Rare primary tumor of the breast. Can you provide some images? Did you rule out other breast tumors?

I would extend the IHC panel to rule out carcinoma (AE1/AE3, Cam5.2 and other epithelial markers), melanoma (HMB-45, Melan-A). Is there necrosis?

AE1-AE3 should be negative in the tumor cells. If adjacent normal/benign breast tissue is present, a strong reaction should be seen.

AE1-AE3 is a broad spectrum epithelial marker that stains epithelial tumors (carcinomas) as well as benign breast tissue (e.g. ducts and acini); should be negative in granular cell tumors. What sort of pseudoepitheliomatous hyperplasia? It is not a sort of lesion typical for breast.

The aim of any diagnosis to be correct is to give the, as far as possible, correct treatment. Granular cell tumors have very good prognosis, regardless of grade. If a reasonably wide excision has been done, that should be sufficient. Consideration of melanoma is also relatively pointless from view of therapy if sufficiently wide excision has been done. Some reports are given below:

Recurrence Risk and Margin Status in Granular Cell Tumors of the Breast

A Clinicopathologic Study of 13 Patients: John A. Papalas, MD; John D. Wylie, MD, PhD; Rajesh C. Dash, MD. (Arch Pathol Lab Med. 2011;135:890–895)

The most important thing here is that the patient need not have to worry.

Narayanan Bhattathiri

Granular cell tumors of the breast are predominantly benign with an excellent outcome, but the initial clinical presentation may mimic malignancy.

Very true; no to worry too much

http://www.ncbi.nlm.nih.gov/pubmed/17940129

Br J Radiol. 2007 Dec;80(960):970-4. Epub 2007 Oct 16.

Granular cell tumour of the breast: MRI findings and review of the literature.

Scaranelo AM1, Bukhanov K, Crystal P, Mulligan AM, O'Malley FP.

Author information

Abstract

Granular cell tumours (GCTs) are uncommon, usually benign neoplasms that can mimic malignancy on breast imaging. GCTs can originate anywhere in the body but are most frequently found in the head and neck area, particularly in the oral cavity. When occurring in the breast, as occurs in 5-8% of all cases of GCT, the clinical presentation is similar to that of a primary breast carcinoma. We report a case of granular cell tumour of the breast presenting as a suspicious lesion on breast imaging, and review the MRI features of GCTs.

Eur J Gynaecol Oncol. 2010;31(6):636-40.

Granular cell tumour of the breast: case series and review of the literature.

Mátrai Z1, Langmár Z, Szabó E, Rényi-Vámos F, Bartal A, Orosz Z, Németh M, Tóth L.

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Abstract

Granular cell tumours (GCTs) are uncommon rare neoplasms that may occur in any part of the body. Approximately 5-8% of granular cell tumours occur within the breast. Although nearly always benign in behaviour, granular cell tumours of the breast can often mimic breast malignancies both clinically and on the basis of imaging techniques. This article reports five cases of benign granular cell tumours appearing in the breast, mimicking a malignant breast lesion. In addition to reporting the cases, the relevant literature was reviewed.

Eur J Gynaecol Oncol. 2002;23(4):333-4.

Granular cell tumor of the breast: a rare lesion resembling breast cancer.

Gogas J1, Markopoulos C, Kouskos E, Gogas H, Mantas D, Antonopoulou Z, Kontzoglou K.

Author information

Abstract

Granular cell tumor (GCT) is an uncommon, usually benign tumor that occasionally involves the breast. It is possibly of neural origin (Schwann cells) and usually occurs in premenopausal black women. Physical examination, mammographic, ultrasonographic findings and pathologic examination may suggest breast malignancy. Positive immunohistochemical staining of the cells for S-100 protein, NSE, and CEA is indicative of GCT. Surgical treatment of choice is wide local excision. We report a case of granular cell tumor of a female breast. A 52-yr-old white woman had a palpable mass close to her right axilla. Computer tomography (CT) showed a 3.74 cm mass in the mammary tail of Spencer. The findings were suspicious for malignancy and the lesion was widely resected. Pathologic examination showed granular cell tumor.

Please take the following into consideration:

1. When the total number of cases is small, statistical calculations get complicated. For example, if a p value of

Yes, you are right. The benefit of the patient comes first, and we should do any investigation the result of which can alter the prognosis and treatment.

Ki67

Breast Cancer. 2012 Mar 31. [Epub ahead of print]

Malignant granular cell tumor of the breast: case report and literature review.

Akahane K1, Kato K, Ogiso S, Sakaguchi K, Hashimoto M, Ishikawa A, Kato T, Fuwa Y, Takahashi A, Kobayashi K.

Author information

Abstract

Granular cell tumors (GCTs) are uncommon soft tissue tumors that mostly occur in patients between 40 and 60 years of age and can occur at various body sites. Malignant granular cell tumors (MGCTs) comprise less than 2 % of GCTs and are mostly found on the lower extremities, especially the thighs. These tumors grow more rapidly than benign GCTs, and most importantly, they can metastasize. We describe an MGCT that presented as a right breast mass in a 79-year-old Japanese woman. Local excision was performed for the primary tumor, which was diagnosed as an atypical GCT, but 15 months later, the tumor recurred at the same site. Thereafter, right mastectomy with axillary lymph node dissection was performed. Metastatic disease was identified in 2 of 12 lymph nodes. The pathological examination revealed that the tumor had progressed to an MGCT after recurrence. Multiple liver, lung and bone metastases were revealed 4 months after the second surgery, and the patient died 34 months after the primary surgery. Our findings highlighted the difficulty in diagnosing MGCTs using histological features alone and suggested the usefulness of Ki67 values. A tumor with a high level of Ki67 should be treated as malignant, even if the tumor has few pathological features of malignancy.

GCTs are of Neural origin and as such has a high chance of having multiplicity, and they can occur anywhere in the body where there is a nerve. In a patient with an ulcerated, 'benign looking GCT, a search may reveal another tumour (which may have been there for long and had remained undetected since there was no earlier need to search for it) which get labelled as a 'metastasis from the earlier detected one; then the earlier one will get labelled as 'malignant'. (There is no way to establish mother-daughter relation ship for a suspected primary-metastasis). This could be one reason for at least some of the cases of 'metastasis' from GCT.