Pleomorphic hyalinizing angiectatic tumor revisited: all tumors manifest typical morphologic features of myxoinflammatory fibroblastic sarcoma, further suggesting 2 morphologic variants of a single entity

Superficial CD34+ fibroblastic tumor with focal atypical presentation: A case report

Superficial CD34+ fibroblastic tumors (SCPFTs) are rare mesenchymal tumors with distinct morphological features. Although several cases of SCPFT have been reported, a comprehensive understanding of its clinical and biological features necessitates the inclusion of additional cases. The current study presents a case of SCPFT, where morphological observations, immunohistochemical staining and fluorescence in situ hybridization (FISH) were performed. Immunohistochemistry revealed diffuse CD34 expression and integrase interactor 1 expression, whilst FISH indicated rearrangement of the PR/SET domain 10 gene. Microscopic assessment demonstrated typical SCPFT pathology, with a focal nodular region showing a high Ki-67 index, suggesting heterogeneity and the potential for local recurrence. The present study also briefly reviews the differential diagnosis of tumors with morphological similarities. It was found that the precise diagnosis of SCPFT relies on the distinctive pathological features, the use of immunohistochemical markers, including CD34 staining, and the differentiation from similar histological lesions.

Myxoinflammatory Fibroblastic Sarcoma

MIFS is a low-grade fibroblastic sarcoma that predilects to superficial distal extremity soft tissue. It is composed of plump spindled and epithelioid cells, inflammatory infiltrates, and mucin deposits in a fibrosclerotic stroma. Large epithelioid cells harboring bizarre nuclei and virocyte-like macronucleoli and pleomorphic pseudolipoblasts are characteristic. While conventional MIFS has locally recurrent potential but minimal metastatic risk, tumors with high-grade histologic features have a greater risk for recurrence and metastasis. Wide local excision is the recommended treatment.

Recent Advances in the Diagnosis, Pathogenesis, and Management of Myxoinflammatory Fibroblastic Sarcoma

Myxoinflammatory fibroblastic sarcoma (MIFS) is an infiltrative, locally aggressive fibroblastic neoplasm of intermediate malignancy that typically arises in the distal extremities of middle-aged adults. It can histologically be confused with a number of benign and malignant conditions. Recently, high-grade examples of MIFS have been described. Immunohistochemistry plays a very limited role in the diagnosis of MIFS. Several genetic alterations have been identified in MIFS, including a t(1;10)(p22;q24) translocation with TGFBR3 and/or OGA rearrangements, BRAF rearrangement, and VGLL3 amplification. Although it appears that VGLL3 amplification is the most consistent alteration, the molecular pathogenesis of MIFS remains poorly understood. A wide resection is considered the standard treatment for MIFS. Radiotherapy may be a viable option in cases with inadequate surgical margins or cases where surgery is likely to cause significant functional impairment. The systemic treatment options for advanced or metastatic disease are very limited. This review provides an updated overview of the clinicoradiological features, pathogenesis, histopathology, and treatment of MIFS.

Pleomorphic hyalinizing angiectatic tumor: FNA analysis of a rare entity and review of the literature

INTRODUCTION

The fine-needle aspiration (FNA) cytopathology of pleomorphic hyalinizing angiectatic tumor (PHAT) is the subject of a very limited number of reports. We undertook a review of our FNA experience with this neoplasm.

MATERIALS AND METHODS

A search was made of our files for PHAT FNA cases with histopathologic confirmation. FNA biopsy smears and cell blocks were performed and examined using standard techniques.

RESULTS

Two primary cases of histologically proven PHAT [both male, ages 56 and 60 years] met study inclusion. FNA sites included buttock and foot. A misdiagnosis of sarcoma was made in each case. Ancillary immunohistochemical testing performed in 1 case suggested angiosarcoma. Cytologic smears showed only modest cellularity with a dual population of bland spindle cells and isolated large pleomorphic cells, many harboring nuclear pseudoinclusions. Smear background was clean, and mitoses absent.

CONCLUSIONS

The imitative cytopathology of PHAT with a pleomorphic sarcoma remains a pitfall in FNA specimens. Awareness of this entity and its lack of hypercellularity, necrosis, and cohesive groups of atypical cells in smears should assist the cytopathologist in avoiding a misdiagnosis of malignancy.

Myxoinflammatory fibroblastic sarcoma: an immunohistochemical and molecular genetic study of 73 cases

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare, low-grade soft tissue neoplasm preferentially arising in the extremities of young to middle-aged adults characterized histologically by a variegated appearance and absence of a distinctive immunophenotype. Herein we have evaluated a series of 73 cases of MIFS to define potential features and markers that may facilitate diagnosis. An immunohistochemical study with a large panel of antibodies showed strong positivity of the tumor cells for bcl-1 (94.5%), FXIIIa (89%), CD10 (80%), and D2-40 (56%). FISH and array comparative genomic hybridization (aCGH) were performed in a large subset of cases to investigate the utility for detecting the TGFBR3 and OGA t(1;10) rearrangement and BRAF abnormalities. Using a combination of FISH and/or aCGH, t(1;10) was detected in only 3 of 54 cases (5.5%). The aCGH study also demonstrated amplification of VGLL3 on chromosome 3 that was detected in 8 of 20 cases (40%). BRAF alterations were observed by FISH in 4 of 70 cases (5.7%) and correlated with gain of chromosome 3p12 (VGLL3). A novel fusion transcript involving exon 6 of ZNF335 and exon 10 of BRAF was identified in one case. Demonstration of amplification of VGLL3 on chromosome 3 in combination with expression of bcl-1 and FXIIIa may help support the diagnosis, however, due to their low specificity these markers are not sufficient for a definitive diagnosis in the absence of the appropriate clinical-pathological context. Until a more robust genetic or immunohistochemical signature is identified, the diagnosis of MIFS rests on its characteristic clinicopathological features.

The t(1;10)(p22;q24) TGFBR3/MGEA5 Translocation in Pleomorphic Hyalinizing Angiectatic Tumor, Myxoinflammatory Fibroblastic Sarcoma, and Hemosiderotic Fibrolipomatous Tumor

CONTEXT.—

Pleomorphic hyalinizing angiectatic tumor (PHAT) of soft parts, hemosiderotic fibrolipomatous tumor (HFLT), and myxoinflammatory fibroblastic sarcoma (MIFS) are 3 distinct entities of low-grade spindle cell mesenchymal neoplasm. These tumors have similar clinical presentations and partially overlapping but distinctive pathologic features. A recurrent translocation, t(1;10)(p22;q24), has been detected in a subset of PHAT, HFLT, MIFS, and HFLT/MIFS hybrid cases. Translocation t(1;10)(p22;q24) involves transforming growth factor β-receptor 3 ( TGFBR3) and meningioma-expressed antigen 5 ( MGEA5) genes on chromosomes 1p22 and 10q24, respectively. However, the percentage of translocation in PHAT, HFLT, and MIFS varies significantly among different studies. The relationship among these tumors has been a controversial topic among experts.

OBJECTIVE.—

To discuss the diagnostic and functional significance of translocation t(1;10)(p22;q24) TGFBR3/MGEA5 rearrangement in HFLT, PHAT, and MIFS.

DATA SOURCES.—

PubMed was used for this study.

CONCLUSIONS.—

Diagnosis of HFLT, PHAT, and MIFS is challenging because of a lack of unique morphologic, immunophenotypic, molecular, and cytogenetic markers. The recurrent t(1;10)(p22;q24) translocation and/or TGFBR3/MGEA5 rearrangement was reported in 55 patients, with a relatively even distribution among HFLT, PHAT, and MIFS (17 HFLT, 15 MIFS, 13 MIFS/HFLT, and 10 PHAT). This indicates that current morphology-based diagnostic criteria do not identify reliably the subset of soft tissue tumor with t(1;10) translocation. Genetic heterogeneity of these tumors is supported by the recent detection of a mutually exclusive, second recurrent genetic change, t(7;17) TOM1L2-BRAF translocation or BRAF amplification, in a subset of MIFS.

Synovial Sarcoma Mimicking Pleomorphic Hyalinizing Angiectatic Tumor of Soft Parts: A Case Report

Synovial sarcoma is a high-grade sarcoma commonly affecting young adults. The sites of involvement include soft tissue near joints, lung, pleura, mediastinum, larynx, kidney, and buttocks. Histologic types include monophasic, biphasic, and undifferentiated. We report a unique case of synovial sarcoma with low-grade histologic features mimicking pleomorphic hyalinizing angiectatic tumor (PHAT) with indolent behavior for a period of 10 years. The tumor showed angiectatic blood vessels with fibrinous cuffing, hypocellular and hypercellular spindle cell areas with rare mitoses, and focal atypia in a myxoid background. TLE1 was positive with SYT gene translocation detected on fluorescent in situ hybridization. Cases of myxoinflammatory fibroblastic sarcoma and myxofibrosarcoma have been reported as exhibiting histologic features of PHAT. However, to the best of our knowledge, cases of synovial sarcoma mimicking PHAT have not been reported.

Sarcomatous transformation of a hemosiderotic fibrohistiocytic lipomatous tumor: a case report

Hemosiderotic fibrohistiocytic lipomatous tumors are rare neoplasms that were first described in 2000. Initially considered a benign lipotamous lesion of the soft tissues, nowadays they are considered to be a locally aggressive tumor. They occur mainly in the foot and ankle of women in their fifth and sixth decades, although they may be found in any place in the lower limbs and, more rarely, in other parts of the body. Histologically, hemosiderotic fibrohistiocytic lipomatous tumors consist of a mixture of mature adipose tissue, fusiform cell fascicles, macrophages that often contain cytoplasmic hemosiderin, mononuclear inflammatory infiltrate, and stroma that may be focally myxoid. Local recurrence is observed in nearly one-third of all cases. There is no consensus in the literature whether this tumor is a part of a spectrum that comprises pleomorphic hyalinizing angiectatic tumors and myxoinflammatory fibroblastic malignant tumors, or if it is an independent entity.

The authors report a case of a neoplasia after a diagnosis of a hemosiderotic fibrohistiocytic lipomatous tumor in a 38-year-old woman, with two recurrences and later sarcomatous transformation. An immunohistochemical study indicated myofibroblastic differentiation of a malignant neoplasm. To the best of the authors’ knowledge, there are only few reported cases of malignant transformation in hemosiderotic fibrohistiocytic lipomatous tumors.

Superficial CD34-positive fibroblastic tumour: a clinicopathological and immunohistochemical study of an additional series

AIMS

To describe an additional series of superficial CD34-positive fibroblastic tumour, a newly described neoplasm, in order to enhance the recognition of an emerging novel entity.

METHODS AND RESULTS

The clinicopathological features and immunophenotypes of 11 cases of superficial CD34-positive fibroblastic tumour were studied. There were eight males and three females, with a median age of 36 years. Tumours occurred in the thigh (n = 4), buttock (n = 3), shoulder (n = 2), upper arm (n = 1), and waist (n = 1). Histologically, all tumours were characterized by relative circumscription, pleomorphic spindled to polygonal cells with variably enlarged bizarre-appearing cells, intranuclear cytoplasmic pseudoinclusions, and extremely low mitotic activity. Immunohistochemically, neoplastic cells showed diffuse and strong expression of CD34 and focal staining of cytokeratin. Follow-up thus far has revealed an indolent clinical behaviour.

CONCLUSIONS

Superficial CD34-positive fibroblastic tumour represents a new member of the family of cutaneous CD34-positive spindle-cell tumours. Familiarity with its clinicopathological characteristics is helpful in avoiding confusion with a variety of cutaneous mesenchymal tumours with overlapping features.

Clinical implications of a rare renal entity: Pleomorphic Hyalinizing Angiectatic Tumor (PHAT)

Pleomorphic Hyalinizing Angiectatic Tumor (PHAT) is a rare benign lesion characterized by slow growth, infiltrative behavior and high rate of local recurrences. Only one case has been described in retroperitoneum, at renal hilum, but not involving pelvis or parenchyma. Here we present the first case of PHAT arising in the renal parenchyma. A nodular lesion in right kidney lower pole was diagnosed to a 61 year old woman. The patient underwent right nephrectomy. Microscopically, the lesion showed solid and pseudo-cystic components with hemorrhagic areas characterized by aggregates of ectatic blood vessels. Pleomorphic cells were characterized by large eosinophilic cytoplasm with irregular and hyperchromatic nuclei. Immunohistochemistry was performed and the lesion was classified as a Pleomorphic Hyalinizing Angiectatic Tumor (PHAT). Due to the clinical behavior of this tumor, in spite of its benign nature, review of the surgical margins and close follow up after partial nephrectomy are mandatory.