Oncocytic glomus tumour: a new variant

A new variant of glomus tumour characterized by oncocytic change is reported. The light and electron microscopy and immunohistological findings are described. This is the first reported case of an oncocytoma of non-epithelial origin.     

Intravascular glomus tumour: a previously undescribed phenomenon

Summary We report the first case of an intravascular glomus tumour, which was located in the right forearm of a 40-year-old male. Microscopically the lesion originated from the wall of a vein and protruded into the lumen of the affected blood vessel. The tumour cells were characterized immunohistochemically by the presence of vimentin, actin and myosin. Within the tumour, small nerves, immunopositive for S-100 protein and neurofilaments, could be identified. Histogenetically, the tumour is thought to derive from intramural epithelioid cells of the venous part of an arteriovenous anastomosis.     

Primary neuroectodermal tumour of the testis

A 51-year-old male presented with metastasis of a small cell carcinoma of unknown origin in a right inguinal lymph node. Clinical and laboratory studies failed to locate the primary tumour. After three years, a swelling appeared in the right testis, which was removed. Histological examination revealed a proliferation of small tumour cells forming irregular masses or nests that occupied most of the testicular parenchyma. At the periphery of the testicular parenchyma a few seminiferous tubules could be observed, showing a low and incomplete seminiferous epithelium and numerous tumour cells in the lumen. Most of the tumour cells showed a euchromatic nucleus with small nucleoli and scanty cytoplasm. Among these cells, larger binucleate or trinucleate cells as well as small cells with pyknotic nuclei were also observed. Mitoses were numerous. Electron microscopy revealed some tumour cells with 80 to 100 nm vesicles containing electron-dense granules. Some cells displayed dendrite-like prolongations with numerous intermediate filaments and electron-dense vesicles. This tumour is compatible with a primary neuroectodermal tumour of the testis.     

Primary malignant 'triton' tumour of the lung

Two cases of malignant 'triton' tumour arising within lung parenchyma are described. The patients were a three-year-old child and a 53-year-old man. Both patients presented with shortness of breath and a large intrapulmonary mass on chest X-ray. Neither patient had a history of von Recklinhausen's neurofibromatosis. The lesions were treated by pneumonectomy. Grossly, both tumours presented as large, soft and gelatinous intraparenchymatous masses measuring 130 mm and 80 mm, respectively. Histologically, they were characterized by an atypical spindle cell proliferation embedded in an abundant myxoid stroma. Focal areas of rhabdomyoblastic differentiation characterized by large cells with abundant eosinophilic cytoplasm and occasional cytoplasmic cross-striations could be seen admixed with the atypical spindle cell elements. Immunohistochemical studies showed a focal positive reaction for S-100 protein in the atypical spindle cells embedded within the myxoid stroma, and a strong positive reaction for desmin and myoglobin in the rhabdomyoblastic areas. The child died three months after diagnosis with extension of the tumour into the thoracic cavity. The second patient has been lost to follow-up. Although rare, malignant 'triton' tumour should be considered in the differential diagnosis of primary spindle cell sarcomas of the lung.     

Pigmented adenomatoid odontogenic tumour

Summary A pigmented adenomatoid odontogenic tumour occurring in the mandible of a 12-year-old Japanese girl is reported. In addition to the characteristic histopathologic features, fine granules and coarse aggregates of melanin pigment were widely distributed in the spindle-shaped epithelial cells between duct-like structures, and dendritic cells containing melanin pigment were also distributed in tumour epithelium. The possible histogenesis of melanin pigment in the epithelial cells of the odontogenic lesions is discussed, although no firm conclusions could be drawn.     

Primary malignant mesenchymal tumour of the liver in an elderly female

A case of primary malignant mesenchymal tumour of the liver occurring in an 86-year-old woman is described. This very uncommon tumour has previously only been described in children and young adults, the previous oldest being 28 years of age. The tumour was large, rapidly growing though well circumscribed and extensively necrotic. Microscopically it was mostly composed of spindle cell sarcoma without differentiating features. Epithelial lined ductules were seen throughout the tumour and degenerate hepatocytes were enveloped in the tumour peripherally. Intracytoplasmic and extracellular PAS-positive, diastase-resistant bodies were present, some showing positive staining for alpha-1-antitrypsin. The tumour is compared with previous reports and its differential diagnosis and nomenclature discussed.     

肺原发性恶性外周神经鞘瘤的临床病理分析

目的 探讨肺脏原发性恶性外周神经鞘瘤(MPNST)的临床病理学特征及诊断、鉴别诊断要点。方法 对2例肺MPNST进行临床病理学分析及免疫组织化学与超微结构研究。结果 2例光镜下均显示MPNST的形态特点，免疫组织化学显示S-100蛋白、MBP、Vim、NSE肿瘤细胞呈阳性表达，电镜观察1例可见特征性Luse小体。结论 肺原发性MPNST极为罕见，临床诊断较困难。根据其光镜病理形态特征，S-100蛋白、MBP免疫组织化学检测和(或)电镜检查可确诊。结合文献，该肿瘤早期无明显临床症状，一般发现时已属晚期，预后差。病理学上应与肺脏平滑肌肉瘤、纤维肉瘤、单相型滑膜肉瘤、肉瘤样癌鉴别。     

Primary extrarenal Wilms'' tumour: identification of a putative precursor lesion

We report a case of primary extrarenal Wilms' tumour which, on histological examination, revealed a zone of hyalinized blastema adjacent to, and within the tumour capsule. The tumour showed a predominant stromal component. The presence of the hyalinized blastema adjacent to the tumour raises the possibility that some cases of extrarenal Wilms' tumour may have a precursor lesion.     

Primary lumbosacral Wilms tumour associated with occult spinal dysraphism

A 4-year-old child presenting with sudden- onset paraplegia and a sacral tumour in association with spina bifida occulta is reported. There were no stigmata of spinal dysraphism at birth. Imaging studies confirmed a sacral tumour with extradural extension up to T10 and spinal dysraphism. The histological features of the extradural and sacral components of the tumour were consistent with a Wilms tumour. The differential diagnosis included a primary sacral teratoma containing Wilms tumour elements or a primary extrarenal Wilms tumour arising in association with a spinal dysraphism. There was no clinical response to chemotherapy or radiotherapy. Received: 31 August 1999 / Accepted: 10 December 1999     

Primary renal glomus tumor with concurrent papillary renal cell carcinoma and multiple papillary adenomas in a patient with end stage renal disease: a case report and clinicopathologic analysis

Glomus tumors are mesenchymal tumors commonly seen in the extremities, and rarely seen in deep visceral organs. This is due to the lack of glomus bodies in visceral organs. Here, we describe an unusual association between glomus tumor and co-existing papillary renal cell carcinoma, multiple papillary adenomas, and end stage renal disease. We discuss our diagnostic approach and differential diagnoses, along with an extensive review of all reported benign and malignant primary glomus tumors. A 63-year-old male with a known history of a kidney transplant, end-stage renal disease, and previous nephrectomy of his right kidney due to a renal mass (papillary renal cell carcinoma) presented with a renal mass. Microscopic examination showed papillary carcinoma, multiple papillary adenomas, and a small nodule with uniform, round to oval cells. Immunohistochemical work-up revealed the small nodule to be a glomus tumor. Only 28 cases of primary renal glomus tumors have been reported in the literature. Most were discovered incidentally. None of the reported cases have occurred along with other renal tumors. This is the first case of the unusual combination of primary renal glomus tumor arising in the native kidney of a renal transplant patient with concurrent papillary renal cell carcinoma and multiple papillary adenomas (renal adenomatosis). We also explore the possible genetic basis behind this association.     

Osteoclast-like giant cell tumour of the pancreas presenting as a pseudocyst-like lesion

 A 57-year-old male patient presented with a cystic lesion in the tail of the pancreas, which was considered to be a pseudocyst. He was treated by cystojejunostomy but one year later a tumour was found to have invaded the stomach and jejunum. This was an osteoclast-like giant cell tumour containing a small area of typical ductal adenocarcinoma. Immunohistochemical staining revealed that the pleomorphic tumour cells were positive for cytokeratin, epithelial membrane antigen, vimentin and the proliferation marker MIB-1. The osteoclast-like giant cells and some small histiocytic cells stained for leukocyte common antigen and histiocytic markers and were negative for MIB-1. At autopsy, tumour rests were found in the pancreas but there were no metastases. Osteoclast-like giant cell tumours of the pancreas may present as cystic lesions and should be included in the differential diagnosis of pseudocysts. Received: 19 December 1996 / Accepted: 20 March 1997     

Primary endocardial malignant spindle-cell sarcoma in the right atrium of a dog resembling a malignant peripheral nerve sheath tumour

An unusual malignant spindle-cell sarcoma in the right atrium of a 7-year-old male hunting terrier is described. The neoplasm arose from the endocardium, protruded into the lumen of the right atrium, was covered with endothelium, and showed local invasive growth into the atrial wall. The tumour was composed of interlacing bundles of spindle cells, sometimes arranged in whorls resembling the Antoni type A pattern. The extracellular matrix showed abundant reticulin fibres. Immunohistochemistry revealed an intense labelling of tumour cells for vimentin, and a partial labelling for neuron-specific enolase, S100 protein, and Melan-A. The morphology of the tumour indicated a primary malignant peripheral nerve sheath tumour, resembling a neoplasm described in rats.     

Primary signet‐ring stromal tumour of the testis: case report with literature review

Primary signet‐ring stromal tumour of the testis (PSRSTT) is a very rare type of primary testicular tumour, which is not actually mentioned in the current WHO categorization of tumours of the male genital organs. In this case we report about histologically and immunohistochemically features of this rare tumour. In the present case, PSRTT was found in the orchiectomy preparation of a 69‐year‐old man with painless swelling of his left testicle. The tumour was well circumscribed and separated from the normal testicular tissue by a fibrous capsule. The tumour cells showed a signet‐ring pattern and were separated by thin collagen bundles. No mitotic activity and necrosis were found inside the tumour. Immunohistochemically, the tumour was positive for vimentin, neuron‐specific enolase (NSE), S‐100 protein, β‐catenin and cyclin D1. No expression of cytokeratin, actin, SALL4, OCT3/4, and especially, inhibin and calretinin were detected. In conclusion, the presence of signet‐ring cell formation can be found in different tumours of the testis. PSRSTT is a rare tumour that needs to be considered, in particular, to distinct them from other tumours with signet‐ring cell pattern.     

Primary tumour genetic alterations and intra-tumoral heterogeneity are maintained in xenografts of human colon cancers showing chromosome instability

Evaluation of the role of clonal heterogeneity in colon tumour sensitivity/resistance to drugs and/or in conferring metastatic potential requires an adequate experimental model in which the tumour cells maintain the initial genetic alterations and intra-tumoral heterogeneity through maintenance of the genetic clones present in the initial tumour. Therefore, we xenografted subcutaneously into nude mice seven human colonic tumours (from stages B1 to D) that showed chromosome instability and transplanted them sequentially for up to 14 passages. Maintenance after xenografting of the genetic alterations present in the initial tumours was scored by allelotype studies targeting 45 loci localized on 18 chromosomes. We show that xenografting does not alter the genetic or the histological profiles of the tumours even after 14 passages. Screening of the entire genome of one tumour by comparative genome hybridization also showed overall stability of the alterations between the initial and the xenografted tumour. In addition, intra-tumoral heterogeneity was maintained over time, suggesting that no clonal selection occurred in the nude mice. The observation that some loci showed partial allelic imbalance in the initial tumour but loss of heterozygosity after the first passage in nude mice when all the normal cells were lost may allow identification of interesting genetic defects that could be involved in tumour expansion. Thus, sequential xenografts of colon tumours will provide a powerful model for further study of tumour clonality and for the identification of genetic profiles responsible for differential resistance to therapeutic treatments. Our data also suggest that tumour expansion can result from alterations in several distinct genetic pathways.