Die neue WHO-Klassifikation und aktuelle Ergebnisse in der Weichteiltumorpathologie

Soft Tissue Perivascular Epithelioid Cell Tumour: An Unusual Finding

Perivascular epithelioid cell tumour (PEComa) is a rare mesenchymal tumour made up of clear perivascular cells with epithelioid characteristics, which co-expresses muscle and melanocytic markers with a component of spindle cells, like sarcoma and variety of other tissues. This time, we present the case of a young patient with a tumour in the dorsal region of progressive growth, compatible with PEComa of soft tissue after histopathological and immunohistochemical analysis.

Genome-wide methylation profiling and copy number analysis in atypical fibroxanthomas and pleomorphic dermal sarcomas indicate a similar molecular phenotype

Background

Atypical fibroxanthomas (AFX) and pleomorphic dermal sarcomas (PDS) are lesions of the skin with overlapping histologic features and unspecific molecular traits. PDS behaves aggressive compared to AFX. Thus, a precise delineation, although challenging in some instances, is relevant.

Methods

We examined the value of DNA-methylation profiling and copy number analysis for separating these tumors. DNA-methylation data were generated from 17 AFX and 15 PDS using the Illumina EPIC array. These were compared with DNA-methylation data generated from 196 tumors encompassing potential histologic mimics like cutaneous squamous carcinomas (cSCC; n = 19), basal cell carcinomas (n = 10), melanoma metastases originating from the skin (n = 11), leiomyosarcomas (n = 11), angiosarcomas of the skin and soft tissue (n = 11), malignant peripheral nerve sheath tumors (n = 19), dermatofibrosarcomas protuberans (n = 13), extraskeletal myxoid chondrosarcomas (n = 9), myxoid liposarcomas (n = 14), schwannomas (n = 10), neurofibromas (n = 21), alveolar (n = 19) and embryonal (n = 17) rhabdomyosarcomas as well as undifferentiated pleomorphic sarcomas (n = 12).

Results

DNA-methylation profiling did not separate AFX from PDS. The DNA-methylation profiles of the other cases, however, were distinct from AFX/PDS. They reliably assigned to subtype-specific DNA-methylation clusters, although overlap occurred between some AFX/PDS and cSCC. Copy number profiling revealed alterations in a similar frequency and distribution between AFX and PDS. They involved losses of 9p (22/32) and 13q (25/32). Gains frequently involved 8q (8/32). Notably, a homozygous deletion of CDKN2A was more frequent in PDS (6/15) than in AFX (2/17), whereas amplifications were non-recurrent and overall rare (5/32).

Conclusions

Our findings support the concept that AFX and PDS belong to a common tumor spectrum. We could demonstrate the diagnostic value of DNA-methylation profiling to delineating AFX/PDS from potential mimics. However, the assessment of certain histologic features remains crucial for separating PDS from AFX.

[Benign mesenchymal tumors of the abdomen]

BACKGROUND

Benign mesenchymal tumors of the abdomen are-except for hemangiomas-rare neoplasms that are associated with potentially life-threatening complications. Thus, awareness of the most important entities and knowledge of their imaging characteristics is fundamental for the radiologist.

OBJECTIVES

An overview of the most frequent benign abdominal soft tissue tumors and their common imaging features is given. Furthermore, other facts concerning the individual entities that are relevant to radiologic practice are outlined.

MATERIALS AND METHODS

A literature search and evaluation of the institutional image database were performed.

RESULTS

Hemangiomas, desmoid tumors, lipomas and lipoma variants are presented. Typical characteristics and radiological signs (e. g., iris diaphragm sign, band sign, India ink artifact) are elucidated and illustrated by image examples.

CONCLUSION

Despite the lack of distinctive imaging features, there are a few radiological characteristics suggestive for each of the entities that in many cases allow for correct diagnosis. In cases of doubt, biopsy or surgery is necessary to distinguish them from malignancies.

[Borderline and malignant mesenchymal tumors of the abdomen]

BACKGROUND

Soft tissue sarcomas are most common mesenchymal malignancies in the abdomen. Their radiologic features are often unspecific and establishing a differential diagnosis to other pathologies can be difficult.

OBJECTIVES

This review presents a selection of the most common mesenchymal abdominal tumors and their imaging characteristics, as well as the associated differential diagnoses. Knowledge of fundamental pathologic, anatomic and radiologic features of these malignancies is crucial for the differential diagnosis and key in clinical decision making and subsequent selection of an appropriate therapeutic regimen.

A painful, vascularised tumour of the calf

The case of a 39-year old female patient, presenting a painful, well-vascularized tumour located in the subcutaneous tissue of the right calf, is reported. Due to the painfulness and tumour size progression an excision with primary wound closure (by buried sutures) was performed. The tumour showed histological features characteristic for an angioleiomyoma. Particularly middle-aged women are affected by an angioleiomyoma which represents a benign, mesenchymal tumour mostly located on the lower extremities. Differential diagnosis in painful tumours of the skin should include this entity. Because of the painfulness of the tumour primary excision is mostly recommended. In the majority of cases the diagnosis is made histologically.

Clinical implications of PTEN and VEGF expression status, as well as microvessel density in esophageal squamous cell carcinoma

There are limitations to the use of single biomarker levels, for example phosphate and tensin homology (PTEN) or vascular endothelial growth factor (VEGF), in the diagnosis of esophageal squamous cell carcinoma (ESCC). The present study therefore aimed to evaluate the clinical implications of combined detection of multiple biomarkers. The associations between PTEN and VEGF expression status, microvessel density (MVD), and the pathological characteristics of 50 patients with ESCC were determined using χ², analysis of variance, and t-tests. The results indicated that the PTEN-positive rate was negatively correlated with ESCC histological grade (P<0.01), depth of ESCC invasion (P<0.01) and lymph node metastasis status. Furthermore, the VEGF-positive rate was correlated with lymph node metastasis status, while MVD was correlated with the depth of ESCC invasion (P<0.01) and lymph node metastasis status (P<0.05). The PTEN-positive rate was negatively correlated with the VEGF-positive rate. A higher MVD was identified in ESCC samples than that of the normal esophageal mucosa, particularly in VEGF-positive ESCC specimens compared with those of VEGF-negative specimens, and PTEN-negative ESCC specimens compared with that of the PTEN-positive ESCC specimens. These results suggested that combined detection of PTEN and VEGF levels, as well as evaluation of MVD in patients with ESCC may provide essential information for improvements in the diagnosis and prognosis of ESCC.