Spindle Cell Tumors of the Sinonasal Tract: A Diagnostic Update with Focus on Ancillary Workup

Spindle cell neoplasms arising in the head and neck may be challenging to recognize due to their relative rarity. While underlying molecular alterations are increasingly elucidated, testing for these features may not be readily available. In most cases, combinations of key morphologic features and diagnostic immunohistochemical markers can be used to replace molecular diagnostics. Conversely, some molecular alterations and expression of their surrogate biomarkers are not specific for any one entity, and it is important to recognize these to avoid diagnostic pitfalls. In this review, we discuss both old and new spindle cell tumors of the sinonasal tract, with an emphasis on histologic features and clinically relevant immunohistochemical markers serving as surrogate markers for underlying genomic alterations.

A report of a rare case of paratesticular spindle cell rhabdomyosarcoma in an adult patient

Paratesticular embryonal rhabdomyosarcoma is a rare malignancy developed from a mesenchymal tissue of spermatic cord, testicular components. Spindle cell rhabdomyosarcoma (SCR) is a variant of embryonal rhabdomyosarcoma affecting the paratesticular region of adult patients and is even rarer. Given the limited guidelines available to manage SCR and the rarity of reported cases, our report aims to discuss a new case of this entity in a 66-years old Moroccan patient. Paratesticular SCR is a very rare tumor and requires attention from urologists to consider this entity as differential diagnosis when suspecting malignancies in the urogenital region.

Clinical-pathologic profile of head and neck rhabdomyosarcoma in children: a systematic review

This systematic review aimed to analyze the clinicopathological profile and relevant prognostic factors of head and neck rhabdomyosarcoma in pediatric patients. The search was carried out in the electronic search portals PubMed, Lilacs, Embase, Scopus, and Web of Science. The search yielded studies that were then analyzed regarding study topic, data extraction, and risk of bias using the STROBE (Strengthening the Reporting of Observational Studies) guidelines. Finally, three studies were included for qualitative analysis. Most of the cases involved embryonic and alveolar rhabdomyosarcoma. Expression of MYOD1 was highly correlated with diagnosis of spindle cell/sclerosing rhabdomyosarcoma, which appears to have a poor prognosis in children. Furthermore, tumor size <5 cm and absence of metastasis accompanied by complete resection and administration of adjuvant therapies such as chemotherapy and radiotherapy favored a better prognosis.

Congenital spindle cell rhabdomyosarcoma: An international cooperative analysis

BACKGROUND

Spindle cell rhabdomyosarcoma (RMS) is a rare variant of RMS accounting for up to 10% of cases in infants. In older children and adults, spindle cell RMS is associated with MYOD1 mutations and a poor prognosis. In infants, it is associated with recurring fusions involving NCOA2 and VGLL2. Reports in the literature suggest a favorable prognosis for this subset, however, little is known about treatment and outcome data of infants with spindle cell RMS.

METHODS

Characteristics, treatment, and outcome of an international cohort of 40 patients aged ≤ 12 months with spindle cell RMS treated from 1997 to 2018 were evaluated.

RESULTS

Localized disease (LD) was diagnosed in 39 patients. The median age at diagnosis was 2.5 months (range 0-12 months). Expert pathologic review confirmed the diagnosis of spindle cell RMS in all patients. Among 26 tumors that had molecular evaluation, 13 had rearrangements of NCOA and/or VGLL. Multimodal treatment of infants with LD included conventional (age adjusted) chemotherapy (n = 37), resection (n = 31) and radiotherapy (RT) (n = 5, brachytherapy in 3). Complete remission was achieved in 37/39 patients. Progressive disease occurred in two infants, relapsed disease in three. Microscopically complete surgical resection was associated with five-year event-free survival (EFS) and overall survival (OS) of 100%. Two patients with tumors ≤ 5 cm were treated with microscopically complete resection only and were alive 1 and 4.2 years after diagnosis. The 5-year EFS and OS for infants with LD were 86% (±11; CI 95%) and 91% (±9; CI 95%), respectively. One patient had metastatic disease (NCOA fusion positive) with primary tumor in head and neck and brain metastases. This patient died despite chemotherapy and delayed resection of the primary tumor due to respiratory failure secondary to cytomegalovirus infection 1.2 years after diagnosis.

CONCLUSION

Infants with spindle cell RMS have an excellent prognosis. Multimodal treatment including microscopically complete resection of the tumor is strongly recommended.

Tongue Spindle Cell Rhabdomyosarcoma: A Rare Case Report and Literature Review

Rhabdomyosarcoma (RMS) is a malignant soft tissue neoplasm with its origin in the skeletal muscle and is extremely rare in adults. By the World Health Organization (WHO), a new variant of RMS has been classified, i.e. the spindle cell (Sc) and sclerosing (S) RMS. While the Sc-RMS shows intersecting fascicles of nonpleomorphic spindle cells, the S-RMS is characterized by a marked hyalinization in a pseudovascular growth pattern associated with round-to-spindled tumour cells. According to the analysed data, the Sc/S-RMS variant has a worse outcome than other variants. The new classification of the Sc/S-RMS variant is valuable to the clinical practice. There are not many oral Sc/S-RMS cases reported. The aim of this paper is to demonstrate that an early diagnosis, an adequate treatment and a multidisciplinary approach have a positive effect on the prognosis of the patient. In this study, we analyse a new case of Sc-RMS variant in a young adult with an early diagnosis and a favourable outcome as a result of an appropriated multidisciplinary treatment: early surgery, radiotherapy and chemotherapy treatment.

Nasal spindle cell tumor with rhabdomyoblastic features: A rare and diagnostically difficult case

Nasal spindle cell rhabdomyosarcoma is very rare. The tumor is sometimes confused with other spindle cell tumors. We herein report a case of nasal spindle cell tumor in a 62-year-old woman. The patient first presented herself to a medical doctor’s office after an episode of left epistaxis. An intranasal tumor was found and resected. The tumor was composed of spindle cells, and she was diagnosed with desmoid-type fibromatosis. Five years after the initial episode, an intranasal tumor was found again. The tumor showed a fascicular growth pattern with high cellularity and was predominantly composed of spindle cells. Scattered eosinophilic rhabdomyoblasts were also observed. She was diagnosed with spindle cell rhabdomyosarcoma. This is a unique case report not only because nasal spindle cell rhabdomyosarcoma is very rare but also because the tumor was initially diagnosed as desmoid-type fibromatosis. It is important to consider spindle cell rhabdomyosarcoma as a differential diagnosis of nasal spindle cell tumors.

Primary Rhabdomyosarcoma of the Breast: Study of Three Cases at One Institution with a Review of Primary Breast Sarcomas

BACKGROUND

Primary breast sarcoma (PBS) is rare, comprising approximately 1% of breast malignancies. Rhabdomyosarcoma (RMS) accounts for an extremely small proportion of PBSs, often leading to delayed histologic confirmation.

METHODS

Upon reviewing Asan Medical Center's pathology database between 2000 and 2018, 41 PBS cases were retrieved, including three cases of primary RMS of the breast. Their clinicopathological features were analyzed, and the literature related to PBS and primary RMS of the breast was reviewed.

RESULTS

We identified three primary breast RMS cases from our institution database, comprising 7.3% of PBS: one case each of spindle cell/sclerosing RMS (ssRMS), alveolar RMS (aRMS), and embryonal RMS (eRMS). All cases involved adolescents or young adults (14, 16, and 25 years, respectively) who underwent mastectomy or radiotherapy and were confirmed using immunohistochemical testing for myogenin, desmin, and myogenic differentiation. The ssRMS patient experienced recurrence at the operation site 4 months post-surgery despite undergoing concurrent chemoradiotherapy. The aRMS patient had multiple metastases at diagnosis and showed FAX3-FOXO1 fusion transcripts; she died 22 months after the diagnosis. The eRMS patient had enlarged axillary lymph nodes; post-radiotherapy, the lesion recurred as multiple metastases to the bone and lung. She died 18 months post-diagnosis.

CONCLUSIONS

Our experience on RMS cases suggests that spindle cell or small round cell malignancy in breasts of young female should raise suspicion for the possibility of primary or secondary RMS. To our knowledge, this is the second report of primary breast ssRMS and it may help clinicians who encounter this rare disease in the future.

WITHDRAWN:Primary Rhabdomyosarcoma of the Breast: A Report of Two Cases and Literature Review

Ahead of Print article withdrawn by publisher.

A clinicopathologic study of head and neck rhabdomyosarcomas showing FOXO1 fusion-positive alveolar and MYOD1-mutant sclerosing are associated with unfavorable outcome

BACKGROUND

Based on their distinctive histologic and genetic features, the latest WHO classification of soft tissue tumors includes four pathologic variants of rhabdomyosarcoma (RMS): embryonal (ERMS), alveolar (ARMS), spindle cell-sclerosing (SRMS-ScRMS) and pleomorphic RMS. The aim of this study focused on a detailed clinicopathologic and survival analysis of head and neck RMS (HNRMS) using the latest pathologic and molecular criteria reflecting this new subclassification in a large cohort.

PATIENTS AND METHODS

Patients managed for HNRMS in our institution (1996-2015) were analyzed. The presence of a FOXO1 fusion was required for the classification of ARMS. MYOD1 mutations in SRMS-ScRMS were tested when material available. Univariate and multivariate analyses were performed to evaluate variables related to overall survival (OS).

RESULTS

Ninety-nine HNRMS patients (52 males and 47 females, mean of 16years) were included in the study after pathologic re-review. The most common location was parameningeal (PM) (n=64), followed by non-orbital/non-PM (n=25) and orbital (n=10). There were 53 ERMS, 33 fusion-positive ARMS and 13 SRMS-ScRMS [SRMS (8); ScRMS (5)]. The 5-year OS rate for ERMS patients was significantly higher (82%) compared to ARMS (53%) and SRMS-ScRMS (50%) [SRMS (75%); ScRMS (30%)]. Univariate analysis showed that survival was dependent on histology (P=0.012), tumor size >5cm (P<0.001), regional lymph node involvement (P=0.002), metastasis at initial presentation (P<0.001), stage (P<0.001), and recurrence (P=0.002). Multivariate analysis confirmed histologic subtype to be significant (P=0.043).

CONCLUSION

Our findings reinforce that HNRMS is a heterogenous disease with ARMS and SRMS-ScRMS having an equally unfavorable outcome.

Spindle cell rhabdomyosarcoma in the hypopharynx of an adult

We herein present the first-reported case in the English-language literature of a spindle cell rhabdomyosarcoma in the hypopharynx of an adult. A 58-year-old male presented with a progressive, 7-month history of discomfort during swallowing, accompanied by hoarseness for 1 month. Computed tomography and magnetic resonance imaging revealed a tumor in the left pyriform sinus; frozen section evaluation suggested that it was rhabdomyosarcoma. The tumor was removed completely via left lateral cervical incision. Section margins were negative, and laryngeal function was preserved. The postoperative pathological results indicated spindle cell rhabdomyosarcoma. The patient received postoperative radiotherapy (6,000 cGy in 200 cGy fractions, delivered over 30 days). However, he was also required to undergo urgent tracheostomy due to severe laryngeal obstruction, precipitated by laryngeal edema, 3 months subsequent to radiotherapy. The patient was free of disease 25 months postoperatively but is still unable to close his tracheostomy.