Myopericytoma of the kidney

A Rare Tumor of Intravascular Myopericytoma in the Right Renal Vein

Myopericytoma, a perivascular myoid neoplasm, is commonly found in the dermis or subcutaneous tissues; however, its occurrence in visceral organs is unusual. Here, we present an extremely rare tumor of intravascular myopericytoma of the right renal vein. A 44-year-old man was incidentally diagnosed with a mass in the right kidney during a routine checkup. A nephrectomy was performed because the urologist suspected renal cancer. A gross examination of the resected specimen revealed a well-circumscribed brown mass in the renal hilum. Histologically, the tumor showed a concentric multilayered proliferation of spindle cells surrounding blood vessels. Immunohistochemical staining showed that the spindle-shaped tumor cells were negative for desmin but positive for α-smooth muscle actin and h-caldesmon, indicating their myoid nature. We confirmed that the tumor was located in the right renal vein because it was encased within a thick wall that was desmin-positive and contained elastic fibers, as shown by Elastica van Gieson staining. The patient was diagnosed with an intravascular myopericytoma of the right renal vein. There are several differential diagnoses for renal mesenchymal tumors, including angiomyolipoma. This emphasizes the importance of considering these uncommon tumors when examining nephrectomy specimens.

Myopericytoma of the ureter Incidental finding of a benign slowly growing tumor

We present a unique case of a 6 cm, incidental, ureteral myopericytoma which was initially believed to be an ovarian tumor with mass effect, causing hydroureteronephrosis. A 75-year-old woman presented with a three-month history of postprandial cramps and heartburn. A right distal ureterectomy with en-bloc resection of the mass was performed. Histologically, a well-circumscribed, cellular proliferation of uniform, cytologically bland, spindle cells was identified that had a multilayered, concentric growth pattern around numerous blood vessels. Immunohistochemically, the spindle lesional cells stained strongly and diffusely with antibodies against smooth muscle actin and failed to stain for pancytokeratin and S100 protein.

Primary hepatic myopericytoma coexisting with multiple cystic hepatic lesions: a case report

BACKGROUND

Hepatic myopericytoma (MPC) is an extremely rare pathological entity in the liver. Conversely, cystic hepatic lesions are a group of heterogeneous lesions encountered commonly in daily practice. Here, we report a unique case of the coexistence of primary hepatic MPC and multiple cystic hepatic lesions along with our perceptions on its diagnosis and treatment.

CASE PRESENTATION

A 56-year-old female patient was found to have a left liver mass during a routine physical examination. Computer tomography (CT) and magnetic resonance imaging (MRI) confirmed the existence of a left hepatic neoplasm along with multiple hepatic cysts but could not exclude the possible malignant nature of the neoplasm. Computer tomography (CT) also identified an enlarged mediastinal lymph node with a maximum diameter of 4.3 cm, which further underwent core needle biopsy under CT guidance. A histopathological examination was performed to rule out malignancy. Afterwards, the patient underwent left hemihepatectomy to resect a solid tumor of 5.5 cm × 5 cm × 4.7 cm with multiple cystic lesions which were histopathologically examined to establish the diagnosis of myopericytoma with hepatic cysts. Postoperatively, the patient recovered from the surgery quickly without significant adverse events and was not found to have a reoccurrence of the primary pathological entity.

CONCLUSIONS

This is the first reported case of a patient with the co-existence of primary hepatic myopericytoma and multiple cystic hepatic lesions undergoing surgical treatment with eventual recovery.

Rare Case of Intravascular Myopericytoma-Imaging Characteristics and Review of the Literature

Myopericytoma is a rare vessel wall tumor, a subtype of hemangiopericytoma that usually develops subcutaneously. Intravascular myopericytoma is a rarer subtype, with only few cases reported in the literature and even fewer with imaging modalities included. We report the case of a 36-year-old man who was referred to our institution with a painless, palpable mass in the right arm and was evaluated with MRI, grey-scale and Doppler-mode ultrasound. Tumor histopathology and imaging characteristics are presented together with the role that each imaging modality played in the management of the patient.

Thoracic myopericytoma in an older adult, rare but possible: A case report

Myopericytoma is a rare tumor generally arising from skin and soft tissues of extremities, trunk, head, and neck regions, rarely from visceral sites. An intrathoracic visceral localization may carry a broad differential diagnosis including primary lung, pleura and chest wall lesions, or metastatic lesions. To date, any radiological features have been recognized and diagnosis of myopericytoma with intrathoracic localization remains still challenging. Here, we describe the case of a subpleural lesion incidentally diagnosed in an older adult affected by gastric cancer. Radiological features did not allow a differential diagnosis between a benign lesion, a primary tumor, or a metastasis. After resection, the histological examination showed histopathological features congruent with the diagnosis of myopericytoma. This unusual presentation reflects the need to share clinical, radiological, and histopathological data about this uncommon but frequently misdiagnosed disease.

Ankle Myopericytoma: A Rare Case Report and Cytogenetic Study

Myopericytoma (MPC) is an uncommon benign neoplasm of the skin and soft tissues belonging to a spectrum of tumors that are histologically recognized by their distinctive perivascular myoid cell differentiation. These distinct tumors are more prevalent among middle-aged males, and they arise more frequently in the subcutaneous tissue of the four extremities. In this paper, myopericytoma is reported in a 59-year-old Saudi male, presented with a painless small cyst involving the left ankle suspected clinically to be a ganglion cyst. Following surgical excision of the cyst, the diagnosis of myopericytoma was made based on the histopathological pattern of the disease. This paper focuses on the clinical and histopathological findings of myopericytoma and emphasizes the importance of immunohistochemistry as well as molecular testing in reaching the final diagnosis.

A retroperitoneal myopericytoma: The first case located at the retroperitoneal area and not originate from the kidneys

A 25-year-old woman had a mass of approximately 65 cm × 33 cm × 102 cm, located in the left paraaortic area on CT scan. It was diagnosed as retroperitoneal malignant neoplasm on imaging. Afterward, open retroperitoneal tumor excision was performed. At laparotomy, the mass was carefully dissected from the ureter, renal artery, and aorta and excised as en-bloc. The pathological result was "myopericytoma." Histologically, the pathological findings characterized a pericytic neoplasm characterized by a perivascular growth of myoid tumor cells. In addition, there were uniform, oval-shaped cells with eosinophilic cytoplasm arranged in short fascicles around blood vessels. The cytologic atypia and mitoses were absent. There are many different tumors in the retroperitoneal area. Most of these lesions are malign nature. Nevertheless, for each benign and malign neoplasm, the preoperative imaging method is generally similar. This present case showed the significant findings of myopericytoma, a benign pathology located in the retroperitoneal area.

Cancer diagnosis and analysis devices based on multimolecular crowding

The study of the multimolecular crowding around cancer cells has opened up the possibility of developing new devices for cancer diagnosis and analysis through the measurement of intercellular communication related to cell proliferation and invasive metastasis associated with cancer malignancy. In particular, cells and extracellular vesicles that flow into the bloodstream contain metabolites and secreted products of the cancer microenvironment. These are positioned as targets for the development of new devices for the understanding and application of multimolecular crowding around cancer cells. Examples include the separation analysis of cancer cells in blood for the next generation of less invasive testing techniques, and mapping analysis using Raman scattering to detect cancer cells without staining. Another example is the evaluation of the relationship between exosomes and cancer traits for the exploration of new anti-cancer drugs, and the commercialization of exosome separation devices for ultra-early cancer diagnosis. The development of nanobiodevice engineering, which applies multimolecular crowding to conventional nanobioscience, is expected to contribute to the diagnosis and analysis of various diseases in the future.

Myopericytoma-like tumors of the lung: Report of two cases

Myopericytoma is a benign neoplasm presenting cells with different shapes, from oval to spindle, and myoid showing with perivascular growth, which frequently originates from the skin and soft tissues of distal extremities, trunk, head, and neck regions. These tumors rarely have been reported to occur in visceral sites. There is only one case of myopericytoma showing pulmonary involvement with multiple nodules. Although most myopericytomas behave in a benign manner, some cases of malignant myopericytoma arising in both superficial soft tissue and visceral locations have been described. We describe two cases of pulmonary tumors with myopericytoma-like features.

Renal myopericytoma: A case report and literature review

Renal myopericytoma is an extremely rare entity with just 11 cases reported in the literature. We report the case of a 57 year old Caucasian man who was found to have a renal myopericytoma following nephrectomy for suspected renal cell carcinoma. Renal myopericytoma has a distinct morphological overlap with other pericytic tumours and significant histological variation has been noted between cases reported to date. Further characterising this novel tumour is vital to identify subtypes within this spectrum, understand its behaviour and to identify imaging trends which may lead to pre-operative diagnosis in order to potentially avoid radical treatment.

Imaging performance and preoperative differential diagnosis of multiple myopericytoma in the liver: A case report

Myopericytoma is a rare type of benign tumor, which commonly affects all four limbs. The occurrence of myopericytoma in the liver is extremely rare. Myopericytoma with a size of >1 cm in diameter in the liver has not been previously reported. Due to the limited number of cases, the preoperative diagnosis of liver myopericytoma based on laboratory and imaging examinations is difficult. In the present case report, a patient with multiple myopericytoma in the liver, with a maximum diameter of 4.5 cm was described, with accompanying computed tomography (CT) and positron emission tomography/CT (PET/CT) imaging profiles. The aim of the present report was to discuss the preoperative differential diagnosis between myopericytoma and other common liver neoplasms, such as intrahepatic cholangiocarcinoma or liver metastasis.

A rare pericytic tumor of the kidney: The first case in Korea

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The family of pericytic tumors includes glomus tumors and variants, myopericytoma including myofibroma, and angioleiomyoma.

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The renal pericytic tumor is extremely rare, and only few comprehensive discussions about this entity have been done.

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We report the first documented case of renal pericytic tumor in a 58-year-old Korean male.

Introduction

A pericytic tumor is a group of mesenchymal neoplasm found in superficial tissues and only rarely described in viscera. The family of pericytic tumors includes glomus tumors and variants, myopericytoma including myofibroma, and angioleiomyoma etc. The renal pericytic tumor is extremely rare, and only few comprehensive discussions about this entity have been done.

Presentation of case

A 58-year-old man was transferred to our institute with suspicions of renal cell carcinoma. The kidney dynamic computed tomography scan showed a 3 cm sized solid mass in the upper pole of the right kidney. Laparoscopic radical nephrectomy was performed due to the deep-seated mass. Pathological result confirmed that the kidney mass was renal pericytic tumor.

Discussion

Although general biological behavior of published renal pericytic tumors is likely to be benign, the clinicopathologic experiences are very limited. Therefore, we should evaluate the malignant potential of the entity according to the parameters proposed for soft tissue tumors, including tumor location, tumor size, growth pattern, cellularity, cytological atypia, and mitotic figures with atypical forms. The current case shows several worrisome features, including an extremely rare tumor location, partially infiltrative growth, and a mildly increased proliferating index, which resulted in it being classified as an uncertain malignant potential.

Conclusion

We described the first case of renal pericytic tumor, addressing uncertain malignant potential, in a Korean male, which would be a distinct mesenchymal neoplasm differentiating from other groups of perivascular tumor families based on histological and immunohistochemical features.

Mesenchymal Neoplasms of the Genitourinary System: A Selected Review with Recent Advances in Clinical, Diagnostic, and Molecular Findings

Mesenchymal neoplasms of the genitourinary (GU) tract often pose considerable diagnostic challenges due to their wide morphologic spectrum, relative rarity, and unexpected incidence at GU sites. Soft tissue tumors arise throughout the GU tract, whether from adventitia surrounding or connective tissues within the kidneys, urinary bladder, and male and female genital organs. This selected article focuses on a subset of these lesions, ranging from benign to malignant and encompassing a range of patterns of mesenchymal differentiation, where recent scholarship has lent greater insight into their clinical, molecular, or diagnostic features.

[Renal angioleiomyoma with a myogenic and melanocytic immunophenotype, as a variant of angiomyolipoma]

We present a case of a 67 year old male with a cortical nodular tumour of the left kidney. During a year's follow-up with ultrasound and MRI, the tumour was seen to increase in size by 16-20 mm. The nodule was surgically removed. Microscopically it was well defined and unencapsulated, with a proliferation of typical fusiform cells of smooth muscle cell appearance, clumped around well vascularized areas. Immunohistochemically, the neoplasm was positive for muscle markers (smooth muscle actin, desmin and caldesmon) and melanocyte markers (HMB-45 and Melan A). Our case would appear to be a renal neoplasm with an angioleiomyomatous pattern, but with immunohistochemical characteristics of angiomyolipoma (PEComa), however, without either a lipomatous or lipid cell component. We found no previous reports of this type of tumour in the literature.

Myopericytoma/myopericytomatosis of the lower extremity in two young patients: a recently designated rare soft tissue neoplasm

Myopericytomas are rare, slow-growing benign perivascular tumors most commonly arising within the superficial subcutaneous soft tissues of the lower extremity. They represent one of several related perivascular tumors of myoid lineage with similar morphology and shared immunohistochemical profile including positive staining for smooth muscle actin. Histologically, myopericytoma exhibit concentric, perivascular proliferation of spindled myoid cells with bland elongated nuclei and associated blood vessels. A solitary well-demarcated nodule or mass is typically referred to as myopericytoma, whereas an infiltrative multinodular lesion has more recently been termed myopericytomatosis. At magnetic resonance imaging, tumors are most commonly superficial, may be well-defined (myopericytoma) or ill-defined (myopericytomatosis), and demonstrate highly vascularized, avidly enhancing soft tissue often with areas of internal hemorrhage. We report 2 cases involving the lower extremity (1 myopericytoma and 1 myopericytomatosis) occurring in young patients, focusing on the clinical, histopathologic, and radiologic characteristics of this relatively new distinct entity.

Foot soft tissue myopericytoma: Case-report and review

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Myopericytoma is a rare tumor of deep soft tissues.

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Small tumefying at the level of the plantar region, between the 2nd and 3rd toe of the right foot.

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Neoformation of 0.6 cm in diameter, well circumscribed, capsulated and with free resection margins.

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The immunohistochemical profile was consistent for positive alpha-actin and negative desmine.

Introduction

Myopericytoma is a rare tumor of deep soft tissues, originating from pericytes and characterized by numerous thin walled blood vessels.

Case report

We report a case of myopericytoma found at the level of the second toe of the right foot.

A patient came to the Endocrinology Surgery Department of Catania Polyclinic because of a presence of a small swelling in the plantar region, between the 2nd and 3rd toe of the right foot. At the anatomopathological examination, the escalated lesion showed a neoformation of 0.6 cm in diameter, well circumscribed, capsulated, with myopericytoma diagnosis.

Discussion

Its histopathological appearance is similar to myofibromatic lesions from glomic and angiomyoma tumors. It is a rare tumor that affects all ages with a peak after 50 years 3. The most frequent localization is at the lower extremities, particularly in soft subcutaneous tissues, but can rarely occur in other sites.

Conclusion

At the anatomopathological evaluation, the immunohistochemical examination for the correct formulation of the diagnosis is essential and an adequate surgical excision is important.

Glomangioma of the Kidney: A Rare Case of Glomus Tumor and Review of the Literature

Background

Glomus tumors are rare mesenchymal tumors originating from glomus bodies in the skin. Glomus tumors of the kidney are rare tumors and only a few cases have been reported in the medical literature. An extensive search revealed a very limited number of primary renal glomus tumors. Although most of these cases were benign in nature, including a case with uncertain diagnosis of malignant potential, two were malignant.

Case Report

We present a unique case of a 57-year-old male patient with an incidentally discovered 2 cm left renal mass. Histopathology examination and immunohistochemical studies confirm the diagnosis of glomangioma (a form of glomus tumor). The patient was followed for one year after partial nephrectomy and showed a benign course without any evidence of local recurrence or metastasis.

Conclusion

To the best of our knowledge, this is the 16th case of primary benign renal glomus tumors. Primary renal glomus tumors are rare and may mimic other mesenchymal renal neoplasms radiologically. Proper investigation (including histopathological analysis and immunohistochemical staining) of kidney tumors is essential to make the diagnosis of glomus tumors, which usually show a benign clinical course following resection.

Case Report: A giant myopericytoma involving the occipital region of the scalp - a rare entity

Herein we report a rare case of a giant myopericytoma presenting in a 16-year-old girl as a slowly progressive swelling involving the scalp in the occipital region. It was managed by complete excision. Histological examination of the lesion revealed  spindle-shaped cells forming characteristic rosettes around the blood vessels, and positive staining with smooth muscle actin.

Myopericytoma in urinary bladder: a case report

BACKGROUND

Myopericytoma is reported to occur mainly in the skin and superficial soft tissue of the extremities. In contrast, occurrence in the urinary bladder is extremely rare.

CASE PRESENTATION

We describe a 75-year-old Japanese man who developed a submucosal tumor at the right trigone of his bladder that led to interference with the discharge of right ureteral calculus. No invasive growth was observed by magnetic resonance imaging. Transurethral resection was successfully performed; histopathological analysis revealed perivascular proliferation of spindle-shaped to oval-shaped, cytologically bland tumor cells with eosinophilic cytoplasm. On immunohistochemical examination, the tumor cells were positive for alpha-smooth muscle actin, desmin, CD34 and h-caldesmon.

CONCLUSION

Cystoscopic and pathological findings were compatible with a diagnosis of myopericytoma of the urinary bladder.

Benign perivascular myoid cell tumor (myopericytoma) of the urinary tract: a report of 2 cases with an emphasis on differential diagnosis

Myopericytoma is a benign mesenchymal neoplasm thought to comprise part of a spectrum of perivascular myoid cell neoplasms with myofibroma, angioleiomyoma, and glomus tumor. We describe 2 such neoplasms involving the urinary tract: 1 incidentally identified in the kidney of a 59-year-old woman and 1 in the urinary bladder of a 52-year-old woman who presented with urinary frequency and dysuria. Histologically, the bladder tumor was composed of numerous blood vessels surrounded by plump perivascular myoid cells, as in subcutaneous myopericytoma. The renal tumor showed similar morphology centrally and a symplastic glomus tumor-like growth pattern at the periphery. Immunohistochemically, both tumors were reactive for markers of smooth muscle differentiation, such as smooth muscle actin and caldesmon/calponin but negative for CD34, cathepsin K, and S100 protein. Both patients are free of disease 14 and 39 months after resection, respectively. Our findings broaden the morphologic spectrum of myopericytoma.

Renal myopericytoma: A case report with a literature review

Myopericytoma is a rare neoplasm that generally arises from the skin and superficial soft tissues of distal extremities, and is particularly rare in the visceral organs. The current report presents a case of giant myopericytoma showing kidney involvement, which is extremely rare. A 39-year-old male presented to the Department of Urology with a 2-month history of a painless and palpable mass in the region of the left abdomen. Unenhanced computed tomography revealed a 9×10×18-cm³ mass that was heterogeneous with central lower density. The patient underwent radical nephrectomy, including lymphadenectomy, without adjuvant therapy. The tumor was composed of spindle-shaped myoid cells with a concentric arrangement and showed immunoreactivity for smooth muscle actin and cluster of differentiation (CD)10, and had a Ki-67 index of <1%; however, staining was negative for CD34, desmin, S-100 protein, cytokeratin, human melanoma black (HMB)-45, B-cell lymphoma (Bcl)-2 and CD99. Routine follow-up revealed no local or distant metastatic signs of reccurrence for 20 months. The present report shows that renal myopericytoma may be a benign tumor, and surgical excision without adjuvant therapy may be the only potentially curative treatment approach.

Myopericytoma of the external auditory canal and tragus

Background:

Myopericytoma is a relatively recently described skin and soft tissue tumour that demonstrates perivascular myoid cell or pericytic differentiation. Whilst the range of anatomical locations has expanded to include visceral locations, head and neck myopericytomas are rarely documented. There have been no previous reports of aural myopericytoma.

Case report:

This paper reports the clinicopathological features of a biopsy-proven, slow-growing, 20 × 20 mm, polypoid myopericytoma that involved the external auditory canal and tragus in an 18-year-old woman. Excision was curative.

Conclusion:

Heightened clinicopathological awareness of the expanding anatomical distribution of myopericytoma is critical to its diagnosis when it presents in unusual and novel locations. Myopericytoma should be added to the range of external auditory canal neoplasms, especially those characterised by an admixture of spindle cells and a prominence of blood vessels, including those with a haemangiopericytomatous pattern.

Renal Myopericytoma: Case Report and Review of Literature

Myopericytoma arising in the visceral organs is rare and only 1 case of renal myopericytoma has been reported in the literature to date. We report the second case of myopericytoma arising in the kidney in a 40-year-old Hispanic woman who presented with pain on the left side of the abdomen and frequent urination. Abdominal computed tomography scan showed an exophytic left-sided renal mass. Partial nephrectomy was performed. The patient remains free of disease at 24 months after diagnosis. Our case is histologically distinct from the previously described case as it lacks the “hemangiopericytic/glomangiopericytoma” pattern. The tumor in our case showed the characteristic pattern of myopericytoma and an additional glomus tumorlike pattern. The tumor cells showed diffuse reactivity for vimentin, smooth muscle actin, smooth muscle myosin heavy chain, and muscle-specific actin in both morphologic patterns and strong diffuse CD34 expression in glomus tumorlike focus. This case report adds to the morphologic heterogeneity of myopericytomas.

Multiple myopericytoma of the face and parotid gland

Myopericytoma is a benign tumor that is composed of myoid-appearing oval to spindle-shaped cells with a concentric perivascular pattern of growth. The tumor is morphologically heterogeneous and can exhibit a broad histologic spectrum. We describe a case of multiple myopericytoma occurring in the head and neck skin region with involvement of the parotid gland where it is known to occur very rarely. A 40-year-old woman noticed multiple enlarging, painless, round-shaped masses on her left cheek. The patient had experienced a similar lesion of the same area 8 years earlier which was completely excised and the pathological diagnosis was spindle cell type myoepithelioma. On a computed tomographic image, one mass involved the superficial parotid gland and was well encapsulated. Excision of the facial masses and superficial parotidectomy with facial nerve preservation were performed. A diagnosis of myopericytoma was established in light of the immunohistochemical pattern with the histopathological findings. Over the 4-year follow-up period, there was no evidence of recurrence. As many perivascular myoid neoplasms share common morphologic features with myopericytoma, we should consider the differential diagnosis, and confirm the histological findings with appropriate immunohistochemical staining. After identifying myopericytoma, it should be treated with wide surgical excision to prevent local recurrence.

Myopericytoma and arterial intimal thickening: the relationship between myopericytes and myointimal cells

BACKGROUND

Myopericytomas with intravascular growth have been reported and have been occasionally documented as intraarterial. In a retrospective study, we assessed intraarterial growth in myopericytomas, co-existence with arterial intimal thickening (IT) and the relationship between the two.

METHODS

This retrospective study was undertaken using 11 myopericytomas evaluated in serial microscopical sections. The results in light microscopy, electron microscopy and immunohistochemistry [including α-smooth muscle actin (SMA), desmin and h-caldesmon] were evaluated.

RESULTS

In four myopericytomas, we found intraarterial growth, with large areas of disrupted arterial wall and attachment of veins and venules, exhibiting angiogenic phenomena. Arterial IT was present and partially incorporated within the tumor (simulating medium-sized vessels). The neointimal (myointimal) cells shared morphological and immunohistochemical phenotype with the myopericytoma myoid cells, including α-SMA positivity and desmin negativity. Four of the remaining myopericytomas showed structures similar to arterial IT within the tumor.

CONCLUSIONS

The findings shown here, including the association between myopericytomas and arterial IT, the incorporation of the latter into the tumor and the similar phenotype of their respective myoid and myointimal cells, support a close relationship between these processes. Histogenically, the pericytes of the penetrating neovasculature originating from the attached venules and veins may contribute to both lesions.