Nuchal-type fibroma in two related patients with Gardner's syndrome

Repetitive trauma-induced extra-nuchal-type fibroma

A nuchal-type fibroma is a rare, benign fibrous tumour that typically occurs in the posterior neck along the midline, but can occur in extra-nuchal locations, most commonly in the back, shoulder and face. We present a biopsy-proven case that arose as a result of heavy gym-related activities. In particular, a heavy barbell was rested on his vertebral prominence at the level of C7/T1 during leg squatting. Repetitive trauma as a cause for extra-nuchal-type fibromas has been sparsely reported, but we suggest that sustained high pressure is an additional required feature. Although this lesion was in the posterior neck, it was contained entirely within the subcutaneous tissues without involvement of the nuchal ligament. Hence, it was considered an extra-nuchal fibroma. A description of key ultrasound and MRI imaging characteristics are provided to assist in making the diagnosis, along with a review of the current literature and a discussion of differential diagnoses.

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.

Adipocyte-rich CTNNB1-mutated Intramuscular Gardner Fibroma Progressing to Desmoid Fibromatosis

Gardner fibroma (GF) is a benign soft-tissue tumor that is associated with Gardner syndrome and can progress to, or co-occur with, desmoid fibromatosis (DF). Herein, we report a unique case of an 11-year-old boy who presented with a rapidly growing soft-tissue mass after biopsy of a stable fat-rich lesion present in the calf muscles since infancy, with Magnetic resonance imaging findings suggesting an intramuscular adipocytic tumor. The resection showed GF and DF. DF arising from a preexisting GF (the so-called "GF-DF sequence") is a well-documented phenomenon. Although immunohistochemistry was negative for nuclear β-catenin expression, a CTTNB1 S45F mutation, which has been associated with aggressive behavior in DF, was identified in both components using a next-generation sequencing-based molecular assay. This is the first time a mutation in CTNNB1 has been identified in GF and the GF-DF sequence, thus expanding our knowledge of the molecular pathogenesis of the GF-DF sequence and highlighting the role of molecular testing in pediatric soft-tissue tumors. The histologic findings of an adipocyte-rich intramuscular GF also are unique, expanding the morphological spectrum of GF and adding GF to the differential diagnosis of intramuscular lesions with an adipocytic component.

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.

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.

Midline diastema and its aetiology--a review

Maxillary midline diastema is a common aesthetic complaint of patients. Treating the midline diastema is a matter of concern for practitioners, as many different aetiologies are reported to be associated with it. The appearance of midline diastema as part of the normal dental development makes it difficult for practitioners to decide whether to intervene or not at an early stage. The aim of this article is to review the possible aetiology and management options which will help the clinician to diagnose, intercept and to take effective action to correct the midline diastema. The available data shows that an early intervention is desirable in cases with large diastemas. Treatment modality, timing and retention protocol depends on the aetiology of the diastema. Therefore, priority needs to be given to diagnosing the aetiology before making any treatment decisions. Clinical Relevance: This article aims to determine and evaluate the aetiology and possible treatment options of midline diastema.

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*

We report a case of an extra nuchal-type fibroma in a 51-year-old male suspected to have attenuated familial adenomatous polyposis (Gardner's syndrome), who presented with a longstanding buttock mass excised due to enlargement and pain. Histopathologically, lobules of haphazard, hypocellular, hyalinized collagen bundles replaced the dermis and subcutis and entrapped nerve bundles, mimicking Morton neuroma. Ramifying nerve twigs found around larger nerve fascicles showed the co-existence of traumatic neuroma. Elastic tissue stain revealed elastosis characterized by large, arborizing fibers lying between and within the hyalinized collagen bundles. Modified Masson's trichrome stain showed light blue staining of collagen bundles producing the hyalinized nodules with irregular, light red staining of collagen bundles at their periphery and within tumor collagen. Compression and/or degeneration of collagen and secondary elastosis with later entrapment by tumor collagen could explain this microscopic phenotype. By immunohistochemistry, tumor spindle cells expressed nuclear β-catenin and cyclin D1, mostly within regions of fibrosis implicating activation of the adenomatous polyposis coli (APC)-Wnt pathway. Genetic analysis showed a missense mutation in APC gene (c.7504G>A, p.G2502S in exon 15) and a functional homozygous polymorphism in the MUTYH gene (c.36+325G>C, (IVS1+5G/C)). Nuchal-type fibroma has been associated with Gardner's syndrome and trauma. In this patient, genetic predisposition coupled with repetitive, localized trauma and collagen degeneration may have provided the stimulus for the development of extra nuchal-type fibroma.

Neonatal Gardner fibroma: a sentinel presentation of severe familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is a rare cause of colorectal cancer and rarely presents in early childhood. Various extracolonic manifestations, however, may be present before the development of overt polyposis. One of the rarest manifestations is the Gardner fibroma (GAF), which has particular histologic features. Here we report the case of a child who presented in the neonatal period with a paraspinal mass. Although the initial diagnosis was unclear, biopsy of a second lesion at 32 months of age, and a review of the first lesion, resulted in the diagnosis of GAF. After rectal bleeding at 47 months, colonoscopy revealed 75 to 100 colonic polyps. Adenomas were identified in multiple biopsies throughout the colon and from several polyps located in the duodenum. Polyps were visualized in the jejunum by wireless-capsule endoscopy. A total proctocolectomy was performed, and no malignant transformation was observed in the colon on pathologic inspection. A truncating mutation in APC (c.4479_4480delGG p.Glu1494LysfsX19) was identified in the child. Her parents and sister do not carry this mutation in lymphocyte DNA. To our knowledge, this is the first report of neonatal GAF as the presenting feature of a molecularly confirmed case of sporadic FAP and the earliest colonic and small bowel involvement reported of FAP. It illustrates the need to exclude FAP in a child who harbors fibromas suggestive of GAF, even in the absence of supportive evidence of FAP in the patient or relatives.

CD34-reactive tumors of the skin. An updated review of an ever-growing list of lesions

Over the past few years, a growing number of cutaneous tumors expressing CD34 is being reported. The list contains benign and malignant neoplasms as well as reactive and hamartomatous lesions of diverse lineages of differentiation, including fibroblastic, myofibroblastic, fibrohistiocytic, vascular, neural, adipocytic, smooth muscle, hematopoietic, melanocytic and epithelial. The more frequent diagnostic difficulties are found in spindle cell proliferations, mainly in those of the fibrocytic lineage. In part, this is because of the fact that in this area are, aside to well-defined entities, histologically and clinically diverse, recently reported cutaneous CD34-reactive lesions, whose definitions, limits and relationships are not completely established. The CD34 expression plays a key role in the differential diagnosis of some tumors, such as dermatofibrosarcoma protuberans, epithelioid sarcoma or pleomorphic hyalinizing angiectatic tumor of soft parts, with important therapeutic consequences. In others, as in desmoplastic trichilemmoma, it can help to resolve diagnostic problems in concrete cases. Finally, in many of the CD34-positive lesions, the diagnosis with the hematoxylin and eosin stain is straightforward. However, in all of them, the knowledge of the immunohistochemical profile contributes to our understanding of the cutaneous pathology.

Nuchal-type fibroma of the ankle: a case report

Nuchal-type fibroma is rare benign fibrous tumor that has the potential to recur. It is typically located in the subcutaneous tissues of the posterior aspect of the neck, although it can affect other anatomical sites. Extranuchal involvement occurs most commonly in the back, shoulder, and face, as well as other sites specified in single case reports. In this report, we describe the case of a patient presenting with a nuchal-type fibroma arising in the ankle. The lesion infiltrated the superior extensor retinaculum. Marginal resection was performed, and there was no evidence of recurrence after 12 months of follow-up. To our knowledge, this is the first report of a nuchal-type fibroma localized to the ankle.

Nuchal-type Fibroma of the Coccyx

Nuchal-type fibroma is a recently described, rare, tumor-like process of fibrous tissue occurring chiefly in the dorsocervical area. Nuchal-type fibromas in extranuchal locations are morphologically indistinguishable from lesions involving the nuchal region. Histopathologic findings of nuchal-type fibroma are poorly demarcated, dense collagen bundles with sparsely scattered fibroblasts, some interspersed adipose tissue, and entrapped nerve fibers. We report a patient with a mass on the coccyx area, and these were histopathologically consistent with nuchal-type fibroma. This tumor was surgically excised, and no recurrence had been noted during the two year follow-up period.

Application of immunohistochemistry to soft tissue neoplasms

CONTEXT

Soft tissue tumors are composed of numerous and complex diagnostic entities. Because of this complexity and the recognition of an intermediate malignancy category including some tumors with a deceptively bland histologic appearance, soft tissue tumors may represent a major diagnostic challenge to the general practicing pathologist.

OBJECTIVE

To correctly diagnose soft tissue tumors with the ancillary use of immunohistochemistry.

DATA SOURCES

Review of the current literature with emphasis on those tumors for which immunohistochemistry has proven to be particularly useful.

CONCLUSIONS

Immunohistochemistry plays an important role in the diagnosis of soft tissue tumors. One of its major utilities is to correctly identify a tumor as being of mesenchymal or nonmesenchymal origin. Once mesenchymal origin has been established, histologic subtyping according to specific cell lineage may be achieved with the use of lineage-specific markers. Tumors of uncertain cell lineage and tumors with primitive small round cell morphology are often characterized by a unique immunohistochemical phenotype. In this group of tumors, immunohistochemistry is most widely applied and is of greatest value. Despite the rapid development of molecular genetic techniques, immunohistochemistry still remains the most important diagnostic tool in the diagnosis of soft tissue tumors aside from recognition of morphologic features and clinical correlation.

Gardner Fibroma: A Clinicopathologic and Immunohistochemical Analysis of 45 Patients With 57 Fibromas

Gardner fibroma (GAF) is a benign soft tissue lesion with a predilection for childhood and adolescence and an association with familial adenomatous polyposis (FAP) and desmoid type fibromatosis (desmoid). We report 45 patients with GAF with clinicopathologic correlation and immunohistochemical analysis for beta-catenin and related proteins. Forty-five patients with 57 GAFs were identified from surgical pathology and consultation files. Immunohistochemistry for beta-catenin, cyclin-D1, and C-myc was performed on formalin-fixed, paraffin-embedded tissues using standard techniques in 25 GAFs from 24 patients. Information about family history, intestinal polyps, colon cancer, and soft tissue tumors was available in 23 patients. Sixty-nine percent had known FAP or adenomatous polyposis coli (APC), 22% had no history of familial polyps or soft tissue tumors, and 13% had an individual or family history of soft tissue masses and/or desmoids, with follow-up periods of 6 months to 26 years (median 3 y, mean 5 y). The age range at initial diagnosis was 2 months to 36 years. Seventy-eight percent were diagnosed in the first decade, 15% in the second decade, and 7% in the third decade. Eight patients (18%) had documented desmoids concurrently or later; 4 of these had FAP and 1 had familial desmoids. Sites of GAF included the back and paraspinal region in 61%, the head and neck in 14%, the extremities in 14%, and the chest and abdomen in 11%. All displayed a bland hypocellular proliferation of haphazardly arranged coarse collagen fibers with a bland hypocellular proliferation of inconspicuous spindle cells, small blood vessels, and a sparse mast cell infiltrate. Immunohistochemically, 64% showed nuclear reactivity for beta-catenin (9 patients with known APC, 5 without definite information about FAP). One hundred percent showed nuclear reactivity for both cyclin-D1 and C-myc. beta-catenin reactivity had no correlation with age, site, or recurrence. Two beta-catenin-negative GAFs were from FAP patients. In conclusion, GAF has a predilection for childhood and early adulthood, a strong association with FAP/APC, an association with concurrent or subsequent development of desmoids, and overexpression of beta-catenin and other proteins in the APC and Wnt pathways. The proportion of sporadic GAFs that have APC mutation remains to be determined.

Collagenosis Nuchae: a case report of a rare and often misdiagnosed condition

Enzinger and Weiss first described Collagenosis Nuchae (CN) or nuchal fibroma (NF) in 1988. CN is a rare benign soft tissue tumour that arises from the posterior cervical subcutaneous tissue with predilection for the interscapular and paraspinal regions. It is more common in males. CN has been reported in association with trauma, diabetes, scleredema and Gardner's syndrome. The true incidence of CN is probably higher than recognised and CN should be in the differential diagnosis of head and neck lesions. Histological examination is required for the diagnosis. Careful total excision provides cure and accurate diagnosis. The purpose of this study is to review the epidemiological, clinical, histopathological and radiological features of this rare lesion, which is often misdiagnosed.

Dermatofibrosarcoma protuberans association with nuchal-type fibroma

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a hypercellular, storiform, CD34-positive low-grade sarcoma with honeycomb entrapment of fat, which typically involves the trunk and extremities. Nuchal-type fibroma (NTF ) is a paucicellular, CD34-positive fibrous tumor with fat entrapment, which may occur in both nuchal and extranuchal locations and in association with Gardner syndrome.

METHODS

We report the association of DFSP with NTF in a 43-year-old male with no personal or family history of Gardner syndrome.

RESULTS

The patient had a past history of a DFSP removed from his back, which recurred 2 years later and was re-excised. Additionally, the patient had a typical NTF, in the posterior neck, removed at the same time. Histopathologic examination of the recurrent back lesion demonstrated a composite lesion with typical appearances of DFSP, centrally, blending into an NTF-like appearance, peripherally. Both components expressed CD34 and CD99, and lacked elastin. A review of the microscopic slides of the patient's previously excised DFSP revealed an identical lesion with surrounding NTF-like areas.

CONCLUSION

While an association between NTF and fibromatosis has recently been reported, this is to our knowledge the first report of an association between NTF and DFSP. The morphologic findings suggest that there may be a continuum between these two CD34-positive lesions that have a tendency to infiltrate adipose tissue and recur.

Gardner's syndrome associated fibromas

Three patients with Gardner's syndrome having benign fibrous proliferations in the soft tissues and the oral cavity are presented. Lesions in all three patients were morphologically different. Two excised lesions in Case 1 were histologically identical to nuchal-type fibroma (NTF) and one lesion in this patient was an epidermal cyst. Case 2 had a lesion located in the soft tissues of the shoulder, which was morphologically similar to NTF and, in addition, contained mildly atypical and multinucleated fibroblastic cells. The oral lesion in Case 3 looked like a fibroma and was morphologically different from all fibrous lesions that have ever been described in Gardner's syndrome. The cases in the present report show that the term Gardner's fibroma is just a descriptive name encompassing a spectrum of morphologically different benign fibrous proliferations associated with this syndrome. Therefore, the term Gardner's fibroma should not be used as a specific name for NTF arising in patients with Gardner's syndrome as suggested in the most recent WHO classification of soft tissue and bone tumors.

Solitary sclerotic fibroma of skin: a possible link with pleomorphic fibroma with immunophenotypic expression for O13 (CD99) and CD34

BACKGROUND

Solitary sclerotic fibroma (SF) presents as a well circumscribed dermal nodule, composed of sparse spindle cells with alternating wavy collagen fibers arranged in a storiform pattern. The histogenesis and nature of this histologically distinct lesion are uncertain. Whether this peculiar tumor represents a true hamartoma or a degenerating end of various fibrous lesions such as pleomorphic fibroma (PF), dermatofibroma, or angiofibroma is still controversial. High proliferating index of spindle cells in SF argues against the possibility of being a degenerating end product of another lesion.

METHODS

We studied morphological features and immunoprofile of eight SFs, in comparison with four PFs, one collagenized dermatofibroma, two angiofibromas, and two periungual fibromas. Immunostains for CD34, CD31, O13 (CD99), Factor XIIIa, S-100, CD68 (KP-1), and MIB-1 were carried out using a labeled streptavidin-biotin method with DAKO-automated immunostainer. Paraffin blocks of two SFs were reprocessed for electron microscopic studies. Clinical data of all patients with SF were also reviewed.

RESULTS

Spindle cells and pleomorphic cells in SF and PF showed diffuse immunoreactivity for CD34 and O13 but were negative for CD31, S-100, and CD68. Spindle cells in one dermatofibroma and one angiofibroma were positive for Factor XIIIa. Proliferating index (MIB-1) was very low in all cases of SF, contradicting some previous reports.

CONCLUSIONS

SF is a fibrotic lesion with cells positive for CD34 and O13. It shares a common immunoprofile with PF but is distinct from dermatofibroma and other common spindle cell lesions of skin. O13 expression in SF has not been previously described.

Gastrointestinal polyposis in childhood: clinicopathologic and genetic features

Gastrointestinal polyps and certain extraintestinal lesions in children may herald a hereditary polyposis syndrome, with an increased risk of neoplasia and other health problems for both children and their relatives. The availability of molecular/genetic screening tests has increased early diagnosis of younger members of known polyposis families. This article reviews the gross and microscopic features of polyposis syndromes of childhood and summarizes the molecular/genetic advances in this field. Clinical management is also briefly discussed.

Collagen-rich tumors of soft tissues: an overview

Although relatively common, soft tissue tumors frequently present diagnostic problems for practicing pathologists. Immunohistochemistry has facilitated the diagnosis of many mesenchymal tumors; however, there is considerable overlap in the staining profiles among cells demonstrating fibroblastic and myofibroblastic differentiation. It has been our experience that soft tissue tumors associated with abundant extracellular collagen deposition commonly cause problems in classification. One reason for this is that tumors displaying this morphology include representatives from different histogenetic families. Specifically, tumors exhibiting fibroblastic, myofibroblastic and even lipomatous differentiation may manifest as a densely collagenous mass. It is the purpose of this review to highlight these collagen-rich soft tissue tumors.