Pleomorphic Hyalinizing Angiectatic Tumor Research Articles

Pleomorphic Hyalinizing Angiectatic Tumor (PHAT): Review of the Literature with Case Presentation.

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a very rare entity of soft tissue considered a “neoplasm of uncertain behaviour of connective or other soft tissue” by the World Health Organization (2020). It develops in subcutaneous tissue of the lower extremities, more frequently in the region of the ankle and foot, and rarely as a deep-seated soft tissue mass in locations such as the perineum, buttock, arms, head and neck, and viscera. Although inconsistent cytogenetic data have been reported on PHAT so far, there are potential morphological and genetic overlaps with hemosiderotic fibrolipomatous tumor (HFLT) and myxoinflammatory fibroblastic sarcoma (MIFS). Here we report a case of PHAT at the level of the upper third of the right thigh in a 48-year-old patient and we also focus on the differential diagnoses of these entities and conduct a literature review of reported cases.

A Subcutaneous Pleomorphic Hyalinizing Angiectatic Tumor of Soft Parts of the Right Ankle: A Case Report

Abstract- Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare, slow-growing mass, which is locally aggressive and classified as tumors of borderline malignancy. In this study, we report a case of subcutaneous ankle mass in 43-year-old female since 2 years ago with a pathological diagnosis of PHAT, characterized by clusters of ectatic, fibrin-lined, and thin-walled vessels which are surrounded by a spindled or pleomorphic neoplastic stroma.

A pelvic pleomorphic hyalinizing angiectatic tumor: a rare case report

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a particular rare entity corresponding to soft tissue neoplasm with low malignant potential. The exact etiopathology responsible for the tumor occurrence is not exactly identified. Knowledge of this condition is necessary to avoid misdiagnosis of the lesion and subsequently, to adopt the proper management. Here we report a case of PHAT originating from soft tissue in the pelvic retroperitoneum. According to the litterature, few articles deal with such pathology and such location. This work illustrates features of the tumor, its characteristics, and the adequate management with the histopathological findings.

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

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

TGFBR3 and MGEA5 rearrangements are much more common in “hybrid” hemosiderotic fibrolipomatous tumor-myxoinflammatory fibroblastic sarcomas than in classical myxoinflammatory fibroblastic sarcomas: a morphological and fluorescence in situ hybridization study

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare low-grade sarcoma that most often involves the distal extremities of adults. Some MIFSs have been reported to show TGFBR3 and MGEA5 rearrangements. TGFBR3 and MGEA5 rearrangements have also been reported in hemosiderotic fibrolipomatous tumor (HFLT), in pleomorphic hyalinizing angiectatic tumor (PHAT), and in rare tumors allegedly showing features of both HFLT and MIFS (hybrid HFLT-MIFS). These findings have led to speculation that HFLT, MIFS, PHAT, and hybrid HFLT-MIFS are closely related; however, areas resembling HFLTs are only very rarely encountered in previous series of MIFSs. We studied classic examples of these tumors with the goal of clarifying the relationship between MIFS and HFLT-MIFS. Cases of MIFS (n=31), hybrid HFLT-MIFS (n=8), PHAT (n=2), HFLT (n=1), and undifferentiated pleomorphic sarcoma (n=4) were retrieved from our archives, and the diagnoses were verified by 5 soft tissue pathologists. Using previously validated break-apart fluorescence in situ hybridization probes, we analyzed for TGFBR3 and MGEA5 rearrangements. Only 2 of 31 MIFSs harbored MGEA5 rearrangements; all lacked TGFBR3 rearrangements. Six of 8 hybrid HFLT-MIFSs harbored rearrangements of TGFBR3 and/or MGEA5. Both PHATs were positive for rearrangements of TGFBR3 and/or MGEA5. The HFLT was positive for rearrangements of both TGFBR3 and MGEA5. All undifferentiated pleomorphic sarcomas with focal myxoid change were negative. We conclude that (1) TGFBR3 and/or MGEA5 rearrangements are much more common in hybrid HFLT-MIFSs than in classic MIFSs, (2) HFLTs and MIFSs may be unrelated lesions, and (3) hybrid HFLT-MIFSs most likely represent HFLTs with sarcomatous progression, rather than tumors strictly related to classic MIFSs.

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

We describe 9 cases of pleomorphic hyalinizing angiectatic tumor (PHAT). Recently described TGFBR3 and MGEA5 gene rearrangements in these tumors have confirmed the long-hypothesized link between PHAT and another soft tissue entity, the myxoinflammatory fibroblastic sarcoma (MIFS). Myxoinflammatory fibroblastic sarcoma and PHAT share the same translocation and in addition have a very similar clinical presentation. However, to our best knowledge, no study has ever addressed the striking morphologic similarities between MIFS and PHAT. Our findings based on histological criteria suggest that most, if not all, tumors diagnosed as PHAT might, in fact, represent examples of MIFS that, in addition to a conventional MIFS morphology, manifest aberrant angiectatic hyalinized vessels.

Large pleomorphic hyalinizing angiectatic tumor of the forearm: A multidisciplinary perspective

Large pleomorphic hyalinizing angiectatic tumor of the forearm: A multidisciplinary perspective

High-grade myxoinflammatory fibroblastic sarcoma: a report of 23 cases

We describe 23 cases of high-grade myxoinflammatory fibroblastic sarcoma (MIFS). The patients were 15 women and 8 men, with the age ranging at the time of diagnosis from 39 to 93 years (mean, 64.3 years; median, 66 years). Follow-up was available for 18 patients, of whom 9 developed metastatic disease; 7 of these died. Most tumors showed a predilection for the soft tissues of the extremities, with 14 cases involving the lower limb and 5 the upper extremity. However, in both sites, the acral parts were affected in only 1 case each. Of the 4 remaining tumors, 2 were found in axilla, 1 was found in sacral area, and 1 developed in the scar on the breast, 14 years after previous excision of a mammary carcinoma and subsequent local irradiation. The tumor size ranged from 1.3 cm to as much as 30 cm in the largest dimension with a mean size of 8.3 cm. Histologically, the tumors were characterized by occurrence of 3 types of characteristic cells, including (1) lipoblast-like cells with an ample, distended, mucin-filled cytoplasm compartmentalized by a variable number of intracytoplasmic septa, thus remotely resembling soccer balls; (2) large, polygonal, bizarre ganglion-like cells similar to those seen in the Hodgkin disease, also called Reed-Sternberg-like cells. Within an ample, deeply eosinophilic cytoplasm, there was an oval nucleus with vesicular chromatin and a large, inclusion-like nucleolus. Binucleated, multinucleated, or more pleomorphic forms of these cells were also present; (3) cells with emperipolesis of variable sizes, ranging from very inconspicuous neoplastic cells containing only one to a few engulfed cells to conspicuous large ones having many inflammatory cells, usually polymorphonuclear leukocytes admixed with various numbers of some lymphoid cells, within the cytoplasm. Quite often, we found elements that combined the histologic features of all the above 3 characteristic tumor cell types. In 2 tumors, we found an additional undifferentiated spindle cell sarcoma component, whereas in another tumor, a chondrosarcomatous moiety was evident. For comparison, we studied 10 cases of pleomorphic hyalinizing angiectatic tumor (PHAT) of soft tissues. Based on the identification of morphological changes typical for MIFS within most of the cases of PHAT, we suggest that most cases of PHAT represent examples of MIFS merely having hyaline ectatic vessels.

TGFBR3 and MGEA5 Rearrangements in Pleomorphic Hyalinizing Angiectatic Tumors and the Spectrum of Related Neoplasms

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare, locally aggressive tumor of the distal extremities with a proclivity for local recurrence. PHATs contain characteristic ectatic, thin-walled vessels, lined by fibrin, and are surrounded by groups of variably pleomorphic spindled to epithelioid neoplastic cells. The putative precursor lesion of PHAT, originally termed "early PHAT" shares many clinicopathologic features with hemosiderotic fibrolipomatous tumor (HFLT). HFLT, myxoinflammatory fibroblastic sarcoma (MIFS), and tumors showing hybrid features of HFLT and MIFS often show TGFBR3 and MGEA5 gene rearrangements. To date, only a small number of PHATs has been tested for either rearrangement; all have been negative. We hypothesized that PHATs contain TGFBR3 and/or MGEA5 rearrangements. Cases of PHAT (all containing areas of HFLT) (N=10), HFLT (N=7), MIFS (N=6), hybrid HFLT/MIFS (N=3), and PHAT-like undifferentiated pleomorphic sarcomas (N=7) were retrieved from our institutional and consultation archives and analyzed for TGFBR3 and MGEA5 rearrangements using a break-apart probe strategy for FISH. Six of 10 PHATs harbored TGFBR3 and/or MGEA5 gene rearrangements: 4 cases had both TGFBR3 and MGEA5 rearrangements, and 2 cases contained MGEA5 rearrangements. Two of 7 HFLTs were positive: 1 case had a TGFBR3 rearrangement, and 1 case had an MGEA5 rearrangement. One of 6 MIFSs had an MGEA5 rearrangement. All 3 hybrid HFLT/MIFS cases were positive: 2 cases had both TGFBR3 and MGEA5 rearrangements, and 1 case had a TGFBR3 rearrangement. All PHAT-like undifferentiated pleomorphic sarcomas were negative. We report, for the first time, the presence of TGFBR3 and/or MGEA5 rearrangements in tumors showing mixed features of HFLT and PHAT. The presence of such rearrangements strongly suggests that HFLT is related to both PHAT and MIFS and that the latter 2 tumors may represent morphologic variants of a single, genetically defined entity in which only MIFS has acquired the capacity to metastasize.

Pleomorphic hyalinizing angiectatic tumor of soft parts: Case Report with unusual ganglion-like cells and review of the literature

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a recently described, non-metastasizing tumor of uncertain lineage. This tumor distributes equally between the genders and has a predilection for the subcutaneous soft tissue, particularly in lower extremity, other locations are rare. Based on the recent literature, PHAT is suspected to encompass the morphological spectrum with other tumors such as myxoinflammatory fibroblastic sarcoma (MIFS) and hemosiderotic fibrolipomatous tumor (HFLT), although cytogenetic data remain inconsistent. We report a case of PHAT that arose in the upper arm with unusual morphology which showed ganglion-like cells similar to Reed-Sternberg-like cells found in MIFS. The tumor had strong immunohistochemical expression of CD34, CD99, and was negative for S-100. The ganglion-like cells were positive for both CD34 and CD68 but negative for CD30. The translocation between chromosome 1 and 10, a frequent finding of MIFS and HFLT, was not identified by FISH excluding the possibility of hybrid PHAT and MIFS. We conclude FISH can be a potential useful tool to separate PHAT with atypical morphology from hybrid tumor in doubted cases. Due to the rarity of PHAT and lack of consistent pathogenetic signatures, more cases and further studies will be needed to elucidate the pathogenesis and nature of this tumor.

Pleomorphic hyalinizing angiectatic tumor arising in the thigh: A case report.

Pleomorphic hyalinizing angiectatic tumors (PHATs) are rare non-metastasizing tumors of uncertain lineage. The current study presents a case of PHAT arising in the thigh of a 68-year-old female and examines the clinicopathological characteristics of the tumor. Magnetic resonance imaging (MRI) revealed an intramuscular mass located in the adductor longus. The tumor was surrounded by lipomatous tumor. Wide resectioning was performed for the internal tumor, whereas intralesional resectioning was performed for the external tumor. Histopathologically, the internal lesion was diagnosed as a PHAT and the external lesion was diagnosed as an hemosiderotic fibrolipomatous lesion (HFLL). No recurrence or metastases were identified during the 6-year follow-up period. As the adipose tissue surrounding the PHAT resembled a HFLL, therefore, the association between ‘early PHAT’ and HFLL is discussed. Although PHATs may represent low-grade sarcomas, HFLLs may be benign tumors.

Features of Glucose Metabolism in Pleomorphic Hyalinizing Angiectatic Tumor (PHAT)

Pleomorphic Hyalinizing Angiectatic Tumor (PHAT) is a rare mesenchymal neoplasma. It is a pathological term describing a heterogeneous group of neoplasms of undetermined tumorigenesis and undefined malignancy. Based only on the morphological findings of histopathology, the biological potential of the tumor is indeterminate. Determination of glucose metabolism using FDG-PET revealed mildly increased FDG uptake in the tumor. We propose that FDG accumulation in the ectatic vessel, increased uptake of the pleomorphic cells and/or associated inflammatory cells, and increased permeability of the stroma lead to the imaging feature.

SNP array and FISH findings in two pleomorphic hyalinizing angiectatic tumors

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare soft tissue tumor of intermediate malignancy and uncertain cellular origin and lineage of differentiation. Although PHAT is still poorly characterized at the genetic level, there is a potential genetic overlap with two other soft tissue tumors: myxoinflammatory fibroblastic sarcoma (MIFS) and hemosiderotic fibrolipomatous tumor (HFLT); MIFS and HFLT share a characteristic t(1;10)(p22;q24) with breakpoints in the TGFBR3 locus on chromosome 1 and near the MGEA5 locus on chromosome 10. Recently, a PHAT with a similar t(1;10) was reported, suggesting a genetic link between MIFS/HFLT and PHAT. To ascertain whether PHAT is also associated with this translocation, two cases were subjected to single nucleotide polymorphism (SNP) array and fluorescence in situ hybridization analyses. Neither PHAT showed a t(1;10) or other types of rearrangement of the TGFBR3 or MGEA5 loci. Both tumors showed imbalances in the SNP array analysis, but none was shared. Thus, the results indicate that PHAT is genetically distinguishable from MIFS and HFLT, but further studies are needed to identify the salient genetic pathways involved in PHAT development.

CT findings of pleomorphic hyalinizing angiectatic tumor (PHAT) of soft parts of the neck

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare and recently recognized mesenchymal tumor with intermediate malignant potential, most of which arises in the soft tissue of the extremities with obvious specificity on histopathology. Here, we report a case of CT findings of PHAT arising from the posterior neck as a 3.4 × 4 × 5-cm mass in a 35-year-old woman. Precontrast CT showed an ill-defined, inhomogenous and oval-shaped mass. On contrast-enhanced CT, the mass appeared well defined except for a very small part, most of which showed marked and heterogenous enhancement, with a maximum CT value of 161 HU, which was almost identical to that of the vessels.

Pleomorphic hyalinizing angiectatic tumor: imaging findings

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare soft tissue tumor of low malignant potential, which most often arises in the lower extremities. To the best of our knowledge, there have been no prior descriptions of the imaging features of this neoplasm. In this case series, we report the imaging findings in three patients. Two patients had a lower extremity subcutaneous PHAT, while the third patient had an intramuscular upper extremity PHAT. While imaging features are variable, a diagnosis of PHAT should be considered when encountering an enhancing, subcutaneous tumor with ill-defined margins, particularly in the extremity.

Pleomorphic Hyalinizing Angiectatic Tumor

Pleomorphic hyalinizing angiectatic tumor (PHAT) is an uncommon soft tissue tumor usually located in extremities or trunk. We report 3 new cases with histopathologic diagnosis of PHAT, one with recurrence and sarcomatous myxofibrosarcoma component and another with unreported soft tissue palpebral location. Clinical data, histopathology, immunohistochemistry, fluorescence in situ hybridization, and follow-up data are described. The histopathology showed a tumor with angiectatic blood vessel proliferation and perivascular hyaline material associated with focal pleomorphic cells. The recurrent tumor revealed a histopathologic pattern corresponding to a myxofibrosarcoma. Vimentin and CD99 were positive in tumor cells and CD34 was strongly positive in the tumor cells from the recurrence. Ki-67 was poor positive but with increased positivity in the recurrence. The positivity of p53 and chromosome 22 polysomy were detected in the recurrence. At present, the 3 patients are free of disease and no metastases have been detected. Indeed, the possibility that PHAT may represent a histopathologic pattern and not a true neoplastic entity with specific genetic alterations cannot be excluded at present, and further studies are required.

Complex analysis of a recurrent pleomorphic hyalinizing angiectatic tumor of soft parts

Pleomorphic hyalinizing angiectatic tumor of soft parts is a recently recognized, low-grade mesenchymal neoplasm of uncertain lineage. It is characterized by clusters of ectatic, fibrin-lined, thin-walled vessels surrounded by pleomorphic but mitotically inert spindled cells with frequent intranuclear inclusions and a variable inflammatory component. Here, we report a case of recurrent pleomorphic hyalinizing angiectatic tumor in a 37-year-old white woman. Touch imprint cytologic analysis revealed oval and spindled cells with fine chromatin, occasional prominent intranuclear inclusions, and intracytoplasmic pigment. The histologic features of the cells constituting the bulk of tumor were those characteristic of a putative precursor lesion ("early pleomorphic hyalinizing angiectatic tumor") as well as another recently described entity known as hemosiderotic fibrohistiocytic lipomatous lesion. Cytogenetic analysis revealed 2 unbalanced translocations involving chromosomes 1 and 3 and chromosomes 1 and 10, with a karyotype of 45,XX,der(1)t(1;3)(p31;q12),-3,der(10)t(1;10)(p31;q25)[11]/46,XX[4], thus suggesting that this disease is neoplastic. The controversies in classification of these lesions are also discussed.

Pleomorphic hyalinizing angiectatic tumor of renal hilum

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a recently described rare entity. The tumor histogenesis is proposed to be of primitive undifferentiated mesenchyme. The tumor has a predilection for the subcutaneous soft tissue especially of lower extremity, although other locations have been well documented. We report a case of PHAT arising in the hilum of the kidney, clinically mimicking an infiltrating malignant neoplasm of renal pelvis. The tumor was discovered during workup for unrelated gastrointestinal tract symptoms. Because of the location of the lesion, excision of mass and radical nephrectomy were performed. The tumor had strong immunohistochemical expression of vimentin, CD34, CD99, and vascular endothelial growth factor (VEGF). No additional lesions were documented during 3 years of follow-up. This is consistent with the current thinking that PHAT is a benign neoplasm with increased incidence of recurrence. We document the unique retroperitoneal location of this rare tumor and suggest that PHAT should be considered among the list of unusual lesions at this site.

Pleomorphic hyalinizing angiectatic tumor: Cytomorphologic features on fine‐needle aspiration

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare low-grade neoplasm occurring predominantly in the subcutaneous tissue of the lower extremity, which is characterized histologically by intermixed bland spindle cells and larger pleomorphic cells, ectatic blood vessels with fibrin, and prominent hyalinization. Here we describe the cytologic features of PHAT seen on fine-needle aspiration of a right calf mass in a 46-year-old man. The smears were cellular, composed predominantly of bland spindle cells dispersed singly as well as in tissue fragments and characterized by open chromatin and small nucleoli. A second population of pleomorphic spindle cells with coarse chromatin, prominent nucleoli, and occasional intranuclear pseudoinclusions was also present. Many of the pleomorphic cells surrounded hyalizined vessels. No mitotic figures were identified. The cytologic diagnosis was a "spindle cell lesion, NOS" with the differential diagnosis including benign lesions and low-grade neoplasms, including PHAT and schwannoma.

Pleomorphic Hyalinizing Angiectatic Tumor of Soft Parts

Pleomorphic hyalinizing angiectatic tumor (PHAT) of soft parts is a rare, nonmetastasizing tumor of uncertain lineage which was first reported in 1996. Here, we report a case of PHAT and review the literature. A 49-year-old man presented with a soft and progressively enlarging mass over the right buttock for several years. On suspicion that the mass was a right gluteal lipoma, he underwent surgical excision. The excised lesion measured 14 x 6 x 3.5 cm. It had a variegated appearance with a white-tan to yellowish color on the cut surface. Some punctate hemorrhage and vessel thrombosis were seen. Microscopically, the tumor was a PHAT characterized by clusters of ectatic, fibrin-lined, thin-walled vessels, which were surrounded by a mitotically inert, spindled, pleomorphic, neoplastic stroma that contained a variable inflammatory component. Immunohistochemical study showed that the tumor cells were positive for CD34, and negative for S-100, HMB45 and actin. The patient experienced local recurrence 6 months later. The recurrent tumor was widely excised. No evidence of metastasis was found during the 18 months after the second operation. The recurrent lesion had a microscopic appearance that was similar to the initial lesion.