Desmoid tumors, also referred to as aggressive fibromatosis, represent an uncommon form of fibroblastic proliferation. These neoplasms may arise within any musculoaponeurotic structure throughout the body. They are classified as benign due to several distinctive features: histologically, they exhibit regular mitotic activity and are devoid of metastatic potential. Computed tomography (CT) remains the definitive modality for precise diagnosis, and surgical excision is strongly advised. This account details the manifestation of a desmoid tumor located in the anterior abdominal wall of a 31-year-old female patient who notably lacks any prior surgical interventions. The surgical intervention entailed the excision of the neoplasm and subsequent reconstruction of the abdominal wall utilizing a polypropylene mesh. Postoperatively, the patient was released from the medical facility after a period of three days, having experienced no post-surgical complications. This was followed by a six-month interval free of any adverse events.

Most cases of desmoid-type fibromatosis (DTF) exhibit a mutation in APC or CTNNB1. We report a case of mesenteric DTF in which no mutation in APC or CTNNB1 was found, but a germline variant of uncertain significance (VUS) in RAD51C and a subclonal mutation in MYST3 were identified. Whether these genetic changes are important in DTF in this case, or whether genetically conventional DTF cells were present at a density below detection is unknown; it will be of interest to see results in further studies of wild-type APC/CTNNB1 cases.

BACKGROUND: Lipomatosis of nerve (LN) is a rare disorder characterized by the massive enlargement of peripheral nerves, frequently accompanied by generalized fibroadipose proliferation and skeletal overgrowth.
METHODS: The authors have been routinely following a 20-year-old male for lipomatosis of median nerve at the wrist noted shortly after birth. He had undergone resection of the lesion accompanied by sural nerve grafting at another institution. Clinically, although his neurological loss of function has been stable, he has had continued soft tissue growth. Serial magnetic resonance imaging has revealed persistent LN proximal to the repair sites with evidence of fatty proliferation in the sural grafts and continued LN and fatty proliferation distally. There has been a progressive circumferential pattern of fibrosis around the proximal and distal suture lines, which has a similar radiological pattern to desmoid type fibromatosis (a pattern recently described in neuromuscular choristoma [NMC] desmoid-type fibromatosis).
CONCLUSIONS: Considering the similar reaction of nerve in both LN and NMC despite differing genetic cascades, the authors believe a unifying process occurs in both lesions. The pattern of circumferential fibroproliferation would be most consistent with neuron-mediated growth from unspecified trophic factors, supporting a previously reported a nerve-derived \"inside-out mechanism.\" The clinical consequences of this unifying process are presented.

Mesenteric desmoid-type fibromatosis (DTF) is a rare benign yet aggressive neoplasm that has an unpredictable biological behavior ranging from spontaneous regression to extensive local infiltration and has a high tendency for recurrence. The presenting symptoms are usually nonspecific and mostly related to the large size of the tumor compressing adjacent organs. Imaging studies can be suggestive of the diagnosis, but confirmation is based on histopathological and immunohistochemical examination. The lack of knowledge on the etiology and pathogenetic behavior of this tumor leads to therapeutic and prognostic challenges. Future genetic studies may help in advancing our understanding of this neoplasm and in formulating the proper management and follow-up plan. Here we present a case of a 14-year-old female who presented to the emergency room complaining of diffuse abdominal pain and distention. A computed tomography (CT) scan showed a large mass occupying most of the abdominal cavity and compressing adjacent organs. Exploratory laparotomy with resection and anastomosis was performed, and the histopathological and immunohistochemical examination of the resected mass was consistent with mesenteric DTF.

Desmoid-type fibromatosis (DF) is a rare monoclonal, fibroblastic proliferation characterized by an unpredictable and variable clinical course. We present the case of a 56-year-old woman who underwent total thyroidectomy for papillary thyroid carcinoma in 2012 and who developed a cervical mass at the left laterocervical level during follow-up, raising the diagnosis of tumor recurrence. Computed tomography of the neck showed solid formations with heterogeneous contrast uptake in the right lateral region of the neck. At the level of the thoracic operculum, a second 26-mm formation was observed that medially contacted the left lateral wall of the trachea. Lateral lymphadenectomy was performed, which was incomplete. Histology showed findings consistent with desmoid-type fibromatosis. DF are slowly proliferating, non-metastatic tumors with a highly invasive capacity that are usually present in familial adenomatous polyposis (FAP)-Gardner syndrome. Our case had a history of massive colonic polyposis and first-degree relatives of colorectal cancer.
La fibromatosis de tipo desmoide (FD) es una rara proliferación fibroblástica monoclonal caracterizada por un curso clínico impredecible y variable. Presentamos el caso de una mujer de 56 años intervenida de tiroidectomía total por carcinoma papilar de tiroides en 2012 y que durante el seguimiento desarrolla una masa cervical a nivel laterocervical izquierdo, planteando el diagnóstico de recidiva tumoral. La tomografía computarizada de cuello demostró formaciones sólidas con captación heterogénea de contraste en la región lateral derecha del cuello. A nivel del opérculo torácico se observó una segunda formación de 26 mm que contactaba medialmente con la pared lateral izquierda de la tráquea. Se realizó una linfadenectomía lateral, que resultó incompleta. La histología mostró hallazgos compatibles con FD. La FD son tumores de proliferación lenta, no metastásicos y con una capacidad altamente invasiva que suelen estar presentes en la poliposis adenomatosa familiar (PAF)-síndrome de Gardner. Nuestro caso tenía antecedentes de poliposis colónica masiva y familiares de primer grado de cáncer colorrectal.

Desmoid-type fibromatosis (DF) is a rare subtype of soft tissue sarcomas that most commonly occurs in the anterior abdominal wall. When occurring in the retroperitoneum, DF is usually part of familial syndromes while only rarely sporadic. This makes it imperative to report any instance of experience with DF and the oncological outcomes of the different approaches to management. We report two cases of sporadic and severe DF occurring in the retroperitoneum at our institution.
UNASSIGNED: The first case is a male that presented with urinary obstruction symptoms and underwent surgical resection of the tumor that extended into the left kidney. The second case is a female with a history of recurrent desmoid tumors of the thigh and was incidentally diagnosed with retroperitoneal DF on imaging. She underwent tumor resection and radiotherapy; however, the tumor recurred with urinary obstruction symptoms that required another surgical resection. Histopathological characteristics and radiological imaging of both cases are described below.
UNASSIGNED: Desmoid tumors often recur, thus significantly influencing the quality of life which is reflected in one of our cases. Surgery remains a mainstay treatment, and both cases presented in this report required surgical resection of the tumors as symptomatic and curative measures.
UNASSIGNED: Retroperitoneal DF is a rare entity, and our cases add to the scarce literature available on the topic, which may well contribute to the formulation of practice-changing recommendations and guidelines focused on this rare variant of DF.

Retroperitoneal desmoid-type fibromatosis is a rare benign mesenchymal neoplasm that develops as a result of fibroblastic proliferation within the musculoaponeurotic stroma. The authors present the case of a 41-year-old male patient who was referred for a retroperitoneal neoplasm. A mesenteric mass core biopsy was done, and it revealed a low-grade spindle cell lesion consistent with desmoid fibromatosis.

Desmoid tumors are rare soft tissue tumors with slow growth and high recurrence rates. They typically arise sporadically in the abdominal wall or retroperitoneum, with a few rare cases reported after trauma and surgery. Postoperative desmoid tumors in adults are very rare with only 7 reported cases involving the paraspinal location. This is the first reported case of a male patient with a postoperative paraspinal desmoid tumor.

Mesenteric fibromatosis is a locally invasive myofibroblastic proliferation and rarely metastasize to other organs. Hollow organ perforation and acute diffuse peritonitis caused by mesenteric fibromatosis rarely occurred. Here we report a case of huge mesenteric fibromatosis who complained a paroxysmal epigastric pain, and CT scan showed a huge mass, pneumoperitoneum and ascites. An urgent laparotomy showed an intro-abdominal mass and perforation locating at the jejunum. Postoperative histology confirmed it to be mesenteric fibromatosis. With one-year follow-up, the patient had no recurrence. We wish to share our treating experience of this interesting case because it did not belong to a typical type but presenting with acute diffuse peritonitis, and total resection and R0 margin is a key to treat acute case. This atypical one has not been reported in the literature till now.

Desmoid tumors are rare, locally aggressive benign tumors with a high rate of recurrence even after complete resection. Only twenty percent are intrathoracic and they are often painless or minimally painful with slow growth. Rarely they can grow quite rapidly, mimicking a malignant tumor. Here we present a rare case of a rapidly growing, intrathoracic desmoid tumor mimicking lung malignancy in an elderly male ex-smoker. This case demonstrates the importance of including desmoid tumors in the differential diagnosis of lung masses, raising awareness of benign tumors mimicking malignant behavior, and emphasizing the potential benefit of timely follow-up and early diagnosis.