Autopsy and Case Reports
Autopsy and Case Reports
Clinical Case Report

Fibrous hamartoma of infancy with sarcomatous transformation: an unusual morphology

Gargi Kapatia; Debajyoti Chatterjee; Kirti Gupta; Amita Trehan

Downloads: 1
Views: 554


Background: Fibrous hamartoma of infancy (FHI) is a rare soft tissue lesion arising as a subcutaneous mass involving the axilla, trunk, and upper arm in infants and children <2yrs. Sarcomatous transformation in FHI is described in anecdotal cases in the literature.

Case Report: We describe one such example arising as a mass in the lower back in a 3-month-old infant. On histology, the tumor contained classic triphasic morphology; however, brisk mitotic activity noted at multiple foci was diagnostically challenging to categorize. The tumor was evaluated for ETV6-NTRK3 fusion to exclude other common differentials.

Conclusion: While FHI may be frequently encountered in infants, rare sarcomatous transformation are known to occur and merits special attention as it can be misdiagnosed. Also, a close follow-up is warranted as the lesion is known to recur locally.


Hamartoma, Neoplasms, Fibrous Tissue, Neoplasms, Connective Tissue, Neoplasms, Connective and Soft Tissue


1 Reye RDK. A consideration of certain “subdermal fibromatous tumors” of infancy. J Pathol Bacteriol. 1956;72(1):149-54. PMid:13367990.

2 Carretto E, Dall’Igna P, Alaggio R, et al. Fibrous hamartoma of infancy: an Italian multiinstitutional experience. J Am Acad Dermatol. 2006;54(5):800-3. PMid:16635660.

3 Fletcher CDM, Powell G, Van Noorden S, McKee PH. Fibrous hamartoma of infancy: a histochemical and immunohistochemical study. Histopathology. 1988;12(1):65-74. PMid:3371894.

4 Lakshminarayanan R, Konia T, Welborn J. Fibrous hamartoma of infancy: a case report with associated cytogenetic findings. Arch Pathol Lab Med. 2005;129(4):520-2. PMid:15794678.

5 Saab ST, McClain CM, Coffin CM. Fibrous hamartoma of infancy: a clinicopathologic analysis of 60 cases. Am J Surg Pathol. 2014;38(3):394-401. PMid:24525510.

6 Al-Ibraheemi A, Martinez A, Weiss SW, et al. Fibrous hamartoma of infancy: a clinicopathologic study of 145 cases, including 2 with sarcomatous features. Mod Pathol. 2017;30(4):474-85. PMid:28059097.

7 Dickey GE, Sotelo-Avila C. Fibrous hamartoma of infancy: current review. Pediatr Dev Pathol. 1999;2(3):236-43. PMid:10191347.

8 Maung R, Lindsay R, Trevenen C, Hwang WS. Fibrous hamartoma of infancy. Hum Pathol. 1987;18(6):652-3. PMid:3596584.

9 Lee JT, Girvan DP, Armstrong RF. Fibrous hamartoma of infancy. J Pediatr Surg. 1988;23(8):759-61. PMid:3171848.

10 Lakshminarayanan R, Konia T, Welborn J. Fibrous hamartoma of infancy: a case report with associated cytogenetic findings. Arch Pathol Lab Med. 2005;129(4):520-2. PMid:15794678.

11 Imaji R, Goto T, Takahashi Y, Akiyama T, Yamadori I. A case of recurrent and synchronous fibrous hamartoma of infancy. Pediatr Surg Int. 2005;21(2):119-20. PMid:15645249.

12 McGowan J IV, Smith CD, Maize J Jr, Cook J. Giant fibrous hamartoma of infancy: a report of two cases and review of the literature. J Am Acad Dermatol. 2011;64(3):579-86. PMid:20598395.

13 Goldblum JR, Weiss SW. Fibrous tumors of infancy and childhood. In: Strauss M, editor. Enzinger and weiss’s soft tissue tumors. 4th ed. St Louis, Mo: The CV Mosby Co; 2000. p. 347–408.

14 Bourgeois JM, Knezevich SR, Mathers JA, Sorensen PH. Molecular detection of the ETV6-NTRK3 gene fusion differentiates congenital fibrosarcoma from other childhood spindle cell tumors. Am J Surg Pathol. 2000;24(7):937-46. PMid:10895816.

Submitted date:

Accepted date:

Publication date:

626ac572a953954b10181e82 autopsy Articles
Links & Downloads

Autops Case Rep

Share this page
Page Sections