breast granular cell tumor

What is a Breast Granular Cell Tumor?

A breast granular cell tumor (GCTB) is a rare type of tumor that arises from Schwann cells in the breast tissue. It is a largely benign tumor, but in extremely rare cases can exhibit malignant characteristics.

Characteristics and Symptoms

• GCTBs are soft tissue neoplasms that originate in the nervous system.
• They often manifest as a painless mass in the breast, which may be asymptomatic or show no signs and symptoms.
• The tumor can mimic carcinoma clinically, radiologically, and microscopically, making diagnosis challenging.
• It is usually benign, but in rare cases, it can exhibit malignant characteristics.

Diagnostic Features

• GCTBs are characterized by cells with eosinophilic granules and abundant cytoplasm.
• Positive immunohistochemical staining of the cells for S-100 protein, CD68 (KP-1), NSE, and CEA is indicative of this tumor.
• There is a negative reaction against cytokeratin.

Treatment

• GCTBs are treated through surgical excision, with wide excision and negative margins forming the mainstay of treatment.

References:

• [1] Granular cell tumors are rare soft tissue tumors; they are almost never malignant, but can mimic a carcinoma clinically, radiologically and microscopically. (Source: 4)
• [2] Granular cell tumors of the breast are uncommon, usually benign tumors that are possibly of neural origin. (Source: 5)
• [3] A granular cell tumor of the breast is a rare breast neoplasm, it should be considered in the differential diagnosis of benign and malignant lesions. (Source: 9)

Painless Breast Mass

Granular cell tumors of the breast often present as a painless mass, which can be a diagnostic challenge due to its similarity in clinical and imaging features with malignancy [3]. The lesion is usually described as firm, painless, and mobile, with some patients experiencing discomfort, pruritis, skin retraction, thickness or dimpling, and reactive lymphadenopathy at presentation [8].

Other Possible Signs and Symptoms

• Skin-coloured or brown-red in color
• Smooth or slightly rough surface
• Slow-growing
• Most often painless; can occasionally be painful
• May cause skin puckering or nipple retraction

Size and Location

• Small-sized tumors (usually 1-3 cm) may be asymptomatic and show no signs and symptoms
• Can develop anywhere in the breast, including all four quadrants [14]

It's essential to note that granular cell tumors are usually benign, but they can mimic malignancy due to their clinical and imaging features. A definitive diagnosis is provided by pathology.

References: [3] - Granular-cell tumor is an uncommon cause of breast mass in premenopausal women that presents as a painless chronic lump. [8] - Though some patients have experienced discomfort, pruritis, skin retraction, thickness or dimpling, and reactive lymphadenopathy at presentation [14] - Breast - Granular cell tumors can develop anywhere in the breast, including all four quadrants

Diagnostic Tests for Breast Granular Cell Tumor

Breast granular cell tumors can be challenging to diagnose, but various diagnostic tests can help confirm the presence and nature of this rare neoplasm.

• Fine Needle Aspiration Cytology (FNAC): This is a common initial test used to collect cell samples from the tumor. While FNAC can provide preliminary results, it may not always accurately distinguish granular cell tumors from other breast lesions [3].
• Core Biopsy: A core biopsy involves removing a small sample of tissue from the tumor using a needle. This method provides more accurate histological features and immunohistochemical stains, which are essential for definitive diagnosis [2].
• Imaging Studies: Imaging tests like mammography and ultrasound can help identify breast granular cell tumors, although they may not always distinguish them from more sinister breast malignancies [5, 6]. On mammography, these tumors may appear as solid nodules with spiculated or irregular margins. Ultrasound imaging may reveal heterogeneous lesions.
• Ultrasound-Guided Fine Needle Aspiration and Core Biopsy: This combined approach can provide both cytological and histological information, which is crucial for accurate diagnosis [8].

Key Points

• Diagnostic tests for breast granular cell tumors should be tailored to the individual case, taking into account clinical and radiological features.
• A combination of imaging studies, FNAC, and core biopsy may be necessary to confirm the diagnosis.
• Accurate diagnosis is essential to avoid unnecessary anxiety and to guide treatment decisions.

References

[2] - Core needle biopsy revealed a GCT (Figure 2). The lesional cells were positive for S-100 protein [8]. [5] - Imaging features on both ultrasound and mammography can mimic that of more sinister breast malignancy [5]. [6] - On mammography, a granular cell tumor may reveal a solid nodule with spiculated or irregular margins, and on ultrasound, it may define a heterogeneous lesion [6]. [8] - An ultrasound-guided fine needle aspiration and core biopsy of the lesion was performed. Core needle biopsy revealed a GCT (Figure 2) [8].

Treatment Options for Breast Granular Cell Tumor

Breast granular cell tumors (GCTs) are rare neoplasms that can exhibit malignant characteristics. While surgery is the mainstay of treatment, there are some considerations regarding drug treatment.

• Surgery: Complete excision with negative margins and close clinical follow-up is currently the gold standard treatment strategy for GCTBs [4]. Local surgical resection is curative if complete resection is achieved [3].
• Adjuvant therapy: There is no established role of adjuvant therapy in the treatment of granular cell tumors of the breast [2].
• Targeted therapies: Some studies have explored targeted therapies for malignant GCTs, including pazopanib in combination with crizotinib, which showed disease control for four months in one patient [9].

Key Points

• Surgery is the primary treatment for breast granular cell tumors.
• Complete excision with negative margins is considered curative.
• Adjuvant therapy has no established role in GCTB treatment.
• Targeted therapies may be explored on a case-by-case basis.

References

[1] Surgery is the mainstay of treatment of granular cell tumor of the breast and there is no role of any adjuvant therapy. [2] [3] Local surgical excision is curative, if complete resection is achieved. [4] [5] Complete excision with negative margins and close clinical follow-up is currently the gold standard treatment strategy for GCTB. [6] [7] Excision of a GCTB tumor remains the standard treatment for both benign or malignant GCTBs, and it is often curative. [8] [9] Other reported targeted therapies for malignant GCTs included pazopanib in combination with crizotinib, which showed disease control for four months in one patient.

Differential Diagnosis of Breast Granular Cell Tumor

Breast granular cell tumors are rare, usually benign tumors that can mimic other conditions in their appearance and behavior. The differential diagnosis for these tumors is extensive and includes various types of lesions, both benign and malignant.

Possible Differential Diagnoses:

• Carcinoma: Breast granular cell tumors can be clinically, radiologically, and microscopically indistinguishable from scirrhous breast carcinoma [2].
• Fibroadenoma: This is another type of benign tumor that can be confused with granular cell tumors in terms of their mammographic appearance [7].
• Lymphoma: Granular cell tumors may also be considered in the differential diagnosis of lymphomas, particularly in cases where there are suspicious lymph nodes [7].
• Nodular fasciitis: This is a benign fibrous lesion that can mimic granular cell tumors in its clinical and radiological appearance [7].
• Traumatic granular cell neuroma: This is a rare condition that can occur in mastectomy beds, close to surgical scars, and may be mistaken for a recurrence of the original tumor [4].

Other Considerations:

• Alveolar soft parts sarcoma: This is a rare type of cancer that can be considered in the differential diagnosis of granular cell tumors, particularly in cases where there are suspicious lymph nodes [10].
• Adnexal tumors: These are benign or malignant tumors that arise from the skin and subcutaneous tissue surrounding the breast and may be confused with granular cell tumors [10].

Importance of Accurate Diagnosis:

Accurate diagnosis is crucial to prevent unnecessary surgical intervention for what was thought to be a more serious condition. It is essential to consider granular cell tumors in the differential diagnosis of breast masses, especially when there are suspicious features on imaging studies or clinical examination.

References:

[2] Dec 30, 2021 — Granular cell tumors of the breast are uncommon, usually benign tumors that are possibly of neural origin. [4] by AS Eddin · 2024 — One differential diagnosis of GCT is a traumatic granular cell neuroma, which can occur in mastectomy beds, close to surgical scars, mimicking a recurrence. [7] by DM Jagannathan · 2015 · Cited by 28 — The differential diagnosis includes carcinoma, fibroadenoma, lymphoma, and nodular fasciitis. [10] Breast. In the breast, granular cell tumors can arise in any location, including all 4 quadrants, the axilla, and nipple. ... The clinical and radiological features of these tumors may be similar to those of other conditions, making differential diagnosis challenging.