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Soft Tissue Pathology 

Pathology of Nodular Fasciitis

 Dr Sampurna Roy MD        

Path Quiz Case 46: Case history and images

Diagnosis: Nodular Fasciitis





Nodular fasciitis was first described in 1955 by Konwaler et al, as subcutaneous pseudosarcomatous fibromatosis (fasciitis).

Exact cause of the lesion is not known but it is considered to be a selflimiting reactive process rather than a true neoplasm.

Clinical presentation: 

The tumour presents as a rapidly growing nodule (usually present for 1 or 2 weeks), may be associated with  tenderness.

These are usually solitary lesions.

Age: Nodular fasciitis is common in young adults (between 25 and 35 yrs) and less frequently in infants.

Site: In adults, these are commonly located in the upper extremities (flexor surface of the forearm) and the trunk (chest wall and back). In infants, nodular fasciitis is present in the head  and neck region.

Macroscopic appearance: The lesion consists of nodular, nonencapsulated mass usually less than 3cm in diameter. The cut surface may  show  firm and grey white or soft and gelatinous areas.

Visit: Myxoid Tumours of Soft Tissue

Microscopic  examination:


- Fascial type- Poorly circumscribed lesion , extends along the superficial fascia and interlobular septa of subcutaneous fat.

- Subcutaneous type - Well circumscribed lesion,  extends into the subcutis.

- Intramuscular type -  Well circumscribed lesion , grows into the skeletal muscle.

- Intradermal type - Lesion present in the dermis (intradermal fasciitis).

Early cases of Nodular fasciitis display zonation effect  with maturation from the centre (hypocellular or hyalinized) to the periphery (hypercellular with inflammatory cell , blood vessels).

In between, the loose myxoid area is populated by non- pleomorphic myofibroblasts loosely arranged with a tissue culture look .

The backround stroma shows variable myxoid change. Myxoid Tumours of Soft Tissue

Extravasated red blood cells and lymphocytes (not plasma cells) are also present.
Later lesions demonstrate a variety of storiform areas, interconnecting bundles, myxoid areas or focal cystic areas.

Hyalinization and keloidal change may be noted in longstanding cases.

There are 1-2  normal mitotic figures per 5 / HPF (Note: More than 1 mitosis / HPF and atypical forms raises the possibility of a malignant tumour).

Immunohistochemistry :

NF demonstrates focal smooth muscle and muscle specific actin and calponin, but not usually desmin, h-caldesmon or CD34. 

CD68 may be positive in some cases.

Similar microscopic features are present in reactive fasciitis-like lesions occuring.

- In deep soft tissue location,  Example- Nerve, parotid sheath .
- In viscera ,


(i)   Postoperative spindle cell nodule - bladder, prostate, vagina.

(ii)  Inflammatory fibromyxoid tumour - bladder 

(iii) Proliferative funiculitis - spermatic cord

Differential diagnosis:                

A)  Benign tumours:

1.Benign fibrous histiocytoma-

Classical - Epidermal hyperplasia, peripheral collagen bundles, foamy macrophages and Touton giant cells.

Cellular variant- Fascicular spindle cell architecture.

2. Neurofibroma- Architecture is different, S100 protein is positive.

3. Spindle cell lipoma - Fat, ropy collagen, absence of markers

4. Fibromatosis- More infiltrative growth pattern, slender spindle shaped fibroblasts arranged in sweeping fascicles and separated by abundant intercellular collagen.

B) Malignant  tumours:

1. Leiomyosarcoma- The cells in fasciitis are tapered and the nuclei are tapered rather than blunt ended.  Atypical mitotic figures are prominent.

Immunohistochemistry reveals h-caldesmon and desmin positivity.

2. Low grade myofibrosarcoma (myofibroblastic sarcoma) shows focal nuclear atypia,less inflammation,  more uniformly cellular, reaches a larger size and infiltrates muscle.

3. Inflammatory myofibroblastic tumour has fasciitis-like,fascicular and fibrous areas and a marked plasma cell infiltrate.

Immunohistochemistry reveals that some cases are cytokeratin and ALK-1 positive.

4. Myxoid malignant fibrous histiocytoma is multinodular, has vacuolated fibroblasts and shows nuclear pleomorphism, abnormal mitosis, distinct vascular pattern and is usually actin negative (some are CD34 positive).

5. Malignant peripheral nerve sheath tumour has alternating cellular and myxoid fascicles, is more uniform and has wavy buckled and bullet shaped nuclei.

Better differentiated case are at least focally S100 protein positive and myoid markers are negative.

The following features rule out malignant tumour:

1) Absence of atypia 

2) Absence of atypical mitotic figures 

3) Small size 

4) Short history 

5) Superficial location in young adults.


1) Ossifying fasciitis: Nodular fasciitis like fibroblastic proliferations with metaplastic bone formation.

2) Intravascular fasciitis: Involve small or medium-sized veins or arteries.

Histologically the features are similar to nodular fasciitis, however there are  greater number of multinucleate giant cells and less prominent mucoid matrix.

3) Cranial fasciitis: The lesion involves the soft tissue of the scalp land is usually present in infants.

Histologically this is well circumscribed lesion showing NF like fibroblastic proliferation in a prominent myxoid stroma.


Further reading: (Full text articles with images)

Variable Ki67 proliferative index in 65 cases of nodular fasciitis, compared with fibrosarcoma and fibromatosis

Nodular fasciitis of the hand in a young athlete. A case report

Clinical Pathologic Conference Case 3: Nodular Fasciitis

Variable Ki67 proliferative index in 65 cases of nodular fasciitis, compared with fibrosarcoma and fibromatosis

Nodular Fasciitis of the Oral Cavity with Partial Spontaneous Regression (Nodular Fasciitis)

Rapidly Growing Nodular Fasciitis in the Cheek of an Infant: Case Report of a Rare Presentation

Periorbital nodular fasciitis arising during pregnancy

Nodular fasciitis on the zygomatic region: a rare presentation

Articular nodular fasciitis of the right shoulder joint: report of an unusual case with focus on immunohistochemical differential diagnosis

Nodular Fasciitis of the Orbit: A Case Report and Brief Review of the Literature

The chameleon in the neck: Nodular fasciitis mimicking malignant neck mass of unknown primary



Dr Sampurna Roy  MD

Consultant  Histopathologist (Kolkata - India)



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