Intramuscular capillary-type hemangioma: radiologic-pathologic correlation

Soft tissue vascular tumor-like lesions in adults: imaging and pathological analysis pitfalls per ISSVA classification

OBJECTIVES

To compare the magnetic resonance imaging (MRI) and Doppler ultrasound (DUS) findings with the pathological findings of soft tissue vascular tumors (STVTs) according to the 2018 ISSVA (International Society for the Study of Vascular Anomalies) classification to differentiate vascular tumors from vascular malformations.

METHODS

This retrospective study included patients with STVTs who underwent contrast-enhanced MRI and pathological analysis at our hospital between 2010 and 2020. The presumptive diagnosis based on the on-site imaging and histological analysis was compared with imaging and histological analysis conducted off-site utilizing the ISSVA criteria.

RESULTS

This study included 31 patients with 31 vascular tumors located in the head and neck (n = 3), trunk (n = 2), and extremities (n = 26). The off-site pathological analysis confirmed benign vascular tumors in 54.8% of cases (non-involuting congenital hemangioma: 35.5%; epithelioid hemangioma: 13%; pyogenic granuloma: 3%; and spindle cell hemangioma: 3%). Based on the off-site histological analysis, 25.8% were reclassified as having a vascular malformation whereas three had other benign lesions. Only phleboliths were associated with a vascular malformation (p = 0.03). The concordance between off-site MRI and pathological findings was fair (k = 0.3902 (0.0531-0.7274)), whereas that between on-site and off-site pathological analyses was poor (k = -0.0949 (-0.4661 to 0.2763)).

CONCLUSION

Benign vascular tumors have non-specific imaging features on imaging with some overlap with atypical vascular malformations. Therefore, histological analysis is recommended. Imaging and pathological analyses should be performed in accordance with the ISSVA classification to minimize inter-observer discrepancies.

CRITICAL RELEVANCE STATEMENT

Imaging features of benign vascular tumors on MRI are non-specific, leading to discrepancies with pathological findings and potential overlap with atypical vascular malformations. Imaging and histological analyses should be performed in accordance with ISSVA guidelines to improve patient management.

KEY POINTS

The imaging features of benign vascular tumors are non-specific. Histological analysis is recommended for soft tissue vascular tumors in adults. Analyses of soft tissue vascular tumors should be performed in accordance with ISSVA guidelines.

Summary of the application value of ultrasound imaging features in the clinical differential diagnosis of intramuscular capillary-type hemangioma and fibro-adipose vascular anomaly

Objective

To investigate the value of ultrasonography as a diagnostic aid in differentiating intramuscular capillary-type hemangioma (ICTH) from fibro-adipose vascular anomaly (FAVA).

Methods

A retrospective analysis was conducted of the clinical and ultrasound imaging data of 20 patients with ICTH and 45 patients with FAVA who were admitted to and pathologically confirmed in hospital between January 2013 and April 2023. The clinical and ultrasonographic appearances of the lesions in the two groups were compared and analyzed. A stepwise regression analysis was performed, and a joint diagnostic equation was constructed using the final variables selected. The receiver operating characteristic (ROC) curve and indicators, including sensitivity and specificity, were used to evaluate the efficacy of the joint diagnostic model.

Results

The two groups of patients suffering from ICTH and FAVA presented a statistically significant difference (P< 0.05) in terms of 'age', 'lesion size', 'fascial tail sign', 'presence of a fatty-tissue-like hyperecho around the lesion', 'blood flow' and 'presence of straight blood capillaries within the lesion'. Finally, the variables 'fascial tail sign' and 'presence of straight blood capillaries within the lesion' were selected to construct the model. The constructed joint diagnostic model had a sensitivity value of 70.0% (95% CI: 59.00-81.00), a specificity value of 98.0% (95% CI: 94.70-100.00) and a ROC curve value of 0.908, indicating the high efficacy of the combined diagnosis method.

Conclusions

Ultrasonography can be utilized to differentiate ICTH from FAVA, and the combined diagnosis method can further improve the technique's diagnostic efficacy.

Intramuscular capillary-type hemangioma: Diagnosis, treatment, and outcomes. A French multicentric retrospective study of 66 cases

PURPOSE

Intramuscular capillary-type hemangiomas (ICTHs) are rare entities, belonging to the group of intramuscular "hemangiomas." The diagnosis remains challenging. We aimed to assess the diagnostic criteria, treatments and outcomes of ICTHs.

METHODS

This retrospective study collected all cases of ICTH followed up in 9 French hospital centers, reviewed by an adjudication expert group.

RESULTS

Among 133 patients screened, 66 with ICTH were included. The median age of patients at diagnosis was 28.0 years, interquartile range (21.0---36.0). The lesion, mainly presenting as a gradually increasing mass (83.9%), was painless (88.9%) and was located in the head and neck (42.4%). MRI (available in all cases) mainly revealed a well-delineated lesion, isointense to the muscle on T1-weighted images, with enhancement after contrast injection; hyperintense on T2-weighted images; and containing flow voids. Among the 66 cases, 59 exhibited typical ICTH features and 7 shared some imaging features with arteriovenous malformations. These latter were larger than typical ICTHs and more painful and appeared on imaging as less well delimited and more heterogeneous tissue masses, with larger tortuous afferent arteries, earlier draining vein opacification and mild arteriovenous shunting. We propose to name these lesions arteriovenous malformation (AVM)-like ICTH. Pathological reports were similar in typical and AVM-like ICTH, showing capillary proliferation with mainly small-size vessels, negative for GLUT-1 and positive for ERG, AML, CD31 and CD34, with low Ki67 proliferation index (<10%), and adipose tissue. The most frequent treatment for ICTH was complete surgical resection (17/47, 36.2%), preceded in some cases by embolization, which led to complete remission.

CONCLUSIONS

ICTH can be diagnosed on MRI when it is typical. Biopsy or angiography are required for atypical forms.

Fat-Containing Soft Tissue Tumors in Children, Adolescents, and Young Adults: Which Require Biopsy?

PURPOSE

To confirm the overall benignity of fat-containing soft tissue tumors (STT) on a pediatric cohort and to define the clinical and imaging features that warrant a biopsy.

METHODS

A retrospective monocentric study was conducted on patients aged less than 25 years consecutively referred for fat-containing STT to our Comprehensive Cancer Center between 1998 and 2022. Tumor imaging characteristics at diagnosis (US, CT, or MRI) were correlated with pathology.

RESULTS

The database extraction identified 63 fat-containing tumors with clinical, histologic, and imaging data available for review. In total, 58 (92%) were benign tumors: 36 lipoblastomas and lipomas, 12 fibrous hamartomas of infancy (FHI), 5 lipofibromatosis, 2 lipomas arborescens, 2 lipomatosis and 1 spindle-cell lipoma. Five patients (8%) were diagnosed with liposarcoma. Factors significantly correlated with malignancy were age >10 years old (p < 0.001), having a cancer-predisposing condition (p < 0.001), a percentage of fat <25% (p = 0.002), and a presence of myxoid zones (p < 0.001) on imaging.

CONCLUSION

Most fat-containing STT in children may be classified as benign tumors based on clinics and imaging. The indication for biopsy could be limited to patients aged 10 years or more with either a cancer-predisposing condition or imaging features demonstrating either a low-fat component (<25%) or the presence of myxoid zones.

Characteristics, Natural Course and Treatment of Intramuscular Capillary-type Haemangioma: A Systematic Literature Review

Intramuscular capillary-type haemangiomas (ICTH) are rare vascular anomalies that can easily be misdiagnosed as other entities. A systematic review was performed of all cases of ICTH in the literature since its first description in 1972. An adjudication committee reviewed cases to include only ICTHs. Among 1,143 reports screened, 43 were included, involving 75 patients. The most frequent differential diagnosis was intramuscular venous malformations. The mean age of patients at diagnosis was 21.2 years. ICTH was mainly described as a gradually increasing mass (81.8%), painless (73.9%), that could occur anywhere in the body but most frequently on the head and neck (44.0%). Magnetic resonance imaging (MRI) was mainly used for diagnosis (69.1%) and displayed specific features. The most frequent treatment was complete surgical removal (73.9%), which could be preceded by embolization, and led to complete remission without recurrence in all but 1 case.

Vascular anomalies: diagnostic features and step-wise approach

The first part of this review article emphasized correct nomenclature, classification systems, and imaging algorithm of vascular anomalies. The second part of the review discusses the individual entities, highlighting the characteristic clinico-radiological features of the commonly encountered ones. A step-wise algorithmic approach is also proposed for the evaluation of a suspected case of vascular anomaly.

The Challenges of Upper Extremity Intramuscular Hemangioma: a Case Study and Systematic Review

BACKGROUND

Intramuscular hemangiomas (IMHs) are rare, benign vascular tumors, comprising 0.8% of all hemangiomas. Upper extremity (UE) IMHs pose diagnostic and therapeutic challenges given their rarity, invasive nature, and potential for neurovascular involvement. We report a comprehensive systematic review of UE IMH management and a challenging case report.

METHODS

A systematic review was performed using PRISMA guidelines. Electronic databases were used to identify papers describing UE IMHs through 2019. Patient demographics, clinical presentation, management, complications, and outcomes were reviewed. Based on operative timing, cases were categorized as either "primary" (excision performed at initial diagnosis) or "secondary" (excision performed after failure of conservative treatment).

RESULTS

Eighteen articles encompassing 25 patients were included in our systematic review. Of those, 18 underwent primary excision and 7 underwent secondary excision. The majority involved the forearm or antecubital region. Complete excision, evaluated by gross examination or pathology, was reported in all primary cases and 71% secondary cases. Primary excisions demonstrated smaller mass size (19.4cm2 versus 165.3cm2) and superior reported functional outcomes (100% versus 33%). Complications were reported in 5% of the primary excisions compared to 71% of the secondary excisions, where 1 complication was a fatal hematoma.

CONCLUSION

The literature concerning UE IMH is limited to mostly case reports and several case series with the potential risk of bias. With careful dissection and microsurgical technique, wide local excision followed by complete reconstruction can be successfully performed at initial diagnosis for UE IMHs. At early stages, smaller lesion size significantly reduces the risk of functional impairment and complications.

Ultrasound imaging as an initial diagnostic method for intramuscular hemangiomas: a narrative review

Intramuscular hemangiomas are benign vascular lesions, often misdiagnosed due to unfamiliarity. They are rare (but not very rare) causes of musculoskeletal pain and diagnosing these tumors may be challenging because of their pertinent non-specific symptomatology. Herein, as a convenient imaging tool, ultrasound examination appears to an important initial method to scan for these lesions after the clinical examination. To date, there are no studies that examined the state-of-the-art as regards the use of ultrasound imaging in the diagnosis of intramuscular hemangiomas. Accordingly, a literature search was performed using PubMed and Web of Science with the purpose to provide a conceptual understanding and awareness as regards the importance/utility of ultrasound imaging as a first step diagnostic tool for intramuscular hemangiomas at different muscles' locations.

Intramuscular Hemangioma of Masseter Muscle: Case Report of Rare Clinical Entity

Rationale:

Intramuscular hemangiomas are unique benign vascular tumours of skeletal muscles; involving masseter and trapezius muscles in the majority of cases. The rationale was to emphasize that the diagnosis of asymptomatic swelling in the masseteric region is important as due to their deep anatomic location and unfamiliar presentation, they are often misdiagnosed as a parotid swelling or other muscular pathologies.

Patient Concern:

This report describes a rare case of a 25-year-old healthy male patient who presented with an asymptomatic swelling in the right masseteric region. The patient had cosmetic concerns due to the large size.

Diagnosis:

Colour Doppler ultrasonography was done to assess the vascularity within the lesion.

Treatment:

Complete excision was successfully achieved using combined Risdon's and preauricular approach.

Outcome:

No signs of recurrence were observed after 6 months

Take-away Lessons:

Appropriate selection of diagnostic modalities enables the clinician in making an accurate preoperative diagnosis of progressive swelling in the masseteric region.

Newcomers in Vascular Anomalies

Vascular anomalies are composed of tumors and malformations and with overlapping histologies, thus are often misdiagnosed or labeled with imprecise terminology. Lesions are common and usually diagnosed during infancy or childhood; the estimated prevalence is 4.5%. Vascular tumors rapidly enlarge postnatally and demonstrate endothelial proliferation. Malformations are errors in vascular development with stable endothelial turnover; they are typically named based on the primary vessel that is malformed (capillary, arterial, venous, lymphatic). This article reviews the pathologic and molecular genetic characteristics for select recently described vascular anomalies.

Imaging of intramuscular haemangiomas of the extremities

Intramuscular haemangiomas are benign soft tissue tumours that are more frequently seen in children and young adults. As they may be difficult to diagnose clinically, imaging has an important role in the detection, diagnosis and preoperative planning of these lesions. Haemangiomas of the extremities may be classified into capillary, cavernous, venous and mixed types, with or without an arteriovenous shunt, depending on the predominant vascular channels. Nonvascular components such as fat, smooth muscle, fibrous tissue and thrombus may also be present. This pictorial essay highlights the imaging features of intramuscular haemangiomas, with an emphasis on magnetic resonance imaging.

Sonography of pediatric gastrointestinal venous malformations

Gastrointestinal (GI) venous malformations are extremely rare. Such malformations present in the pediatric age group and can occur anywhere in the digestive tract (esophagus, stomach, small or large intestine, anus, and mesentery). We present the sonographic findings of three cases of pediatric GI venous malformation. Sonography is an important diagnostic method in pediatric GI venous malformations.

[Classification of vascular tumours and vascular malformations. Contribution of the ISSVA 2014/2018 classification]

The study of vascular anomalies, "angiomas", vascular tumours and vascular malformations is made difficult by the great variety and confusion of the names used in the literature for these diseases, some of which are rare. The great merit of the classification proposed by the International Society for the Study of Vascular Anomalies (ISSVA), adopted in 2014 and modified in 2018, is to propose a unambiguous nomenclature and to try to group these lesions in a logical way, contrasting with the lists of the usual "classifications". This classification is based on the distinction between proliferative lesions (tumours and reactive lesions) and those which are due to a congenital anomaly of vascular morphogenesis (vascular malformations). It incorporates recent data on the molecular causes of these diseases. The major groups of lesions recognised in this classification will be presented and some lesions of interest briefly discussed. This classification aims to be usable by all medical specialties and applicable to all tissues and organs, even if efforts are still needed to integrate organ-specific names in order to unify the nomenclature and eliminate confusion. Even if it does not solve all the problems in this complex field, the unification of the nomenclature is a major contribution of this classification and pathologists are strongly encouraged to refer to it in daily practice.

Three Distinct Vascular Anomalies Involving Skeletal Muscle: Simplifying the Approach for the General Radiologist

Venous malformations and hemangiomas of the skeletal muscle are separate entities with different clinical presentation, histology, and imaging findings. Recent advances in the field of vascular anomalies and current efforts in the unification of terminology by the International Society for the Study of Vascular Anomalies are pivotal in understanding and differentiating intramuscular venous malformations and intramuscular capillary-type hemangioma. Fibroadipose vascular anomaly is another recently defined vascular anomaly affecting the skeletal muscle, with a distinct clinical presentation, histology, and imaging appearance. These 3 distinct vascular anomalies are reviewed and their histologic features, clinical presentation, imaging appearance, and treatment are discussed.

Intramuscular fast-flow vascular anomaly contains somatic MAP2K1 and KRAS mutations

BACKGROUND

The term "intramuscular hemangioma capillary type" (IHCT) refers to a fast-flow vascular lesion that is classified as a tumor, although its phenotype overlaps with arteriovenous malformation (AVM). The purpose of this study was to identify somatic mutations in IHCT.

METHODS

Affected tissue specimens were obtained during a clinically indicated procedure. The diagnosis of IHCT was based on history, physical examination, imaging and histopathology. Because somatic mutations in cancer-associated genes can cause vascular malformations, we sequenced exons from 446 cancer-related genes in DNA from 7 IHCT specimens. We then performed mutation-specific droplet digital PCR (ddPCR) to independently test for the presence of a somatic mutation found by sequencing and to screen one additional IHCT sample.

RESULTS

We detected somatic mutations in 6 of 8 IHCT specimens. Four specimens had a mutation in MAP2K1 (p.Q58_E62del, p.P105_I107delinsL, p.Q56P) and 2 specimens had mutations in KRAS (p.K5E and p.G12D, p.G12D and p.Q22R). Mutant allele frequencies detected by sequencing and confirmed by ddPCR ranged from 2 to 15%.

CONCLUSIONS

IHCT lesions are phenotypically similar to AVMs and contain the same somatic MAP2K1 or KRAS mutations, suggesting that IHCT is on the AVM spectrum. We propose calling this lesion "intramuscular fast-flow vascular anomaly."

Clinical and sonographic features of pediatric soft-tissue vascular anomalies part 1: classification, sonographic approach and vascular tumors

Sonography can be used in the management of pediatric soft-tissue vascular anomalies for diagnosing, for assessing lesion extent and for evaluating complications and response to therapy. The sonographic technique includes a combination of gray-scale imaging with color and spectral Doppler techniques. However the interpretation of the sonographic findings requires correlation with the clinical findings, some of which can be easily obtained at the time of scanning. This has to be combined with the use of appropriate nomenclature and the most updated classification in order to categorize these children into the appropriate management pathway. In this article, which is part 1 of a two-part series, the authors review the current classification of vascular anomalies, provide a clinical and a sonographic approach to these lesions, and review the most relevant clinical and sonographic features of vascular tumors including infantile and congenital hemangiomas, tufted angioma, kaposiform hemangioendothelioma, pyogenic granuloma, intramuscular capillary-type hemangioma and angiosarcoma.

Intramuscular hemangiomas on the masseter muscle and orbicularis oris muscle: a report of two cases

Intramuscular hemangioma (IMH) is a rare vascular disease involving skeletal muscle, comprising only 0.8% of hemangiomas. About 10% to 15% of IMHs occur in the head and neck region, mostly involving the masseter muscle. IMH occurs mostly in childhood, but is often not found until unexpected enlargement, pain, or cosmetic asymmetry occurs in adulthood. Several non-surgical treatments including cryotherapy, sclerosant injection, and arterial ligature have been described, but complete surgical resection is the curative intervention. In this report, we present two rare cases of IMH. One IMH case in a 48-year-old male occurred in the masseter muscle feeding from the transverse facial artery. Embolization of the distal branch of the facial artery was first conducted, and then the buccal mass was removed surgically via the intraoral approach. A second IMH case in a 58-year-old female occurred in the orbicularis oris muscle feeding from the superior labial artery, and the mass was excised surgically without embolization.

Fat-containing soft-tissue masses in children

The diagnosis of soft-tissue masses in children can be difficult because of the frequently nonspecific clinical and imaging characteristics of these lesions. However key findings on imaging can aid in diagnosis. The identification of macroscopic fat within a soft-tissue mass narrows the differential diagnosis considerably and suggests a high likelihood of a benign etiology in children. Fat can be difficult to detect with sonography because of the variable appearance of fat using this modality. Fat is easier to recognize using MRI, particularly with the aid of fat-suppression techniques. Although a large portion of fat-containing masses in children are adipocytic tumors, a variety of other tumors and mass-like conditions that contain fat should be considered by the radiologist confronted with a fat-containing mass in a child. In this article we review the sonographic and MRI findings in the most relevant fat-containing soft-tissue masses in the pediatric age group, including adipocytic tumors (lipoma, angiolipoma, lipomatosis, lipoblastoma, lipomatosis of nerve, and liposarcoma); fibroblastic/myofibroblastic tumors (fibrous hamartoma of infancy and lipofibromatosis); vascular anomalies (involuting hemangioma, intramuscular capillary hemangioma, phosphate and tensin homologue (PTEN) hamartoma of soft tissue, fibro-adipose vascular anomaly), and other miscellaneous entities, such as fat necrosis and epigastric hernia.

The histological variants of liposarcoma: predictive MRI findings with prognostic implications, management, follow-up, and differential diagnosis

Liposarcoma is the single most common soft tissue sarcoma accounting for up to 35 % of sarcomas. It represents a histologically diverse group of soft tissue tumors that demonstrate a wide range of imaging appearances with varied behavior patterns. Correspondingly, more aggressive histological subtypes often require management that includes a combination of surgery, chemotherapy, and radiation therapy. Distinguishing among liposarcoma subtypes has important therapeutic and prognostic implications. In this manuscript, we review the liposarcoma subtypes and their histologic and MRI findings, prognostic implications, and differential diagnostic considerations.

Magnetic resonance imaging of pediatric soft-tissue vascular anomalies

Magnetic resonance (MR) imaging can be used in the management of pediatric soft-tissue vascular anomalies for diagnosing and assessing extent of lesions and for evaluating response to therapy. MR imaging studies often involve a combination of T1- and T2-weighted images in addition to MR angiography and fat-suppressed post-contrast sequences. The MR imaging features of these vascular anomalies when combined with clinical findings can aid in diagnosis. In cases of complex vascular malformations and syndromes associated with vascular anomalies, MR imaging can be used to evaluate accompanying soft-tissue and bone anomalies. This article reviews the MR imaging protocols and appearances of the most common pediatric soft-tissue vascular anomalies.

Atypical MRI features in soft-tissue arteriovenous malformation: a novel imaging appearance with radiologic-pathologic correlation

BACKGROUND

The absence of a discrete mass, surrounding signal abnormality and solid enhancement are imaging features that have traditionally been used to differentiate soft-tissue arteriovenous malformations from vascular tumors on MRI. We have observed that these findings are not uncommon in arteriovenous malformations, which may lead to misdiagnosis or inappropriate treatment.

OBJECTIVE

To estimate the frequency of atypical MRI features in soft-tissue arteriovenous malformations and assess their relationship to lesion size, location, tissue type involved and vascular architecture.

MATERIALS AND METHODS

Medical records, MRI and histopathology were reviewed in consecutive patients with soft-tissue arteriovenous malformations in a multidisciplinary vascular anomalies clinic. Arteriovenous malformations were divided into those with and without atypical MRI findings (perilesional T2 signal abnormality, enhancement and/or a soft-tissue mass). Lesion location, size, tissue involved and vascular architecture were also compared between groups. Tissue stains were reviewed in available biopsy or resection specimens to assess relationships between MRI findings and histopathology.

RESULTS

Thirty patients with treatment-naïve arteriovenous malformations were included. Fifteen lesions demonstrated atypical MRI. There was no difference in age, gender, lesion size or involved body part between the groups. However, more than half of the atypical lesions demonstrated multicompartmental involvement, and tiny intralesional flow voids were more common in atypical arteriovenous malformations. Histopathology also differed in atypical cases, showing densely packed endothelial cells with connective tissue architectural distortion and edema.

CONCLUSION

Arteriovenous malformations may exhibit features of a vascular tumor on MRI, particularly when multicompartmental and/or containing tiny internal vessels. These features are important to consider in suspected fast-flow vascular malformations and may have implications with respect to their treatment.