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

Pleomorphic hyalinizing angiectatic tumor originating in the nasal cavity: A CARE case report

INTRODUCTION

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare low-grade malignant mesenchymal neoplasm. It commonly occurs in the limbs and trunk, with limited occurrences in the head and neck region. Only five cases of PHAT occurring in the head and neck have been reported in the literature to date. The etiology of PHAT remains unclear. We described a case of nasal cavity PHAT following CARE guidelines.

CASE SUMMARY

A 32-year-old male with PHAT originating in the nasal cavity recurred after two surgeries. Adjuvant radiotherapy was performed after the third surgery. The patient has been regularly followed up for 36months, and no tumor recurrence or metastasis has been observed.

DISCUSSION

PHAT is a rare soft tissue tumor known for its local aggressiveness. Because of a high risk of recurrence, extensive resection should be implemented, possibly completed by radiotherapy if resection cannot be complete because of proximity to at-risk structures.

Pleomorphic hyalinizing angiectatic tumor of the vulva: literature review based on a rare presentation

Pleomorphic hyalinizing angiectatic tumor (PHAT) of soft tissues is a rare, non-metastatic tumor of unknown etiology and uncertain behavior, which may recur locally. There are few reports on this condition, and due to the rarity of the disease, its lineage has not yet been fully elucidated. The present study aims to report the case of an unusual entity observed for the first time in vulval topography. A female patient, 83 years old, presented with a tumor in the vulvar region that had evolved for approximately 4 months. Magnetic resonance imaging showed an expansive perineal formation of 8.5 × 3.5 cm, and a hemivulvectomy with a flap rotation was performed. The review of the slides revealed a mesenchymal lesion without significant atypia, which was richly vascularized. In the areas of interest, the immunohistochemical (IHC) study demonstrated positivity for CD34, estrogen, and progesterone receptors; it was negative for the other tested markers. Morphological findings associated with the IHC staining panel supported the diagnosis of PHAT. The main morphological features of PHAT are clusters of ectatic vessels of different sizes that show deposits of subendothelial and intraluminal fibrin. Fusiform and pleomorphic cells randomly arranged in leaves or long fascicles intermingle these vessels. It is essential to recognize this entity and consider it among the differential diagnoses of a mesenchymal lesion, given the wide variety of entities that comprise this group of lesions.

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.

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.

Imaging and histological appearance of pleomorphic hyalinizing angiectatic tumors: A case series and literature review

Pleomorphic hyalinizing angiectatic tumors (PHATs) are rare mesenchymal soft tissue tumors of uncertain lineage and intermediate malignancy. The present study assesses two cases of PHAT and discusses the histological and immunophenotypical features, as well as the imaging appearance of these tumors on ultrasound, computed tomography (CT), magnetic resonance imaging and positron emission tomography/CT scans. The current study also reviews the literature and discusses the clinical management of these tumors. Wide local excision with tumor free margins is the current recommended treatment for PHAT. Surgical excision may be combined with low-dose radiation to reduce the risk of local recurrence. Patients should be followed up with serial imaging, as PHAT lesions tend to recur locally.

Treatment modalities and outcomes of pleomorphic hyalinizing angiectatic tumor: a systematic review of the literature

A systematic review of the cases documented in the literature regarding Pleomorphic hyalinizing angiectatic tumor of soft parts (PHAT) was performed in order to identify (1) location on presentation (2) surgical treatment modality (3) recurrence rate (4) any associations between location, age, histology, surgery type on recurrence. A systematic review of medical literature listed on PubMed was conducted identifying any prior case report and/or case series of diagnosed PHAT, with no exclusion based on language or time. Twenty-nine articles were identified removing any articles with duplicated cases yielding a total of 93 cases. Cases were broken down by gender, presenting location (UE/LE/axial), surgery type [wide local resection, non-wide local, wide local with radiation therapy (RT), non-wide local with RT], recurrence, and time to recurrence. The mean age at presentation was 54.5 ± 17.1 (range 10-89) with the 76% of cases appearing in the lower extremity (15% UE, 9% Axial). Of the 93 patients, 74 had a known surgical procedure, 31% WL, 40% NWL, 8% WL + RT, 1% NWL + RT. Of those treated surgically, 63 pts had documented follow-up and 18 (29%) had recurrence. A strong association was observed between surgery type and recurrence. Local recurrence was more common within the group undergoing NWLE in 52% (16/41) of cases (p = 0.002). Kaplan-Meier analysis showed an estimate mean time for recurrence of 43.87 months [95% confidence interval (CI) 24.52-63.22; and standard error (SE) 7.59] for the entire population. A trend was also seen toward males having a shorter disease-free survival than females (29.4 mos. vs. 69.5 mos.). No significant association seen between size, location, histology type and recurrence. PHAT has a characteristic presentation in the LE with a relatively high rate of local recurrence and slow-growing potential. Wide local excision appears to be superior in decreasing recurrence rates and a long-term follow-up period is needed.

Pelvic retroperitoneal pleomorphic hyalinizing angiectatic tumor (PHAT) of soft tissue: a case report

Background

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare soft tissue tumor of low malignant potential, which most often arises in the lower extremities. Lesions occurred in other anatomic locations have been rarely reported. Moreover, their imaging features have not been well discussed. Here we report a case of PHAT arising primarily in the pelvic retroperitoneum. To our knowledge, this is the first radiological description for retroperitoneum PHAT.

Case presentation

A 26-year-old female was referred to our hospital for evaluation of a pelvic mass incidentally noted in routine pre-pregnancy ultrasonography examination. Magnetic resonance imaging (MRI) and computed tomography (CT) scan revealed an irregular mass with clear boundary in the pelvic retroperitoneum. Its signal intensity or density was inhomogeneous. On MRI images, it mainly showed isointense and slight hypointense on T1 weighted image and isointense and hyperintense on T2 weighted image. On contrast-enhanced images, it showed marked but heterogenous enhancement. With the delay time increasing, the enhanced area in the lesion increased but the CT value decreased. Dilated vessels and hemorrhage were detected in the tumor. With patience and careful separation, it was completely excised with great amount of bleeding during operation. Pathological and immunohistochemistry analysis confirmed the diagnosis of PHAT of the soft parts. We found no evidence of recurrence 18 months after operation.

Conclusion

We present an extremely rare case of PHAT arising primarily in the pelvic retroperitoneum. To our knowledge, this is the first radiological description for retroperitoneum PHAT. The provided information is useful for summarizing the characteristics of this kind of tumor. It should be included in the differential diagnosis of a well-defined, inhomogenously enhanced hypervascular soft-tissue mass in pelvic cavity.