Extra nuchal-type fibroma associated with elastosis, traumatic neuroma, a rare APC gene missense mutation, and a very rare MUTYH gene polymorphism: a case report and review of the literature*

Nuchal-type Fibroma Induced by Repetitive Trauma from Weightlifting: Case Report and Comprehensive Review of Literature

A nuchal-type fibroma (NTF) is a rare, benign, subcutaneous nodule that most frequently occurs in the posterior neck along the midline. It is characterized histologically by bundles of thick collagen fibers confined to the dermis and subcutaneous tissue of the posterior neck. Few trauma-related NTF cases have been published. We present a biopsy-proven case of NTF that is likely to have developed as a result of weightlifting activity in the gym, including repetitive trauma to the area of the lesion during the exercise known as the "barbell back squat." During this exercise, a heavy barbell was repeatedly rested on the patient's vertebral prominence at the level of C7/T1, the location where the NTF developed. Our 25-year old patient reported that he had been doing this exercise on a weekly basis for about 10 years. We believe that repetitive trauma at this location from specific weightlifting exercises may attribute to the incidence of NTF. A description of key magnetic resonance imaging characteristics and the surgical pathology of this case are provided, along with a review of current literature on trauma-related NTFs.

Nuchal-type Fibroma: Single-Center Experience and Systematic Literature Review

BACKGROUND

Nuchal-type fibroma is a rare benign tumor arising from the connective tissue. Our aim was to present our experience via two cases of this tumor and a comprehensive review of the literature.

PATIENTS AND METHODS

We report a case of a 23-year-old female with a mass located in the posterior neck and the upper back and a case of a 50-year-old male with a mass located in the posterior neck, which were proved to be nuchal-type fibromas in the histopathological examination. We also searched the PubMed/Medline database for published cases of nuchal-type fibromas.

RESULTS AND DISCUSSION

Nuchal-type fibroma is a rare benign tumor arising from the connective tissue, usually in the posterior neck, which affects different ages, with most patients being male. It is a poorly circumscribed tumor consisting of hypocellular, thick, dense and haphazardly arranged collagen bundles with entrapped adipocytes, nerve fibers and muscle fascicles and a few scattered spindle cells, which are CD34 positive. Its excision is curative, and the recurrence risk is generally low. However, patients with Gardner's syndrome may experience recurrence more frequently.

CONCLUSION

Nuchal-type fibroma should be included in the differential diagnosis of subcutaneous, soft-tissue masses, especially when these involve the posterior neck.

Germline APC mutations in hepatoblastoma

BACKGROUND

Conflicting reports on the frequency of germline adenomatous polyposis coli (APC) gene mutations in patients with hepatoblastoma (HB) have called into question the clinical value of APC mutation testing on apparently sporadic HB.

METHODS

An Institutional Review Board approved retrospective review of clinical data collected from patients with HB who received APC testing at our institution was conducted. All HB patients seen at Cincinnati Children's Hospital Medical Center were eligible for testing. Potential genotype/phenotype correlations were assessed.

RESULTS

As of July 2015, 29 patients with HB had received constitutional APC testing. Four (14%) were found to have APC pathogenic truncations of the APC protein and in addition two (7%) had APC missense variants of unknown clinical significance. Two patients (7%) had family histories indicative of familial adenomatous polyposis (FAP). Response to chemotherapy tracked differently in APC pathogenic cases, with a slower imaging response despite an equivalent or slightly faster α-fetoprotein (AFP) response.

CONCLUSION

The prevalence of pathogenic APC variants in apparently sporadic HB may be higher than previously detected. Differences in time to imaging response, despite similar AFP response, may impact surgical planning. All patients with HB warrant germline APC mutation testing for underlying FAP.

Extra nuchal-type fibroma associated with repetitive blunt trauma during religious activities

Nuchal-type fibroma (NTF) is a rare, benign subcutaneous tumor that usually arises from the posterior neck. NTF is histologically characterised by dense collagen bundles and sparse fibroblasts. Only four trauma-related cases have been previously published. Herein, we present a case of extra NTF with histopathology, and six palanquin porters by using snowball sampling technique in ethnographic field research. A palanquin is a type of human-powered transport carried upon the shoulders mostly seen in religious processions. All individuals (mean age, 26.8 years) displayed similar shoulder masses measuring up to 12 cm in the greatest dimensions. They averaged approximately 8.1 years of palanquin-carrying work each. We believe that long-term, heavy shoulder weight bearing of palanquins in religious dance performances may attribute to the incidence of extra NTF. This study reviews all literature of trauma-associated NTF through PubMed database, and highlights the association between repetitive blunt trauma and the development of NTF.

Nuchal-type fibroma of the shoulder: A case report and review of the literature

Nuchal-type fibroma, initially described in 1988 by Enzinger and Weiss, is a rare clinical entity associated with distinct subcutaneous and dermal fibrous tissue proliferation. The etiology of nuchal-type fibroma largely remains to be elucidated. Typical characteristics of this entity include hypocellular, haphazardly arranged collagen with entrapped adipose tissue, paucity of elastin and entrapped small nerves, on which the pathological diagnosis is based. Magnetic resonance imaging (MRI) is the preferred imaging modality for the detection of nuchal-type fibroma, due to its superior soft tissue resolution and multi-planar capabilities. The present study presents the unique findings of a nuchal-type fibroma arising in the shoulder of a 48-year-old man. Distinct features of the nuchal-type fibroma in the present case included hyperintensity on T1- and T2-weighted MRI. Microscopic examination revealed marked mucoid tissue degeneration. To the best of our knowledge, this is the first case report of nuchal-type fibroma presenting with these distinct features. The present findings may therefore assist with the general and differential diagnosis of nuchal-type fibroma.

Desmoid tumor patients carry an elevated risk of familial adenomatous polyposis

BACKGROUND

The prevalence of desmoid tumors among patients with familial adenomatous polyposis (FAP) is at least 10%, and the prevalence of FAP among desmoid patients varies between 7.5-16%.

METHODS

Data included 106 desmoid patients identified from the database of the Department of Pathology, Helsinki University Hospital, years 2000-2012. We evaluated the risk of FAP among patients by using endoscopy and we identified individuals with attenuated FAP by APC gene mutation test. We compared sporadic desmoid patients' and FAP patients' clinical characteristics.

RESULTS

Ten of 106 patients already had FAP diagnosis before the desmoid. Eleven patients had had FAP screening already earlier due to desmoid and three of them were found to have FAP. Total of 52 patients participated into prospective screening of FAP. No new cases of FAP were found. The risk of FAP among desmoid tumor patients was 4.8%. In the FAP desmoid group, there were more males and patients were younger than in the sporadic group. Intra-abdominal desmoids were more common in the FAP group.

CONCLUSIONS

Patients with desmoid carry an elevated risk of FAP and therefore screening is indicated. Asymptomatic patients with desmoid situated in extra truncal region may not need to be screened.

Multiple nuchal-type fibromas on the scalp: a case report

Nuchal-type fibroma is a rare, benign, fibrous, tumor-like proliferation characterized by dense hypocellular bundles of collagen, with sparsely scattered fibroblasts, interspersed fat tissue, and entrapped nerve fibers. It usually develops in the posterior neck as a solitary, firm, poorly circumscribed, subcutaneous mass. Herein, we report about a 32-year-old man who presented with a 6-year history of multiple nodules on the scalp. Histopathological features were consistent with those of nuchal-type fibroma. The tumors were surgically excised.