Cytologic features of alveolar soft part sarcoma: report of three cases

Soft Tissue Fine-Needle Aspiration: Current and Future Impact on Patient Care

Soft tissue neoplasms pose many diagnostic challenges on fine-needle aspiration (FNA), owing largely to their rarity, large number of entities, and histologic diversity. Advances in ancillary testing now allow detection of the characteristic immunophenotypes and molecular alterations for many neoplasms and include reliable surrogate immunohistochemical markers for underlying molecular events that are highly efficient in small biopsies. A morphology-based framework is recommended to guide appropriate differentials and judicious selection of ancillary tests for small biopsies. The accurate diagnosis of soft tissue tumors is crucial for patient management and prognostication, with many potential implications in this era of precision medicine.

Three-dimensional structural analysis of papillary thyroid carcinoma nuclei with serial block-face scanning electron microscopy (SBF-SEM)

Nuclear morphology of carcinoma cells is critical for the pathological diagnosis of papillary thyroid carcinoma (PTC). However, three-dimensional architecture of PTC nuclei is still elusive. In this study, we analyzed the three-dimensional ultrastructure of PTC nuclei using serial block-face scanning electron microscopy which takes advantage of the high-throughput acquisition of serial electron microscopic images and three-dimensional reconstruction of subcellular structures. En bloc-stained and resin-embedded specimens were prepared from surgically removed PTCs and normal thyroid tissues. We acquired two-dimensional images from serial block-face scanning electron microscopy and reconstructed three-dimensional nuclear structures. Quantitative comparisons showed that the nuclei of carcinoma cells were larger and more complex than those of normal follicular cells. The three-dimensional reconstruction of carcinoma nuclei divided intranuclear cytoplasmic inclusions into "open intranuclear cytoplasmic inclusions" connecting to cytoplasm outside the nucleus and "closed intranuclear cytoplasmic inclusions" without that connection. Cytoplasm with abundant organelles was observed in open inclusions, but closed inclusions contained fewer organelles with or without degeneration. Granules with a dense core were only observed in closed inclusions. Our observations suggested that open inclusions originate from nuclear invaginations, and disconnection from cytoplasm leads to closed inclusions.

Revisiting cytomorphology, including unusual features and clinical scenarios of 8 cases of alveolar soft part sarcoma with TFE3 immunohistochemical staining in 7 cases

OBJECTIVES

To present a comprehensive analysis of cytomorphological features, including clinical scenarios, for 8 cases (4 males, 4 females, aged 17-39 years, average = 28.5) of, retrospectively diagnosed alveolar soft part sarcoma (ASPS), with TFE3 immunostaining in 7 cases.

METHODS

Conventional Papanicolaou and May Grunwald-Giemsa (MGG) stained smears and corresponding tissue sections were critically reviewed. Fine needle aspiration cytology was performed for primary diagnosis in 6 cases and for metastatic lesions in 2 cases. TFE3 and other immunohistochemical stains were tested using polymer detection technique.

RESULTS

Tumour sites were thigh (n = 6), shoulder (1) and neck (1). Tumour size (n = 6) varied from 5 to 14.5 cm (average = 7.2). Seven out of 8 cases were correctly diagnosed on cytosmears. The smears were mostly hypercellular (5), composed of cohesive clusters (8), including cell balls and pseudopapillae (3) and singly scattered cells (8). Tumour cells were round to oval, containing central to eccentric nuclei (8), abundant granular (8) to finely vacuolated (7) cytoplasm that was ill- to well-defined, intracytoplasmic rod-like or needle-shaped crystals (3) and prominent nucleoli (8), Additionally, there were binucleated cells (7), multinucleation (2), intracytoplasmic inclusions (3), intranuclear inclusions (2), intercellular stroma (5) and bare nuclei (8). Immunohistochemically, 7/8 tumours were positive for TFE3.

CONCLUSIONS

This constitutes the largest series describing cytomorphological spectrum of ASPS with TFE3 immunostaining results. Frequently observed features and rod-like/needle-shaped crystals on MGG smears, can help to differentiate ASPS from its mimics. TFE3 immunostaining aids in substantiating diagnoses, in an appropriate clinicoradiological context.

Needle biopsy of mesenchymal lesions of the head and neck: Evolving concepts and new strategies for diagnosis

Sarcomas are a rare and heterogeneous group of neoplasms that can be a significant diagnostic challenge in routine practice. Recent advances in the understanding of molecular mechanisms underlying oncogenesis have led to an array of novel diagnostic tools. Here we review several sarcomas of the head and neck region, focusing on neoplasms with new molecular findings and highlighting novel diagnostic tools.

Cytopathology of alveolar soft part sarcoma: a report of 10 cases

BACKGROUND

Alveolar soft part sarcoma (ASPS) rarely is subjected to cytopathologic evaluation. With the exception of some very small series, the literature is limited to case reports. The objectives of the current study were to evaluate the cytomorphology of 10 ASPS cases on fine-needle aspiration (FNA) or imprint cytology, review the literature, and highlight potential diagnostic pitfalls.

METHODS

The authors searched their files for all lesions that were signed out as ASPS or suspicious for ASPS and searched the surgical pathology files for any cases of ASPS that had corresponding cytology. FNA was performed using the standard technique. Scrape preparations were performed on tissues that were sent fresh for frozen section examination.

RESULTS

Ten cases of ASPS were retrieved from 7 patients (male-to-female ratio, 4:3; mean age, 22 years). All had subsequent tissue confirmation. Six specimens were from primary lesions, 3 specimens were from metastases, and 1 intraoperative smear was from a previously aspirated primary mass in a newly diagnosed patient. Anatomic sites of involvement included extremities (5 specimens), trunk/pelvis (3 specimens), oral cavity (1 specimen), and lung (1 specimen). Eight specimens were aspirates, and 2 specimens were intraoperative smears. Nine cases were diagnosed correctly as ASPS/consistent with ASPS, and 1 specimen was diagnosed as "tumor, not otherwise specified". Cytomorphology included variably cellular smears composed of large cells with an enormous amount of finely granular or vacuolated cytoplasm, markedly enlarged nuclei/nucleoli, and bare nuclei. The cytomorphology of some cases revealed a strong similarity to renal cell carcinoma, clear cell type.

CONCLUSIONS

The results of the current study indicated that ASPS has cytomorphology that overlaps with several other neoplasms, including renal cell carcinoma. Nonetheless, the morphologic features, when combined with the clinical presentation, radiologic findings, and ancillary testing, may allow for a specific diagnosis.

Primary alveolar soft part sarcoma of vertebra: a case report and literature review

Alveolar soft part sarcoma (ASPS) is a rare malignant soft tissue tumor, which rarely occurs in bone. We present a case of ASPS in a 23-year-old man with a 2-month history of back pain. Computed tomography scanning and magnetic resonance images demonstrated a destructive process in the 12th thoracic vertebra associated with a unilateral soft tissue mass. The tumor showed evidence of hypervascularity on MRI; it obviously was enhanced on T1-weighted images after injection of Gd-GDPA, and signal voids were shown on all pulse sequences which may help to differentiate ASPS from other tumors of the vertebra. We believe that this is the first case of ASPS arising in a vertebra.

Clinical presentation, treatment, and outcome of alveolar soft part sarcoma in children, adolescents, and young adults

PURPOSE

Alveolar soft part sarcoma is a rare soft tissue neoplasm that can affect children and adolescents. There are few reported series of these patients in the literature. To define the clinical presentation, treatment, and outcome of young people with this rare sarcoma, we reviewed our clinical experience.

METHODS

After institutional review board approval, we examined the records of all patients younger than 25 years old who received treatment at our institution for alveolar soft part sarcoma in the past 30 years. Demographics, tumor sizes, sites and extent of disease, treatments used, progression-free survival, and overall follow-up were evaluated.

RESULTS

Each of the 20 patients presented with a mass. Primary disease sites were thigh (n = 8), trunk (n = 6), retroperitoneum (n = 2), and scalp, neck, forearm, and calf (n = 1 each). Metastatic sites included lymph nodes, lung, and brain. Four patients presented to us with incomplete excision of the primary, and 1 had undergone embolization of what was thought to be a vascular malformation. Although wide local excision provided the best chance for a patient to remain free of disease, 14 (70%) of 20 patients exhibited metastases either at presentation or later. Thirty-one metastasectomies were performed. Chemotherapy was used in 11 patients; radiation was used in 8. Median overall follow-up was 36 months; median progression-free follow-up was 12.5 months. Younger patients tended to have Intergroup Rhabdomyosarcoma Study group I disease. Tumors smaller than 5 cm were associated with longer progression-free survival.

CONCLUSIONS

Achievement of complete microscopic resection is critical in localized alveolar soft part sarcoma, but incomplete excision and misdiagnosis are often encountered. Despite the occurrence of metastases in 70% of patients, 5-year overall survival was 83%. We found an association between smaller tumor size and longer time to progression. We were not able to demonstrate any benefit from chemotherapy or radiation. Metastasectomies have been performed in multiple long-term survivors.