Myopericytoma of the Right Middle Finger: A Case Report of an Uncommon Perivascular Neoplasm.

This report describes the case of a 29-year-old male who presented with painless swelling on the volar aspect of his right middle finger. The initial clinical impression was consistent with an epidermal inclusion cyst. A plain radiograph of the lesion revealed a circumscribed superficial nodular soft tissue mass confined to the dermis of the affected finger. Following surgical excision and subsequent histopathologic examination, the lesion was ultimately identified as a myopericytoma (MPC). The occurrence of MPCs in the finger is uncommon; thus, a high level of suspicion is required to consider it as one of the differential diagnoses for painless nodules in this anatomical location. Surgery serves as the primary method for treatment, and histopathologic evaluation plays a crucial role in confirming the diagnosis and ruling out malignancy.

Malignant myopericytoma originating from the colon: A case report.

BACKGROUND: Myopericytoma is a benign tumor that typically occurs within subcutaneous tissue and most often involves the distal extremities, followed by the proximal extremities, neck, thoracic vertebrae and oral cavity. Complete resection is often curative. Malignant myopericytoma is extremely rare and has a poor prognosis. Here, we report for the first time a case of malignant myopericytoma originating from the colon. CASE SUMMARY: A 69-year-old male was admitted to our hospital with right upper quadrant pain for five days. Imaging suggested a liver mass with hemorrhage. A malignant hepatic tumor was the initial diagnosis. Surgical resection was performed after a complete preoperative work up. Initial postoperative pathology suggested that the mass was a malignant myoblastoma unrelated to the liver. Four months after the first surgery, an enhanced computed tomography (CT) scan revealed a recurrence of the tumor. The diagnosis of malignant myopericytoma derived from the colon was confirmed on histopathological examination of the specimen from the second surgery. The patient did not return to the hospital regularly for surveillance. The first postoperative abdominal CT examination six months after the second surgery demonstrated multiple liver metastases. Survival time between the diagnosis of the tumor to death was approximately one year. CONCLUSION: Malignant myopericytoma is a rare cancer. Preoperative diagnosis may be difficult. Due to a lack of treatment options, prognosis is poor.

Myopericytoma/myofibroma as a stromal component of mixed epithelial and stromal tumor of the kidney: A case report.

Mixed epithelial and stromal tumors (MESTs) of the kidney are rare renal neoplasms, primarily affecting middle-aged women. These tumors are characterized by a mix of epithelial and stromal components. While generally benign, MESTs require accurate diagnosis and appropriate management due to the potential for malignant transformation. The present study reports the case of a 75-year-old male patient who underwent a partial nephrectomy following the incidental discovery of a kidney tumor. Histopathological examination revealed a partially cystic tumor with solid areas, measuring 26 mm in diameter. The tumor had cysts lined with cuboidal cells and an ovarian-like stroma. The solid component consisted of elongated cells with eosinophilic cytoplasm and oval nuclei, showing angiocentric growth around small blood vessels without nuclear atypia or mitoses. Since the morphology of the solid component could not reveal the differentiation of those cells, immunohistochemical staining was performed and a myopericytoma/myofibroma component was established, mostly based on the positivity of smooth muscle actin, muscle-specific actin, h-caldesmon, estrogen receptor, progesterone receptor, solute carrier family 2 facilitated glucose transporter member 1 and collagen IV, along with a lack of staining for desmin, CD34, CD31 and CD99. Thus, to the best of our knowledge, for the first time in the literature, MEST with myopericytoma/myofibroma stromal component in a male patient was reported.

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.

Pericytic Lesions: A Paradigm of Overlapping Features.

Although myopericytoma and glomangiopericytoma are considered the subtypes of the group myopericytomas (MPC), they differ morphologically. Both of the tumors arise from pericytic cells. Scalp MPC are infrequent, but extranasal glomangiopericytomas are extremely rare. Herein, we report a case of a 36-year-old female presenting with slowly growing scalp swelling. Histopathology showed a dermal tumor with features of myopericytoma as well as glomangiopericytoma within the same lesion. Immunohistochemistry and reticulin staining confirmed pericytic origin but could not differentiate between the two tumors. This case report adds to the rarity and morphologic heterogeneity of the group MPC.

Pediatric upper lip myopericytoma: a case report and comprehensive review.

BACKGROUND: Myopericytoma is a rare spindle cell tumor of mesenchymal origin, typically benign, characterized by concentric proliferation of tumor cells around blood vessels within subcutaneous tissue. It primarily occurs in middle-aged adults and is often located in distal extremities, although cases have been reported in proximal extremities and head-neck regions. However, occurrences within the oral cavity are exceedingly rare. To date, literature reviews have identified only two cases in children under 10 years old and reported only five cases of myopericytoma occurring in the lip region. We provide a comprehensive review and analysis of all documented cases to better understand this condition. CASE PRESENTATION: A 7-year-old girl presented to oral and maxillofacial surgery with the discovery of a painless mass on the inner aspect of the upper lip. The diagnosis of myopericytoma was confirmed by histological examination (HE staining), alcian blue staining, and immunohistochemistry. CONCLUSIONS: Following surgical excision, there were no signs of recurrence at a 3-month follow-up. The pathological diagnosis of myopericytoma is quite challenging, and immunohistochemical testing is necessary.

Myopericytoma in an Infant-Imaging Characteristics of a Rare but Benign Entity.

Teaching point: Myopericytoma is a rare soft tissue tumor but should be considered in the differential diagnosis of infants with a fast-growing perivascular tumor.

Myopericytoma of the patella with local recurrence and patellectomy: A case report.

INTRODUCTION AND IMPORTANCE: Myopericytomas are tumors originating from perivascular myoid cells and exhibiting a wide range of histologic growth patterns. They rarely occur in bones, and no case of myopericytoma in the patella has been reported so far. CASE PRESENTATION: A 74-year-old male presented with a chief complaint of pain in the left knee. Magnetic resonance imaging revealed bone tumor and osteolytic lesions of the patella. The patient underwent bone tumor curettage and filling of the cavity with artificial bone. However, as the tumor reoccurred, a patellectomy was performed. The patient regained premorbid functional status after surgery. Additionally, there was no radiological evidence of recurrence of the lesion 3 years after patellectomy. CLINICAL DISCUSSION: Myopericytoma of the patella is very rare. However, it should be considered for the differential diagnosis of lytic lesions of the bone. Although surgery is curative, patellectomy may be necessary for recurrent cases. CONCLUSION: In conclusion, we report the first case of patellar myopericytoma. Although patellar myopericytoma might be rare, it should be considered for the differential diagnosis of lytic lesions of the bone. Surgery is curative; however, patellectomy may be necessary in recurrent cases.

Myopericytoma in the corpus cavernosum of the penis: A case report of a rare disease.

Introduction: Myopericytomas usually occur in the extremities of older individuals; however, they also rarely occur in the penis. We report a case of myopericytoma in the corpus cavernosum of the penis and review the relevant literature. Case presentation: A 76-year-old man presented with a slow-growing painless nodule on the left side of the penis. On physical examination, a non-tender, 7-mm mass was palpable. This tumor showed inhomogeneous low signal intensity on T2-weighted magnetic resonance imaging. The mass was excised and a myopericytoma diagnosed by pathological examination of the operative specimen. Conclusion: We here report a rare case of myopericytoma in the corpus cavernosum of the penis. To the best of our knowledge, this is the second reported case of a myopericytoma in the penis and the first in the corpus cavernosum of the penis. Clinicians should keep this rare possibility in mind when investigating a mass in the penis.

Gene fusions in superficial mesenchymal neoplasms: Emerging entities and useful diagnostic adjuncts.

Cutaneous mesenchymal neoplasms are diagnostically challenging because of their overlapping morphology, and, often, the limited tissue in skin biopsy specimens. Molecular and cytogenetic techniques have identified characteristic gene fusions in many of these tumor types, findings that have expanded our understanding of disease pathogenesis and motivated development of useful ancillary diagnostic tools. Here, we provide an update of new findings in tumor types that can occur in the skin and superficial subcutis, including dermatofibrosarcoma protuberans, benign fibrous histiocytoma, epithelioid fibrous histiocytoma, angiomatoid fibrous histiocytoma, glomus tumor, myopericytoma/myofibroma, non-neural granular cell tumor, CIC-rearranged sarcoma, hybrid schwannoma/perineurioma, and clear cell sarcoma. We also discuss recently described and emerging tumor types that can occur in superficial locations and that harbor gene fusions, including nested glomoid neoplasm with GLI1 alterations, clear cell tumor with melanocytic differentiation and ACTIN::MITF translocation, melanocytic tumor with CRTC1::TRIM11 fusion, EWSR1::SMAD3-rearranged fibroblastic tumor, PLAG1-rearranged fibroblastic tumor, and superficial ALK-rearranged myxoid spindle cell neoplasm. When possible, we discuss how fusion events mediate the pathogenesis of these tumor types, and we also discuss the related diagnostic and therapeutic implications of these events.

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.

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.

Myopericytomatosis: A rare entity mimicking other vascular tumours and malformations.

Myopericytoma is a rare tumour which typically presents as a benign lesion that mimics features of other more common vascular tumours and malformations. We present a case of a symptomatic diffuse myopericytomatosis of the left abdomen presenting as multiple subcutaneous vascular tumours detected on ultrasound and treated with ultrasound-guided sclerotherapy.

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.

Myopericytoma in the Antitragus of the Auricle: A Rare Tumor.

A myopericytoma in the auricle is rare. If an auricle contains a large, firm, red-brown mass, excision should be considered because the mass may be a myopericytoma. After excision, histopathological and immunohistochemical diagnoses are essential to rule out malignancy. Long-term follow-up is required because the tumor is slow-growing.

Expanding the Spectrum of Perioral Myogenic Tumors in Pediatric Patients: An SRF::NCOA2 Fused Perivascular Tumor of the Philtrum.

BACKGROUND: Perivascular tumors, which include myopericytoma and myofibroma, are rare benign soft tissue neoplasms composed of perivascular smooth muscle cells. Most demonstrate characteristic morphology and are readily diagnosed. However, a recently identified hypercellular subset shows atypical histologic features and harbor unique SRF gene fusions. These cellular perivascular tumors can mimic other more common sarcomas with myogenic differentiation. METHODS: Clinical, radiological, morphological, immunohistochemical, and molecular findings were reviewed. RESULTS: A slow-growing, fluctuant mass was noted within the philtrum at 16 months. Ultrasonography revealed a well-circumscribed cystic hypoechoic lesion. A small (1.0 cm), tan, well-circumscribed soft-tissue mass was excised after continued growth. Histologically, the encapsulated tumor was hypercellular and composed of spindle cells with predominantly-storiform architecture, focal perivascular condensation, dilated branching thin-walled vessels, increased mitoses, and a smooth muscle immunophenotype. An SRF::NCOA2 fusion was identified. CONCLUSION: We report the first case of an SRF-rearranged cellular myopericytoma in the perioral region in a young child. This case expands the differential diagnosis of perioral soft tissue tumors with myogenic differentiation. We highlight key clinical, pathological, and molecular features. As we illustrate, these rare tumors pose a considerable diagnostic challenge, and risk misdiagnosis as sarcoma, most notably spindle cell rhabdomyosarcoma.

Malignant myopericytoma: Case report and review of the literature.

A 29-year-old male presented with a two-week history of a tender lesion on his right thigh. The lesion was a 1.5 cm erythematous nodule with overlying hemorrhagic crust. Histopathologic examination of a biopsy specimen revealed a highly cellular neoplasm with irregular vesicular nuclei, prominent nucleoli, and scattered mitotic figures. The cells within the lesion were rounded, ovoid and spindle shaped cells with perivascular growth. The architecture and staining pattern of the lesion were most consistent with a diagnosis of malignant myopericytoma, an exceedingly rare malignancy.

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.

Intravascular Myopericytoma: A Case Report.

Myopericytoma is a rare tumor that arises from perivascular myoid cells. Intravascular myopericytoma is an exceptionally rare subtype with a small number of cases reported. Here, we describe the case of a 31-year-old woman who presented with a lump on the dorsum of the right foot for nine months. Imaging indicated that the lesion is in close proximity to the dorsalis pedis vessels. Following surgical excision, the histological analysis revealed a benign neoplasm arising within a vein wall with features of vascular and pericytic differentiation. When using immunohistochemistry, the blood vessels were highlighted by the cluster of differentiation (CD) 31 and smooth muscle actin (SMA) with negative staining for pancytokeratins. These features led to the diagnosis of intravascular myopericytoma.