Plexiform fibromyxoma of the small bowel: A case report

Abstract

BACKGROUNDPlexiform fibromyxoma is a rare, special type of mesenchymal tumor. The most common presenting symptoms are anemia, hematemesis, and hematochezia, without sex or age predilection. The reported cases have mainly occurred in the gastric antrum and pylorus region, with some cases in the duodenum.CASE SUMMARYWe report here a case of plexiform fibromyxoma in the upper segment of the jejunum, which was continuously followed up for 3 years after surgical removal. Plexiform fibromyxoma showed multinodular or plexiform growth. The cells in the tumor node were spindle-shaped but few in number and mitotic figures. Small blood vessels and mucous matrix were found among the tumor cells. Immunohistochemistry revealed that the plexiform fibromyxoma cells were positive for smooth muscle actin, focally positive for CD10, and negative for cytokeratin, CD117, DOG-1 (discovered on GIST-1) desmin, S-100, epithelial membrane antigen, and CD34. Ki-67 labeling index was < 5%. Plexiform fibromyxoma showed benign biological behavior. After 3 years of consecutive postoperative follow-up, no obvious signs of metastasis or recurrence were found by imaging examination.CONCLUSIONPlexiform fibromyxoma is a rare type of mesenchymal tumor. The diagnosis mainly depends on pathological examination, and it should be distinguished from other gastrointestinal mesenchymal tumors.

An Update on Clinicopathological and Molecular Features of Plexiform Fibromyxoma

“…The typical presentation of PF is a nonspecific gastrointestinal complaint, such as abdominal pain, abdominal distension, and abdominal discomfort. Hemorrhagic gastrointestinal presentations are also commonly seen, with consequent GI bleeding-associated presentations like anemia, melena, and hematemesis [10, 36, 68, 74]. The available literature includes 121 cases, with clinical signs and symptoms available for 95 cases.…”

“…Many patients also presented with bleeding signs or symptoms, including anemia, melena, GI bleeding, and hematemesis. Severe hemorrhage leading to syncope [11, 53, 74] or hemodynamic instability [58] was also reported. Reflux symptoms might be present, with or without other complaints, and are likely to mask PF if presenting alone or with nonspecific complaints [22, 26, 68, 71, 80].…”

“…Microscopically, the tumor margin is infiltrative and unencapsulated; in 33 cases reporting the condition tumor margin, 20 were ill-defined and the rest were well-circumscribed. Necrosis was reported in the literature in only 2 cases: a 42-year-old female with fistulating abscess showed central necrosis as well as gas-fluids level [36], and a 31-year-old female with an ulcerative lesion exhibited only surface necrotic tissue coverage without central necrosis [74]. Some lymph nodes display enlargement with reactive changes [19, 67].…”

“…Partial immunoreactive or focally positive results with desmin, caldesmon, and CD10, consistent with a partial or incomplete muscle immunophenotype, suggest possible myofibroblastic differentiation. Ki-67 staining commonly illustrates very low proliferation rates, mostly <2%, indicating a very low grade/indolent mesenchymal tumor; nevertheless, 5% [44, 74], 6% [25], 30% [77], and a vascular endothelial Ki-67 index up to 40% [49] have also been reported.…”

“…Therefore, regardless of the operative technique, we suggest that complete resection still be the first consideration when treating PF rather than consideration of the conservativeness of the operative technique [30, 64, 71]. PF cases with severe clinical presentations, such as perforation [1, 21], infection [36], or considerable hemorrhage [53, 58, 63, 74], and with malignant suspicion, such as significant body weight loss [11, 72] or rapid tumor growth [16], should be addressed with aggressive radical surgical treatment rather than conservative management, despite the benign pathological results.…”