into one or the other category. On the other hand, irrespective of the name given to these equivocal cutaneous lymphoid proliferations, published data support a nonaggressive therapeutic strategy, particularly for patients presenting with solitary lesions.

Solitary small- to medium-sized pleomorphic T-cell nodules of undetermined significance: clinical, histopathological, immunohistochemical and molecular analysis of 26 cases

BACKGROUND: Solitary skin nodules composed of pleomorphic T lymphocytes are often the source of diagnostic problems. OBJECTIVE: To characterize the clinicopathological features, prognosis and optimal treatment modalities of patients with solitary lymphoid nodules of small- to medium-sized pleomorphic T lymphocytes. METHODS: Twenty-six patients were analysed for clinical, histopathological, immunophenotypical, molecular and follow-up data. Results: Lesions were located mainly on the head and neck (n = 16; 61.5%) or trunk (n = 8; 30.8%). Histopathology showed non-epidermotropic nodular or diffuse infiltrates of small- to medium-sized pleomorphic T lymphocytes. Monoclonality was found by PCR in 54.2% of cases (n = 13/24). After a mean follow-up of 79.7 months, a local recurrence could be observed only in 1 patient. CONCLUSIONS: Our patients have a specific cutaneous lymphoproliferative disorder characterized by reproducible clinicopathological features. The incongruity between the indolent clinical course and the worrying histopathological features poses difficulties in classifying these cases unambiguously as benign or malignant. We suggest to describe these lesions as 'solitary small- to medium-sized pleomorphic T-cell nodules of undetermined significance'. Irrespective of the name given to these equivocal cutaneous lymphoid proliferations, follow-up data support a non-aggressive therapeutic strategy.

Cutaneous reactive angiomatosis with combined histological pattern mimicking a cellulitis

Cutaneous reactive angiomatoses (CRA) encompass a distinct group of rare benign reactive vascular proliferations that include reactive angioendotheliomatosis, diffuse dermal angiomatosis and reactive intralymphatic histiocytosis. The etiology of these conditions, often associated with either localized or systemic diseases, is poorly understood. We report a 72-year-old woman who presented giant diffuse cellulitis-like plaques on the right lower limb and the pelvis and a reduction of her general condition with fever. Light microscopy studies revealed combined features of reactive angioendotheliomatosis, diffuse dermal angiomatosis and reactive intralymphatic histiocytosis. A small arteriovenous fistula of the right lower leg was thought to act as trigger. Systemic corticosteroids resulted in the clinical remission of the skin lesions. Our observation provides strong evidence that reactive angioendotheliomatosis, diffuse dermal angiomatosis and reactive intralymphatic histiocytosis, previously regarded as distinct forms of CRA, may show overlapping histopathological features and most likely represent facets of the same disease.

Malignant nail tumors

Because of the large number of different tissues making up the distal phalanx of fingers and toes, a large variety of malignant tumors can be found in and around the nail apparatus. Bowen disease is probably the most frequent nail malignancy. It is usually seen as a verrucous plaque of the nail fold and nail bed in persons above the age of 40 years. It slowly grows over a period of years or even decades before degenerating to an invasive squamous cell carcinoma. The latter may also occur primarily often as a weeping onycholysis. The next most frequent nail malignancy is ungual melanoma. Those arising from the matrix are usually pigmented and often start with a longitudinal melanonychia whereas those originating from the nail bed remain amelanotic, are often nodular and mistaken for an ingrown nail in an elderly person. The treatment of choice for in situ and early invasive subungual melanomas is generous extirpation of the nail apparatus whereas distal amputation is only indicated for advanced melanomas. In addition to these frequent nail malignancies, nail-specific carcinomas, malignant vascular and osseous tumors, other sarcomas, nail involvement in malignant systemic disorders and metastases may occur. In most cases, they cannot be diagnosed accurately on clinical grounds. Therefore, a high degree of suspicion is necessary in all isolated or single-digit proliferations that do not respond to conservative treatment.

Pododermatitis in Captive and Free-Ranging Greater Flamingos (Phoenicopterus roseus)

Pododermatitis is frequent in captive flamingos worldwide, but little is known about the associated histopathologic lesions. Involvement of a papillomavirus or herpesvirus has been suspected. Histopathologic evaluation and viral assessment of biopsies from 19 live and 10 dead captive greater flamingos were performed. Selected samples were further examined by transmission electron microscopy and immunohistochemistry. Feet from 10 dead free-ranging greater flamingos were also evaluated. The histologic appearance of lesions of flamingos of increasing age was interpreted as the progression of pododermatitis. Mild histologic lesions were seen in a 3-week-old flamingo chick with no macroscopic lesions, and these were characterized by Micrococcus-like bacteria in the stratum corneum associated with exocytosis of heterophils. The inflammation associated with these bacteria may lead to further histologic changes: irregular columnar proliferations, papillary squirting, and dyskeratosis. In more chronic lesions, hydropic degeneration of keratinocytes, epidermal hyperplasia, and dyskeratosis were seen at the epidermis, as well as proliferation of new blood vessels and increased intercellular matrix in the dermis. Papillomavirus DNA was not identified in any of the samples, while herpesvirus DNA was seen only in a few cases; therefore, these viruses were not thought to be the cause of the lesions. Poor skin health through suboptimal husbandry may weaken the epidermal barrier and predispose the skin to invasion of Micrococcus-like bacteria. Histologic lesions were identified in very young flamingos with no macroscopic lesions; this is likely to be an early stage lesion that may progress to macroscopic lesions.

Jejunitis and brown bowel syndrome with multifocal carcinogenesis of the small bowel

This is the first report describing a case where prolonged, severe malabsorption from brown bowel syndrome progressed to multifocally spread small bowel adenocarcinoma. This case involves a female patient who was initially diagnosed with chronic jejunitis associated with primary diffuse lymphangiectasia at the age of 26 years. The course of the disease was clinically, endoscopically, and histologically followed for 21 years until her death at the age 47 due to multifocal, metastasizing adenocarcinoma of the small bowel. Multiple lipofuscin deposits (so-called brown bowel syndrome) and severe jejunitis were observed microscopically, and sections of the small bowel showed dense lymphoplasmacytic infiltration of the lamina propria as well as blocked lymphatic vessels. After several decades, multifocal nests of adenocarcinoma cells and extensive, flat, neoplastic mucosal proliferations were found only in the small bowel, along with a loss of the mismatch repair protein MLH1 as a long-term consequence of chronic jejunitis with malabsorption. No evidence was found for hereditary nonpolyposis colon carcinoma syndrome. This article demonstrates for the first time multifocal carcinogenesis in the small bowel in a malabsorption syndrome in an enteritis-dysplasia-carcinoma sequence.

Risk factors for development of internal neoplasms in koi carp (Cyprinus carpio koi)

Fish, like mammals, can be affected by neoplastic proliferations. As yet, there are only a very small number of studies reporting on the occurrence of tumours in koi carp Cyprinus carpio koi and only sporadic reports on the nature of the tumours or on risk factors associated with their development. Between 2008 and 2012, koi with abdominal swelling were examined pathologically: neoplastic lesions were diagnosed and classified histologically. We evaluated possible risk factors for the development of these internal neoplasms in koi carp in Switzerland, using an online 2-part questionnaire sent to fish keepers with koi affected by internal tumours and to fish keepers who had not previously reported any affected koi. Part 1 addressed all participants and focused on general information about koi husbandry and pond technical data; Part 2 addressed participants that had one or several case(s) of koi with internal tumour(s) between 2008 and 2012, and consisted of specific questions about affected koi. A total of 112 internal tumours were reported by the 353 koi keepers participating in the survey. Analysis of the obtained data revealed that tumour occurrence was significantly associated with the location (indoors vs. outdoors) and volume of the pond, frequency of water changes, origin of the koi, number of koi kept in a Pond and the use of certain pond disinfectant/medication products. Our results contribute to the identification of possible risk factors, which in turn could help to establish prophylactic measures in order to reduce the occurrence of internal neoplasms in koi.