[Tumor-suspected focal lesion on the renal hilus]. / Tumorverdächtiger Herdbefund am Nierenhilus.

Mucosal structures of a non-neoplastic organ can result in a pitfall diagnosis of adenocarcinoma in the case of a wrong correlation with other organs, in this case caused by an adherent gallbladder to the hilar structures of the right kidney. Clinical and radiological data are absolutely crucial for a correct classification.

[A suspected carcinoma finding in the uterus]. / Karzinomverdächtiger Herdbefund im Uterus.

Epithelioid tumor cells of a uterine perivascular epithelioid cell tumor (PEComa) may mimic carcinoma cells in an endometrial sampling (pitfall). Immunohistochemistry (HMB45 positive, keratin negative) helps in the differential diagnosis.

[Intravascular papillary endothelial hyperplasia (IPEH) : Masson's pseudoangiosarcoma on the forefoot]. / Intravaskuläre papilläre endotheliale Hyperplasie (IPEH) : Masson-Pseudoangiosarkom am Vorfuß.

Intravascular papillary endothelial hyperplasia (IPEH)/Masson's pseudoangiosarcoma is a rare (orphan) disease of the forefoot that has not yet been described in Europe. The pathoanatomic examination of a young patient with a vague interdigital space-consuming lesion revealed a intravascular papillary endothelial hyperplasia/Masson's pseudoangiosarcoma. The intravascular papillary endothelial hyperplasia can be mainly detected in the upper limbs as well as cervically. Heretofore, the intravascular papillary endothelial hyperplasia has only been described in Japan and the USA. For Europe, our case report is the first description of the clinical course of IPEH.

Malignant Glomus Tumour (Glomangiosarcoma) with Additional Neuroendocrine Differentiation in a Horse.

A 13-year-old Icelandic crossbred horse was presented with headshaking and progressive impairment of chewing. A slowly growing mass was identified in the anterior maxilla. This was associated with lysis of the alveolar bone and the roots of the incisors and there were nodular proliferations affecting the nasal septum and conchae. There was no response to chemotherapy and so the horse was humanely destroyed. Based on morphological, immunohistochemical and ultrastructural findings the mass was classified as a malignant glomus tumour with multifocal vascular spaces and additional neuroendocrine differentiation. An oronasal glomus tumour with neuroendocrine differentiation has not been described previously in an animal.

[Gastric ulcer suspected of being a carcinoma]. / Karzinomverdächtiges Magenulkus.

Following hepatic penetration by a gastric ulcer a pitfall diagnosis of gastric adenocarcinoma can result from a biopsy of the ulcer base. In cases of suspicious "hepatoid" epithelial cells in a gastric biopsy, the possibility of regular liver tissue from a gastric ulcer penetrating the liver should be kept in mind and verified, e.g. by immunohistochemistry.

[Tumor of the peroneal compartment]. / Tumor der Peronäusloge.

Degenerative nuclear atypia in mesenchymal neoplasia, especially in benign nerve sheath tumors, may become a pitfall leading to a wrong diagnosis of a sarcoma. Using a case of degenerative (ancient) schwannoma as an example, the characteristic findings of degenerative atypia are presented and discussed.

[Atypical lipomatous tumors of the stomach. Clinical, morphological and molecular findings]. / Atypische lipomatöse Tumoren des Magens. Klinische, morphologische und molekularbiologische Befunde.

Two cases of primary gastric atypical lipomatous tumors (ALT) are presented. In case No.1, a 7x4x3 cm submucosal ALT (lipoma-like subtype) of the antrum/pyloric region in a 60-year-old woman was completely resected. Using interphase dual-color-FISH, MDM2- and CDK4 amplifications could be detected in distinguished amplicons. The patient was continuously free of disease after 56 months. In case No. 2, a 3.5 cm (in diameter) submucosal ALT (lipoma-like subtype) of the gastric body in a 56-year-old woman was completely resected. FISH revealed MDM2 amplification while the CDK4 gene remained in diploid copies. This patient was continuously free of disease after 36 months. The morphologic and molecular biological findings of this rare primary gastric mesenchymal tumor are discussed in comparison with the corresponding soft tissue lesions.

[Myositis ossificans traumatica of the palm]. / Myositis ossificans traumatica der Hohlhand.

We present a 27-year-old female patient who developed a post-traumatic myositis ossificans with pain and restricted function after trigger finger release of the middle finger. After tumour resection an early recurrence made a re-resection necessary, followed by radiotherapy. Three years postoperatively the patient is free of complaints.

[Gardner fibroma: case report and discussion of a new soft tissue tumor entity]. / Gardner-Fibrom: Eine neue mesenchymale Tumorentität als Indikatorläsion.

Gardner fibroma represents a rare and recently described soft tissue tumor entity in children and young adults. It consists of haphazardly arranged coarse and hyalinized collagen fibers combined with loosely arranged bland spindle and fibroblastic cells. The case of a 13-year-old male patient with Gardner fibroma and osteoma and multicentric desmoid type fibromatosis in his mother is presented with detection of a (heterozygotic) germline mutation of the APC gene leading to a de novo stop codon (deletion of base pairs 5033-5036). FISH analysis revealed a structural loss of heterozygosity (LOH) in the APC gene on chromosomal locus 5q21 in one out of five analysed desmoids of the mother, no LOH of APC gene in the Gardner fibroma. Gardner fibroma in children and young adults may serve as an indicator lesion for familial adenomatous polyposis (FAP), Gardner syndrome, a familial desmoid type fibromatosis without other manifestations of APC or a new APC gene mutation. For the clinician, this diagnosis should be commented upon accordingly by the surgical pathologist. As the result of a detected APC gene mutation, continuous follow-up for the development of colorectal tumors and desmoid type fibromatosis as well as a familial screening for FAP is recommended.

[Lipoma and atypical lipomatous tumor within the same neoplasia: Evidence for a continuous transition]. / Lipom und atypischer lipomatöser Tumor innerhalb einer Neoplasie: Hinweis für einen kontinuierlichen Ubergang.

The case of a lipomatous tumor with a predominant lipoma component and transition to an atypical lipomatous tumor is presented. A deep-seated soft tissue tumor of the right thigh with a maximum size of 14 cm was resected in a 70-year-old female patient. Corresponding to a comparable macroscopic aspect, the lesion revealed the histological features of an ordinary lipoma without atypia in about 80% of the specimen. In the remaining portion (approximately 20%) histopathology showed an atypical lipomatous tumor (ALT, lipoma-like subtype). Immunohistochemistry for MDM 2 and CDK4 revealed no immunoreactivity in the lipoma component, but within the ALT component. Interphase dual-color fluorescence in situ hybridization showed no amplification of the MDM 2 gene and rarely CDK4 gene amplification within the lipoma component, but high level amplification of MDM 2/CDK4 gene in the ALT area, further supporting the morphologically based diagnosis of a lipomatous tumor including areas of a true lipoma and ALT. This case underlines the concept of a continuous stepwise development of lipomatous soft tissue tumors from benign to malignant counterparts as a biological continuum.

[Cystic desmoplastic small round cell tumor: tumor development from cystic-"mesothelioblastic" areas?]. / Zystischer desmoplastischer klein- und rundzelliger Tumor: Tumorentwicklung aus zystisch-"mesothelioblastischen" Arealen?

A 7-cm cystic lesion in the upper left abdomen and additional smaller solid tumor nodules were diagnosed incidentally in a 15-year-old boy without tumor symptoms. The main tumorous cystic lesion showed a flattened single-cell tumor cell component in gradual transition to stratified, papillary and truly "invasive" typical desmoplastic areas of a desmoplastic small round-cell tumor (DSRCT). The Ki-67-proliferation index gradually increased within three histologic tumor patterns up to about 70% in the typical desmoplastic (infiltrating) component. Using microdissection techniques, EWS-WT1-gene fusion transcripts were detected in the cystic (single-cell-layered), the papillary and the solid tumor proliferations (exon 7 of EWS on chromosome 22 with exon 8 of WT1 on chromosome 11). The presented case illustrates a predominant cystic growth pattern of DSRCT, in which a stepwise development in the pathogenesis of DSRCT from cystic (-"mesothelioblastic") towards a more papillary proliferation and finally typical "infiltrative" desmoplastic tumor pattern might be discussed. The cystic pattern could represent an initial stage in the development of the neoplasia. The presence of specific EWS-WT1-gene fusion transcripts in all tumor growth patterns in this respect would indicate an early event in t(11;22)(p13;q12) translocation in the pathogenesis of DSRCT.

[Identification of genes over-expressed in myxoid/round cell liposarcoma. DNA microarray analysis and immunohistochemical correlation]. / Identifikation überexprimierter Gene in myxoid-rundzelligen Liposarkomen. DNA-Mikroarray-Analyse und immunhistochemische Korrelation.

Myxoid/round cell liposarcoma are characterized by typical chromosomal translocations. This genetic alteration might result in specific gene-expression profiles in this tumor entity. To identify over-expressed genes in myxoid/round cell liposarcoma DNA microarray analysis was performed on four tumors and four samples of adult fat tissue. Genes ret, cdk4, cyclin D2 and c-myc showed over-expression by means of microarray analysis and Northern blotting. Immunohistochemistry demonstrated cytoplasmic localization of associated proteins in 36 different tumors. The localization of ret was seen in endothelial cells of plexiform vasculature in addition to its accumulation in tumor cells (25% of cases). The results show an over-expression of cdk4, cyclin D2, c-myc and ret on both the transcriptional and protein level in myxoid/round cell liposarcoma. For cyclin D2 and ret this finding has not been reported in this tumor type. The increase of ret on transcriptional level might be explained by its expression in endothelium in intratumoral plexiform blood vessels. For the molecular pathogenesis of myxoid/round cell liposarcoma our findings imply the involvement of these four genes in the deregulation of the cell cycle, especially as cdk4 and cyclin D2 are target genes of c-myc.

Lymph node metastases in soft tissue sarcomas: a single center analysis of 1,597 patients.

PURPOSE: The aim of this study was to examine the clinical course of patients with the rare finding of regional lymph node metastasis (RLNM) from soft tissue sarcoma. MATERIALS AND METHODS: Data from 28 out of 1,597 consecutive soft tissue sarcoma patients with RLNM were from the patients' charts and interviewing patients and general practitioners. Survival, including possible influencing factors, was statistically calculated. RESULTS: RLNM was seen in 21.4% for epithelioid sarcoma and 17.6% for clear cell sarcoma. All other entities presented RLNM rates below 10%. At follow-up after an average of 9.6 years, only three patients were alive with no evidence of disease. Survival was independent from surgical resection status of the primary tumor and the RLNM as well as from adjuvant radiation and chemotherapy. Tumor entity as well as the length of the time period from primary to RLNM affect survival. CONCLUSIONS: Surgical treatment as well as radiation and chemotherapy may improve survival in selected cases but probably have their value much more in terms of local disease control and improvement life quality of patients who probably already suffer from an aggressive systemic disease at time of nodal involvement.

Aneurysmal bone cyst of the cervical spine (2008:7b).

Aneurysmal bone cysts (ABC) are rare, benign, but locally destructive bone tumors. They occur in the spine in 14% of cases, but only 2% are found in the cervical spine. This case report presents a 16-year-old female with an expansive aneurysmatic bone cyst with extensive bone destruction and instability in the cervical segments C1 and C2. In CT and MRI, there was a soft-tissue tumor mass with multiple cysts and fluid-fluid levels within these cysts, as well as contrast enhancement of the cyst wall and the tissue among the cysts. The typical macroscopic and histological findings were present. The tumor was resected en bloc, after which the patient underwent adjuvant radiation therapy. The patient made a complete recovery.