Atypical and malignant granular cell tumors in Japan: a Japanese Musculoskeletal Oncology Group (JMOG) study

Histopathological, Immunohistochemical and Clinical Features of Granular Cell Tumors: Re-Evaluation of Malignancy Criteria in a Series of 54 Tumors

Aim. Granular cell tumors (GCTs) are mostly benign. Malignant GCTs are extremely rare. Although the criteria proposed by Fanburg-Smith et al are widely used, some authors do not find them especially useful. We aimed to present our GCT case series consisting of 54 patients from 2 institutions during a 22-year period and evaluate these tumors according to these criteria of malignancy. Materials and Methods. Fifty-four patients with GCT diagnosed between 2000 and 2024 were retrospectively reviewed. All hematoxylin/eosin-stained slides were evaluated for spindling pattern, nucleolar prominence, pleomorphism, geographical necrosis, increase in nuclear/cytoplasmic ratio, and mitotic index. Results. Overall, 7 tumors were classified as "Malignant GCT." Histopathologically all malignant tumors showed nucleolar prominence and pleomorphism. Ki-67 proliferation index was 3% or higher in 6 tumors. In 4 of the malignant GCTs, lymph node metastasis was present at the time of diagnosis. In 2 of these patients, lung metastasis and in 1 patient liver metastasis were also found. Another malignant tumor showed bone invasion. In one of the malignant tumors, local recurrence, lymph node metastasis, and lung metastasis occurred 1 year after excision. Conclusions. Malignant GCTs had behaved as frequently metastasizing high-grade sarcomas.

Intramuscular granular cell tumor in the sternocleidomastoid muscle: A case report and literature review

Granular cell tumor (GCT) is a rare soft-tissue neoplasm that originates from Schwann cells. Most cases occur in the subcutaneous or submucosal regions, and intramuscular GCT is even more uncommon. Herein, we describe an atypical GCT growing in the sternocleidomastoid muscle. A 41-year-old Chinese man was admitted to our hospital for a right neck mass. In magnetic resonance images, the mass showed higher signal intensity than the adjacent normal muscle on T2-weighted images and intermediate signal intensity on T1-weighted images. Slightly enhanced and higher signal intensity was observed in the peripheral rim on contrast-enhanced fat-sat T1-weighted images, and the "stripe sign" was evident. The tumor was completely resected, and pathological examination indicated an atypical GCT. The patient tolerated the procedure well. This is a rare case report of an intramuscular GCT from diagnosis to treatment. Magnetic resonance imaging might help diagnose such tumors, and we review different magnetic resonance imaging characteristics of intramuscular GCTs at other sites.

Malignant granular cell tumor of chest wall: a case report

Background

Granular Cell Tumors (GCTs), also known as Abrikossoff tumors, are rare neoplasms that typically originate from Schwann cells. These tumors most commonly occur in the head and neck region, particularly the tongue. While GCTs are generally benign, less than 2% of cases exhibit aggressive biological features such as rapid growth, high recurrence rates, and metastasis. In this report, we present a rare case of a Malignant Granular Cell Tumor (MGCT) of the chest wall, which posed significant challenges in both characterization and management.

Case Presentation

A fifty-year-old man underwent an ultrasound examination for a nodular mass on his right chest wall. The ultrasound revealed a firm, hard mass measuring 2 cm x 2 cm with an uncertain diagnosis. A fine-needle aspiration biopsy (FNAB) guided by ultrasound was performed, resulting in a diagnosis of Abrikossoff tumor. The patient subsequently underwent radical excision of the mass, which confirmed the initial diagnosis. Nine months after surgery, a new mass with similar characteristics was detected during a physical examination. The patient underwent a second surgery, but this time the histopathological examination was negative for neoplastic cells. However, another mass appeared at the same site as the previous surgical excision. A CT scan and MRI of the right chest wall confirmed the presence of a 2 cm x 2 cm nodular mass. The patient then underwent a deeper excision. Histomorphological and immunohistochemical assessments confirmed the recurrence of MGCT.

Conclusion

This case highlights the malignant potential of GCTs. The numerous local recurrences necessitated three surgeries and additional procedures. The aggressive nature of this pathology underscores the complexity of managing these tumors, which are poorly understood and lack proven post-operative strategies for controlling local and distant disease.

Antiangiogenics in Malignant Granular Cell Tumors: Review of the Literature

Granular cell tumors (GCT) represent 0.5% of all soft tissue sarcomas (STS), and when metastatic, they exhibit aggressive behavior and determine limited survival. Metastatic GCTs are relatively chemo-resistant; however, there is growing evidence of the benefit of using pazopanib and other targeted therapies in this histology. This is a review of the role of pazopanib and other targeted therapies in the treatment of GCTs, along with some insights on pathology and molecular biology described in GCTs. From 256 articles found in our search, 10 case-report articles met the inclusion criteria. Pazopanib was the most employed systemic therapy. The median reported time on therapy with pazopanib was seven months. Eight out of ten patients (80%) experienced disease control with pazopanib, while four out of ten (40%) patients achieved an objective RECIST response. Molecular studies suggested that antitumoral effects of pazopanib in GCT might be due to a loss-of-function of ATP6AP1/2 genes which consequently enhance signaling through several molecular pathways, such as SFKs, STAT5a/b, and PDGFR-β. Other reported targeted therapies for malignant GCTs included pazopanib in combination with crizotinib, which showed disease control for four months in one patient, and a PI3K inhibitor which achieved disease control for nine months in another patient. Dasatinib and megestrol were ineffective in two other different patients. Pazopanib has been demonstrated to be active in advanced GCTs and may be considered as a preferable treatment option.

Recurrent primary cutaneous granular cell tumor of the neck in an Asian women: A case report

INTRODUCTION AND IMPORTANCE

Granular cell tumors are uncommon neoplasms. They appear in the skin, subcutaneous tissues, and many internal organs. It is essential to diagnose this disease because it mimics other tumors clinically. We report this case because of the rarity of tumors in Asians and the necessity of excision with clear margins.

CASE PRESENTATION

A 55-year-old Indian woman reported swelling in the right side of the neck for six months and gradually increasing in size. Two years ago, she had a similar swelling excised from her neck. She had wide local excision of the tumor with wider margins in the plastic surgery department, and histopathology revealed a granular cell tumor with clear margins. She is undergoing close follow-up with history and physical examination with no evidence of disease recurrence.

CLINICAL DISCUSSION

Granular cell tumors can have recurrences. These slow-growing tumors appear benign. Histopathological examination with careful assessment of high-risk features is vital in evaluating Granular cell tumors. Wide local excision with clear margins is the mainstay of treatment.

CONCLUSION

Achieving clear margins in the head and neck area is sometimes tricky for granular cell tumors. Margin positivity is associated with a high risk of local recurrence and needs re-excision of the tumor for adequate local control.

Granular Cell Tumor of the Hand: Unusual Malignancy of a Previous Benign Lesion: A Case Report

CASE

Malignant granular cell tumors are uncommon soft-tissue tumors. We describe a granular cell tumor that presented as a benign hand nodule diagnosed by biopsy and image. The patient refused local excision. After 15 years, the patient came back because of symptomatic growth, and a malignant granular cell tumor was diagnosed, with metastatic disease. Despite surgical disarticulation and adjuvant treatment, she died after 8 months. The pathological examination revealed the tumor had progressed to malignant behavior.

CONCLUSIONS

Our findings highlight the importance of a closer follow-up. Although unusual, we must be aware of the possibility of a change of behavior from benign to malignant granular cell tumor.

Review and update in the diagnosis of peripheral nerve sheath tumors

PURPOSE OF REVIEW

Although tumors with nerve sheath differentiation are vast, the main clinically significant problems faced by the pathologist are the separation of malignant peripheral nerve sheath tumors (MPNSTs) from histologic mimics, the diagnosis of neurofibromatous neoplasms with atypical features, and the separation of cutaneous neurofibromatous neoplasms from melanoma. This review briefly discusses a variety of common nerve sheath tumors and summarizes recent advances on these diagnostic fronts.

RECENT FINDINGS

Much of recent work has focused on abnormalities in polycomb repressive complex 2, and the ways in which these abnormalities may be exploited in the diagnosis of MPNSTs. Progress has been made in the diagnostic and clinical understanding of atypical neurofibromatous neoplasms and low-grade MPNSTs. A number of reports have explored the diagnostic distinction between cutaneous neurofibroma and melanoma.

SUMMARY

New discoveries show promise in the diagnosis of peripheral nerve sheath tumors, but challenges - old and new - remain.

A Case of Synchronous Malignant and Benign Granular Cell Tumor of the Vulva

Granular cell tumors (GCT) are rare soft tissue neoplasms, which seldom occur in the vulva. They are more commonly benign, but malignant GCT do occur. We report a case of a 50-yr-old postmenopausal woman who presented with a vulvar lesion that was diagnosed as GCT on biopsy. Imaging and clinical examination revealed an enlarged, likely positive lymph node. Pathology of the subsequently resected total deep vulvectomy specimen showed 2 histologically distinct GCTs. The larger lesion met criteria for malignancy and histologically corresponded to metastatic deposits seen in the pelvic lymph nodes. The separate smaller lesion was histologically benign. This case illustrates a malignant GCT with a synchronous, likely benign GCT both occurring in the vulva. Our case demonstrates the application of histologic criteria in the diagnosis of malignant and benign GCT with discussion on the diagnosis and treatment of this rare tumor.

Benign and Malignant Granular Cell Tumor of the Hypopharynx: Two Faces of a Rare Entity

Granular cell tumors (GCT) are rare soft tissue tumors that involve the head and neck in 50% of patients. Two distinct variants of GCT, one benign (bGCT) and the other malignant (mGCT), involving the hypopharynx, a subsite of the larynx, are presented here. The clinical presentations, radiographic features, pathologic diagnosis in these two variants of GCT are discussed. The mGCT was diagnosed only after complete tumor excision. This report highlights the importance of complete excision of the tumor mass, as diagnosis of mGCT can be exceedingly difficult to make on a small biopsy specimen. Therefore, complete excision is recommended for definitive diagnosis and treatment of GCTs.

Granular cell tumor a study of 42 cases and systemic review of the literature

BACKGROUND

Granular cell tumor (GCT) remains a diagnostic clinicopathologic problem because the exact frequency of its detailed morphological and clinical characteristics is unknown as most observations are collected from small series or isolated cases. Herein, our aim is to highlight the frequency of all clinicopathological characteristics of this rare tumor based in our series and the available medical (PubMed) literature.

MATERIAL AND METHODS

42 cases were evaluated for: tissue layers involved by the tumor (in skin and mucosae), growth pattern, nuclear pleomorphism, mitotic index, necrosis, spindling, calcification, hyalinization, and pustule-ovoid bodies of Milian, as well as perineural and vascular invasion, and the presence of adjacent epithelium changes, and lymphocytes and eosinophils infiltration., Follow-up was analyzed. The tumors were subclassified into benign, atypical and malignant according to Fanburg-Smith criteria and into benign or GCT of uncertain malignant potential according to Nasser criteria. The same characteristics were analyzed for 1499 cases reviewed according to PRISMA guidelines.

RESULTS

In the current series, the mean age at diagnosis was 45.8 years (range 6-69 years). Most patients were females (60 %) and the involved organs were by descending frequency: skin and subcutaneous tissue, bronchus, esophagus, breast, tongue, larynx, pharynx, gingiva, trachea, right colon, vulva, and hypopharynx. No recurrence or progression was seen, despite 32 cases were incompletely excised, with the exception of one malignant tumor. The growth pattern was either infiltrative (85.71 %) or well limited (7.14 %). Sixteen tumors had vesicular nuclei. Mitotic activity was found in two tumors. Lymphocytic infiltration was found in 14 tumors. Eosinophils were present in 6 cases. One GCT of the right colon showed extensive calcification and hyalinization. Perineural invasion was noted in 6 lesions. No vascular invasion was found. One tumor was clinically malignant and the patient died 2 years after diagnosis. Medical literature review showed similar results in terms of frequency of the reported clinical and morphological features. Among cases with available follow up, almost 20 % showed positive margins and of those 20 % developed local recurrence. According to the Fanburg-Smith criteria, 72 % would be benign, 17 % atypical and 11 % malignant tumors, while according to those of Nasser, 93 % would be benign and 7% of uncertain malignant potential. However, true malignancy, as affirmed by metastasis of GCT is found in almost 2.5 % of the cases.

CONCLUSION

GCT is a usually benign tumor, affecting any anatomic location. Necrosis and mitotic activity seem to be the most effective histologic criteria for detecting aggressive tumors, but the presence of metastasis (2.5 % of the cases) remains the most accepted definitive criterion for diagnosis of malignant GCT.

What's new in nerve sheath tumors

Peripheral nerve sheath tumors are commonly encountered and frequently pose challenges to the pathologist and the clinician. This review discusses the wide range of entities with an emphasis on new discoveries in the past decade. Clinical, histologic, immunohistochemical, and pathogenetic findings are discussed with an emphasis on clinical implications and differential diagnosis.

Metastasizing Malignant Granular Cell Tumor (Abrikossoff Tumor) of the Anterior Abdominal Wall, with Prolonged Survival

Malignant granular cell tumor (MGCT) is a rare high-grade mesenchymal tumor of Schwann cell origin. MGCTs commonly affect thigh, extremity, and trunk; however, involvement of the abdominal wall is quite rare. It has poor prognosis with 39% mortality rate in 3-year interval. We report a 50-year-old female who had MGCT arising in the anterior abdominal wall and developed massive metastatic deposits in both lungs and in the right inguinal lymph nodes, with prolonged survival for 11 years. A brief review of the literature is presented.

Malignant granular cell tumor of the median nerve: a case report with a literature review of 157 cases

Malignant granular cell tumors are an extremely rare, high-grade sarcoma with a schwannian phenotype and are composed of malignant granular cells with cytoplasmic lysosomal inclusion. To date, 157 cases of malignant granular cell tumors have been reported. We report the first case of a malignant granular cell tumor arising from the digital nerve to the median nerve in the palm, and we review the 157 previously reported cases and summarize the clinical profile, treatment, and outcome of this tumor. The median age, tumor size, and follow-up periods were 51 years, 6 cm, and 24 months respectively. With respect to the oncological result, 53 patients (33.8%) had no evidence for disease, 31 (19.7%) were alive with the disease, and 51 (32.5%) died because of the disease. Our case report indicates that rare malignant tumors can arise from the digital nerve to the median nerve in the palm, an anatomical site that is usually affected by benign lesions. Exhaustive discussions between surgeons and pathologists are necessary for the treatment of this rare malignant tumor.

Malignant granular cell tumor: Clinical features and long-term survival

BACKGROUND

Malignant granular cell tumor GCT (mGCT) has not been well described. We sought to investigate associations between tumor characteristics, treatments and survival.

METHODS

Patients diagnosed with mGCT years 1995-2014 were identified using the Surveillance, Epidemiology and End Results database. Descriptive statistics regarding tumor and treatment characteristics were calculated. Chi-square tests determined associations between tumor location and features. Survival analyses included Kaplan-Meier functions and Cox proportional hazard ratios (HR).

RESULTS

Of 113 patients included, median age was 54 years and 77.0% were female. Frequent tumor sites included soft tissues (36.3%), ovary/testis (16.8%), and skin (11.5%). Median tumor size was 4.0 cm. Metastases to regional lymph nodes (12.5%) and distant sites (11.4%) occurred. Treatments included surgery (85.0%), radiotherapy (12.4%) and chemotherapy (8.9%). Overall five and 10-year cause-specific survival was 74.3% and 65.2%, respectively. Survival was worse for patients with tumors >5 cm compared to those with tumors ≤5 cm (HR = 34.03; 95% confidence interval [CI]: 2.57-450.17), and patients with metastasis (HR = 15.25; 95% CI: 1.19-195.72) compared with those without metastasis. Patients who underwent surgery had superior survival than those who did not (HR = 0.13; 95% CI: 0.05-0.34).

CONCLUSIONS

Particular tumor features and treatments are associated with superior survival. This information may be used to more accurately estimate prognosis.

Isolated limb infusion as a treatment option for malignant granular cell tumour

A 54-year-old man presented with a painful lesion on the right posterior calf with MRI identifying a 5 cm lesion in the medial head of the gastrocnemius. He underwent wide local excision of the tumour, and the final pathology was consistent with atypical granular cell tumour. Three years later, he developed a recurrent right popliteal mass. Complete staging workup also identified multiple lung nodules and a caecal polyp that were consistent with metastatic granular cell tumour. He was started on pazopanib and deemed a poor candidate for palliative resection due to encasement of the popliteal vessels. The patient refused above-the-knee amputation (AKA) at that point and was evaluated for isolated limb infusion as an alternative. He received three cycles of isolated limb infusion within a 2-year period and achieved good response from the first two cycles. He underwent AKA 4 years after his diagnosis of malignant granular cell tumours and is currently doing well.

Adjuvant radiation therapy for malignant Abrikossoff's tumor: a case report about a femoral triangle localisation

Background

Granular cell or Abrikossoff’s tumors are usually benign however rare malignant forms concern 1 to 3% of cases reported. Pelvic locations are exceptional.

Case presentation

We report a case of a 43-years-old patient who had a benign Abrikossoff’s tumor localized in the right femoral triangle diagnosed at the biopsy. The patient underwent a surgical tumorectomy and inguinal lymph nodes resection. Histologically, the tumor showed enough criteria to give diagnosis of malignancy: nuclear pleomorphism, tumor cell spindling, vesicular nuclei with large nucleoli. Moreover, five lymph nodes were metastatic. Immunohistochemistry findings confirmed the diagnosis of granular cell tumor which is positive for S100 protein and CD68 antibodies. The mitotic index was nevertheless low with a Ki67 labeling index of 1–2%. A large surgical revision with an inguinal curage following radiotherapy were decided on oncology committee. Adjuvant radiotherapy on the tumor bed and right inguinal area of ​​50 Gy in conventional fractionation was delivered with the aim of reducing local recurrence risk. There was no recurrence on longer follow-up (10 months post radiotherapy).

Conclusions

Adjuvant radiotherapy seems an appropriate therapeutic approach, even if controversial, given that some authors report effectiveness on local disease progression.