Solitary myofibroma of the sigmoid colon: case report and review of the literature

Abstract

A 58-year-old woman presented with a solitary myofibroma that arose in the sigmoid colon. Computed tomography revealed a highly enhanced intramural mass (1.3-cm maximum diameter) in the proximal sigmoid colon. Histologically, the tumor exhibited a biphasic growth pattern, which comprised haphazardly arranged, interwoven fascicles of plump, myoid-appearing spindle cells with elongated nuclei and abundant eosinophilic cytoplasm, and more cellular areas of primitive-appearing polygonal cells that were arranged in a hemangiopericytomatous pattern. The tumor cells were positive for smooth muscle actin (SMA), and negative for desmin, h-caldesmon, CD34, cytokeratin, S100 protein, and CD117. The Ki-67 labeling index was not high (up to 7%). Based on these histologic and immunohistochemical features, our patient was diagnosed with a myofibroma of the sigmoid colon. The presence of solitary myofibroma in the intestine of an adult requires attention to avoid misdiagnosis as a more aggressive mesenchymal tumor.Virtual SlidesThe virtual silde(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2096403796957687

Solitary Myofibroma of the Adult Mandible: A Case Report and Review of Literature

“…Mitoses are variable in number; especially in immature-appearing tumors, numerous mitoses as well as areas of necrosis may be present 4. Myofibroma should be differentiated from leiomyoma, neurofibroma, nodular fasciitis, hemangiopericytoma, and fibrosarcoma due to their macroscopic and microscopic similarites 2,6,10…”

“…Both forms were described as infantile myofibromatosis because of its multiplicity, typical age distribution (first decade of life), and frequent involvement of deep structures, including the central nervous system and visceral organs such as lung, heart, gastrointestinal tract, liver, kidney, and pancreas 1. In contrast to the multicentric form, solitary myofibroma usually presents as a cutaneous or subcutaneous mass of the head and neck region 2. Intraosseous lesions are much less common, although three studies in 1995 and one in 2000 reported the mandible as a frequent oral site (16 of 36 [or 44%],3 15 of 35 [or 42.6%],4 and 30 of 79 [or 38.0%]) 5.…”

Mesenteric Fibromyoma Mimicking a Colon Tumor: A Diagnostic Dilemma

“…They usually arise de novo and are seen in adults [6]. Myofibroma can occur as a solitary form or it can be seen as multiple lesions like generalized form which is described as myofibromatozis [2,7]. It is originally described as 'congenital generalized fibromyomatosis' in 1954 by Stout [2,8].…”

“…The most frequent tumors are Gastrointestinal Stromal Tumors (GIST) and smooth muscle tumors. GISTs as the largest group of these tumors are usually seen in the wall of gastrointestinal tract and 25% of them are malignant [2] . They usually occur in adults and there is no sexual predominance.…”

“…Fibromyoma is a benign mesenchymal tumor that can occur at visceral organs such as the heart, lung, liver, kidney, pancreas, gastrointestinal tract and central nervous system [2,3]. As well as smooth muscle tumors may mimic GISTs because of their large sizes, their behaviour is entirely based on their histological features by contrast with GISTs [2]. We present a huge intra-abdominal myoma clinically mimicking GIST.…”