Myofibromas with atypical features: Expanding the morphologic spectrum of a benign entity

Konstantinos Linos, Jodi Carter, Jerad M. Gardner, Andrew L. Folpe, Sharon W. Weiss, Mark A. Edgar

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Typical myofibromas are biphasic tumors composed of a central zone of immature spindled to rounded cells arranged in a pericytic pattern and a peripheral zone of myoid nodules. Central necrosis is occasionally seen. A small but undefined subset of myofibromas displays atypical features that may lead to a misdiagnosis of sarcoma. To more completely characterize these tumors and define their behavior, we analyzed our experience with myofibromas having 1 or more atypical features including hypercellularity, absent or inconspicuous, poorly demarcated myoid nodules, infiltrative growth pattern, and perineural invasion. Of 266 cases of myofibromas, 24 cases were retrieved on the basis of pathology reports in which atypical features were mentioned. The tumors presented in 16 male and 8 female individuals (mean age 17 y; range, 2wk to 62 y) as masses of variable size (mean 3.0 cm; range, 1.5 to 6.5 cm). Fourteen cases arose on the head and neck and 10 cases on the limbs. The referring or suspected diagnosis was sarcoma in 8 cases. The tumors were typically more cellular than ordinary myofibroma with levels of cellularity similar to that expected in fibrosarcoma (22/24). In addition, they displayed inconspicuous, loosely cohesive (22/24) or absent myoid nodules (2/24), infiltrating borders (19/24), intravascular growth (5/24), and perineural invasion/nerve entrapment (6/24). The mean mitotic rate was 5 mitoses/10 high-power fields, but no tumor showed significant cytologic atypia. The tumors were positive for actins (11/11) and CD34 (2/8). Follow-up in 14 patients revealed no distant metastases. We conclude that a small subset of myofibromas shows atypical features that complicate the diagnosis but do not adversely affect outcome.

Original languageEnglish (US)
Pages (from-to)1649-1654
Number of pages6
JournalAmerican Journal of Surgical Pathology
Volume38
Issue number12
DOIs
StatePublished - Jan 1 2014

Fingerprint

Myofibroma
Neoplasms
Sarcoma
Nerve Compression Syndromes
Fibrosarcoma
Growth
Diagnostic Errors
Mitosis
Actins
Necrosis
Neck
Extremities
Head
Pathology
Neoplasm Metastasis

Keywords

  • Fibrosarcoma
  • Myofibroma
  • Myoid nodules
  • Perivascular myoid cell tumor

ASJC Scopus subject areas

  • Anatomy
  • Surgery
  • Pathology and Forensic Medicine

Cite this

Myofibromas with atypical features : Expanding the morphologic spectrum of a benign entity. / Linos, Konstantinos; Carter, Jodi; Gardner, Jerad M.; Folpe, Andrew L.; Weiss, Sharon W.; Edgar, Mark A.

In: American Journal of Surgical Pathology, Vol. 38, No. 12, 01.01.2014, p. 1649-1654.

Research output: Contribution to journalArticle

Linos, Konstantinos ; Carter, Jodi ; Gardner, Jerad M. ; Folpe, Andrew L. ; Weiss, Sharon W. ; Edgar, Mark A. / Myofibromas with atypical features : Expanding the morphologic spectrum of a benign entity. In: American Journal of Surgical Pathology. 2014 ; Vol. 38, No. 12. pp. 1649-1654.
@article{8483f43ef6e64daa859be2c642db04c6,
title = "Myofibromas with atypical features: Expanding the morphologic spectrum of a benign entity",
abstract = "Typical myofibromas are biphasic tumors composed of a central zone of immature spindled to rounded cells arranged in a pericytic pattern and a peripheral zone of myoid nodules. Central necrosis is occasionally seen. A small but undefined subset of myofibromas displays atypical features that may lead to a misdiagnosis of sarcoma. To more completely characterize these tumors and define their behavior, we analyzed our experience with myofibromas having 1 or more atypical features including hypercellularity, absent or inconspicuous, poorly demarcated myoid nodules, infiltrative growth pattern, and perineural invasion. Of 266 cases of myofibromas, 24 cases were retrieved on the basis of pathology reports in which atypical features were mentioned. The tumors presented in 16 male and 8 female individuals (mean age 17 y; range, 2wk to 62 y) as masses of variable size (mean 3.0 cm; range, 1.5 to 6.5 cm). Fourteen cases arose on the head and neck and 10 cases on the limbs. The referring or suspected diagnosis was sarcoma in 8 cases. The tumors were typically more cellular than ordinary myofibroma with levels of cellularity similar to that expected in fibrosarcoma (22/24). In addition, they displayed inconspicuous, loosely cohesive (22/24) or absent myoid nodules (2/24), infiltrating borders (19/24), intravascular growth (5/24), and perineural invasion/nerve entrapment (6/24). The mean mitotic rate was 5 mitoses/10 high-power fields, but no tumor showed significant cytologic atypia. The tumors were positive for actins (11/11) and CD34 (2/8). Follow-up in 14 patients revealed no distant metastases. We conclude that a small subset of myofibromas shows atypical features that complicate the diagnosis but do not adversely affect outcome.",
keywords = "Fibrosarcoma, Myofibroma, Myoid nodules, Perivascular myoid cell tumor",
author = "Konstantinos Linos and Jodi Carter and Gardner, {Jerad M.} and Folpe, {Andrew L.} and Weiss, {Sharon W.} and Edgar, {Mark A.}",
year = "2014",
month = "1",
day = "1",
doi = "10.1097/PAS.0000000000000270",
language = "English (US)",
volume = "38",
pages = "1649--1654",
journal = "American Journal of Surgical Pathology",
issn = "0147-5185",
publisher = "Lippincott Williams and Wilkins",
number = "12",

}

TY - JOUR

T1 - Myofibromas with atypical features

T2 - Expanding the morphologic spectrum of a benign entity

AU - Linos, Konstantinos

AU - Carter, Jodi

AU - Gardner, Jerad M.

AU - Folpe, Andrew L.

AU - Weiss, Sharon W.

AU - Edgar, Mark A.

PY - 2014/1/1

Y1 - 2014/1/1

N2 - Typical myofibromas are biphasic tumors composed of a central zone of immature spindled to rounded cells arranged in a pericytic pattern and a peripheral zone of myoid nodules. Central necrosis is occasionally seen. A small but undefined subset of myofibromas displays atypical features that may lead to a misdiagnosis of sarcoma. To more completely characterize these tumors and define their behavior, we analyzed our experience with myofibromas having 1 or more atypical features including hypercellularity, absent or inconspicuous, poorly demarcated myoid nodules, infiltrative growth pattern, and perineural invasion. Of 266 cases of myofibromas, 24 cases were retrieved on the basis of pathology reports in which atypical features were mentioned. The tumors presented in 16 male and 8 female individuals (mean age 17 y; range, 2wk to 62 y) as masses of variable size (mean 3.0 cm; range, 1.5 to 6.5 cm). Fourteen cases arose on the head and neck and 10 cases on the limbs. The referring or suspected diagnosis was sarcoma in 8 cases. The tumors were typically more cellular than ordinary myofibroma with levels of cellularity similar to that expected in fibrosarcoma (22/24). In addition, they displayed inconspicuous, loosely cohesive (22/24) or absent myoid nodules (2/24), infiltrating borders (19/24), intravascular growth (5/24), and perineural invasion/nerve entrapment (6/24). The mean mitotic rate was 5 mitoses/10 high-power fields, but no tumor showed significant cytologic atypia. The tumors were positive for actins (11/11) and CD34 (2/8). Follow-up in 14 patients revealed no distant metastases. We conclude that a small subset of myofibromas shows atypical features that complicate the diagnosis but do not adversely affect outcome.

AB - Typical myofibromas are biphasic tumors composed of a central zone of immature spindled to rounded cells arranged in a pericytic pattern and a peripheral zone of myoid nodules. Central necrosis is occasionally seen. A small but undefined subset of myofibromas displays atypical features that may lead to a misdiagnosis of sarcoma. To more completely characterize these tumors and define their behavior, we analyzed our experience with myofibromas having 1 or more atypical features including hypercellularity, absent or inconspicuous, poorly demarcated myoid nodules, infiltrative growth pattern, and perineural invasion. Of 266 cases of myofibromas, 24 cases were retrieved on the basis of pathology reports in which atypical features were mentioned. The tumors presented in 16 male and 8 female individuals (mean age 17 y; range, 2wk to 62 y) as masses of variable size (mean 3.0 cm; range, 1.5 to 6.5 cm). Fourteen cases arose on the head and neck and 10 cases on the limbs. The referring or suspected diagnosis was sarcoma in 8 cases. The tumors were typically more cellular than ordinary myofibroma with levels of cellularity similar to that expected in fibrosarcoma (22/24). In addition, they displayed inconspicuous, loosely cohesive (22/24) or absent myoid nodules (2/24), infiltrating borders (19/24), intravascular growth (5/24), and perineural invasion/nerve entrapment (6/24). The mean mitotic rate was 5 mitoses/10 high-power fields, but no tumor showed significant cytologic atypia. The tumors were positive for actins (11/11) and CD34 (2/8). Follow-up in 14 patients revealed no distant metastases. We conclude that a small subset of myofibromas shows atypical features that complicate the diagnosis but do not adversely affect outcome.

KW - Fibrosarcoma

KW - Myofibroma

KW - Myoid nodules

KW - Perivascular myoid cell tumor

UR - http://www.scopus.com/inward/record.url?scp=84914705747&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84914705747&partnerID=8YFLogxK

U2 - 10.1097/PAS.0000000000000270

DO - 10.1097/PAS.0000000000000270

M3 - Article

C2 - 24921644

AN - SCOPUS:84914705747

VL - 38

SP - 1649

EP - 1654

JO - American Journal of Surgical Pathology

JF - American Journal of Surgical Pathology

SN - 0147-5185

IS - 12

ER -