myofibroma

Myofibroma: A Rare Pediatric Tumor

Myofibroma, also known as myobroma, is a rare type of tumor that primarily affects children and infants. It can occur in one area or multiple sites, making it a complex condition to diagnose and treat.

Characteristics

• Myofibromas are characterized by the presence of nodules of spindle cells that resemble smooth muscle cells.
• These tumors contain less differentiated cells that are small, round, and basophilic.
• They can be benign or malignant, although the latter is rare.

Types of Myofibroma

• Solitary Infantile Myofibroma: This type occurs in the first two years of life and is typically a solitary lesion.
• Myofibromatosis: This condition involves multiple myofibromas that can occur in various parts of the body, including the skin, bone, muscle, and visceral organs.

Histological Description

• Myofibroma is characterized by a biphasic growth pattern of immature-appearing, plump spindled tumor cells associated with numerous thin-walled, branching solitary fibrous tumor-like vessels.
• The background is represented by a collagenous stroma.

Clinical Presentation

• Myofibromas can present as firm nodules in the skin, subcutaneous tissue, or soft tissues.
• They can be painful and may cause discomfort to the affected individual.

Differential Diagnosis

• Myofibroma must be differentiated from other conditions such as nodular fasciitis, infantile fibromatosis, or inflammatory myofibroblastic tumor.

Prognosis

• The prognosis for myofibroma depends on the location and extent of the tumor.
• Solitary myofibromas have a good prognosis with spontaneous regression or cure with resection.
• Multicentric or generalized myofibromatosis can be more aggressive and may require more extensive treatment.

References

• [1] Myofibroma is a rare, abnormal growth occurring in the head and neck of primarily infants and children. (Source: #9)
• [2-5] Myofibromas are characterized by the presence of nodules of spindle cells that resemble smooth muscle cells. (Sources: #1-#5)
• [6-8] Myofibroma can occur as a solitary nodule or multicentric nodules, with varying degrees of cellular differentiation. (Sources: #6-#8)
• [9-15] The prognosis for myofibroma depends on the location and extent of the tumor. (Sources: #9-#15)

Myofibroma, also known as infantile myofibromatosis (IM), is a rare disorder characterized by the growth of one or more noncancerous (benign) tumors affecting the skin, bone, muscle, soft tissues, and organs. The signs and symptoms of myofibroma can vary depending on the location and number of lesions.

Common Symptoms:

• Skin Lesions: Firm-rubbery, flesh-colored to purple tumors or subcutaneous masses underlying normal skin [8]
• Subcutaneous Masses: Tumors affecting the tissues below the skin, which may be firm or rubbery in texture
• Painless and Slow-Growing Masses: Patients with myofibroma typically present with a painless, slow-growing mass that can affect various parts of the body [14]

Specific Symptoms:

• Cutaneous Myofibromas: May present as purplish macules, resembling a vascular neoplasm [4]
• Visceral Lesions: Can cause symptoms related to the distribution of these tumors and may lead to complications in organs such as the abdomen, pelvis, lungs, or retroperitoneum [9]

Demographics:

• Age Range: Typically affects males in early childhood or adulthood, with a reported predisposition for the head and neck region [12]
• Sex: Males are more commonly affected than females

It's essential to note that myofibroma can be asymptomatic, and some patients may not exhibit any symptoms at all. However, when present, these symptoms can vary in severity and may require medical attention.

References:

[4] - Context result 4 [8] - Context result 8 [9] - Context result 9 [12] - Context result 12 [14] - Context result 14

Myofibromas can be challenging to diagnose, but various diagnostic tests can help confirm the presence of this condition.

Imaging Studies

• Ultrasound is often used as a first-line imaging modality to identify myofibromas. These tumors typically appear as masses with an anechoic center [2].
• Magnetic Resonance Imaging (MRI) can also be used to evaluate myofibromas, showing low signal intensity on T1-weighted images and high or low signal intensity areas on T2-weighted images [2].

Molecular Genetic Testing

• DNA testing from a blood sample can confirm the diagnosis of infantile myofibromatosis by identifying specific genetic mutations [3].
• Molecular genetic testing can aid in the diagnosis of myofibroma, especially when histomorphological and immunohistochemical features are unusual [7].

Histopathology

• A biopsy of an accessible lesion (usually skin) should be performed to confirm the diagnosis. Histopathology shows a well-circumscribed tumor with characteristic spindle cell morphology [8].
• The diagnosis can also be established after complete excision of the lesion and histopathological examination, as seen in some case studies [11].

Blood Tests

• Blood tests may show mild neutrophilia and lymphopenia, but normal hemoglobin, white cell, and platelet counts. Elevated LDH levels (501 IU/L) have also been reported in some cases [5].

These diagnostic tests can help confirm the presence of myofibroma, although a definitive diagnosis often requires histopathological examination.

References: [2] - Search result 2 [3] - Search result 3 [5] - Search result 5 [7] - Search result 7 [8] - Search result 8 [11] - Search result 11

Treatment Options for Myofibroma

Myofibroma, a rare fibroblastic-myofibroblastic tumor in children, can be challenging to treat due to its unpredictable biological behavior. While spontaneous regressions have been reported, some cases may require medical intervention.

• Surgical Management: In most cases, myofibromas are managed surgically, with the goal of removing the tumor completely.
• Chemotherapy: For more aggressive disease or multifocal lesions, chemotherapy may be used as a treatment option. Low-dose weekly methotrexate and vinblastine have been shown to be effective in some cases [6][8].
• Targeted Therapy: Sorafenib and imatinib have been used to treat generalized myofibromas, with continued tyrosine kinase inhibitor therapy helping to maintain remission [2].
• Spontaneous Regression: In many cases, myofibromas may regress spontaneously without the need for treatment.

Important Considerations

• Treatment depends on the location and severity of the lesions.
• Recurrence of lesions has been reported in some cases.
• Standard therapy is low-dose weekly methotrexate and vinblastine, indicated for multifocal progressive life-threatening lesions [5].

It's essential to consult with a medical professional for personalized advice on treating myofibroma.

References:

[1] - Not available (no relevant information found) [2] Context 2 [3] Context 3 [4] Context 4 [5] Context 5 [6] Context 6 [7] Context 7 [8] Context 8

Differential Diagnosis of Myofibroma

Myofibroma, also known as infantile myofibromatosis, is a rare disorder characterized by the growth of one or more noncancerous (benign) tumors affecting the skin, bone, muscle, soft tissue, and other areas. The differential diagnosis of myofibroma is extensive and includes various conditions that may present with similar clinical and histopathological features.

Conditions to Consider in Differential Diagnosis

• Myopericytoma: This tumor shares significant overlap with myofibroma and may fall along a spectrum. A concentric perivascular proliferation favors myopericytoma, whereas a biphasic appearance with hyalinized paucicellular areas favors myofibroma [1].
• Central Hemangioma and Aneurysmal Bone Cyst: These conditions should be considered in the differential diagnosis of multilocular myofibromas.
• Nerve Sheath Tumor, Neurofibroma, Schwannoma, Malignant Peripheral Nerve Sheath Tumor, Intramuscular Myxoma, and Synovial Sarcoma: These tumors should be considered in the differential diagnosis of solitary myofibromas.
• Hemangioma, Lymphangioma, Neurofibroma, Infantile Fibrosarcoma, Langerhans Cell Histiocytosis, and other neoplasms: These conditions should be included in the differential diagnosis of solitary lesions.
• Nodular Fasciitis, Neurofibroma, Fibrous Histiocytoma, Cutaneous Inflammatory Pseudotumors, Dermatomyofibromas: These conditions should be considered in the differential diagnosis of myofibroma.

Key Features to Consider

• Histopathological features, such as concentric perivascular proliferation and biphasic appearance with hyalinized paucicellular areas.
• Immunohistochemical profile, including negative vascular, neural, and histiocytic markers CD34, S100, and CD68.
• Clinical presentation, including age of onset, location, and size of the tumor.

Conclusion

The differential diagnosis of myofibroma is complex and requires careful consideration of various conditions that may present with similar clinical and histopathological features. A thorough evaluation of histopathological features, immunohistochemical profile, and clinical presentation is essential to arrive at a final conclusive diagnosis.

References:

[1] Myopericytoma: A distinctive perivascular myoid neoplasm. [2] Infantile myofibroma (IM) or myofibromatosis: A common fibromatosis of infancy and childhood.