Pseudoneoplastic lesions of the testis and paratesticular structures

Abstract

Pseudotumors or tumor-like proliferations (non-neoplastic masses) and benign mimickers (non-neoplastic cellular proliferations) are rare in the testis and paratesticular structures. Clinically, these lesions (cysts, ectopic tissues, and vascular, inflammatory, or hyperplastic lesions) are of great interest for the reason that, because of the topography, they may be relevant as differential diagnoses. The purpose of this paper is to present an overview of the pseudoneoplasic entities arising in the testis and paratesticular structures; emphasis is placed on how the practicing pathologist may distinguish benign mimickers and pseudotumors from true neoplasia. These lesions can be classified as macroscopic or microscopic mimickers of neoplasia.

Fig. 1

Segmental testicular infarction. a Acute hemorrhagic with reinforcement of the peripheral area (arrows). b Healing fibrosis

Fig. 2

Cholesterol granuloma in the tunica vaginalis (H&E)

Fig. 3

Idiopathic granulomatous orchitis characterized by tubular granulomas (tubular orchitis)

Fig. 4

Malakoplakia. a Macroscopic appearance with a homogeneous aspect. b The characteristic Michaelis–Gutman bodies in the cytoplasm of the macrophages (von Hansemann cells) (PAS)

Fig. 5

Meconium periorchitis. a calcified pearls resulting from the calcification of the remains of squamous cells or lanugo hairs. b Keratin rest in one of the calcifications (H&E)

Fig. 6

Epidermoid cyst, which must only be lined with squamous cell epithelium (H&E)

Fig. 7

a Tubular ectasia of the rete testis located in the mediastinum area of the testes (arrows). b Microscopic aspect (H&E)

Fig. 8

Ectopic adrenocortical tissue. Adrenal cortical nodes surrounded by a connective tissue band in continuity with epididymis. (H&E)

Fig. 9

Splenic–gonadal fusion. The ectopic splenic tissue in close relation with the upper pole of the testis (H&E)

Fig. 10

Normal testicular appendages

Fig. 11

Fibrous pseudotumor. a Well outlined fibrous-like nodule. b Paucicellular hyalinized collagen with calcification

Fig. 12

Lymphocitic orchitis. Lymphocitic cellular infiltration of polyclonal type. a CD45RA (lymphocytes B). b UCHL-1 (lymphocytes T)

Fig. 13

Sertoli cell hyperplasia. a Nonencapsulated nodules of Sertoli cells (Pick’s adenoma). b Sometimes there are areas that mimic Call–Exner bodies

Fig. 14

Leydig cell hyperplasia

Fig. 15

Mesothelial hyperplasia. The bland nucleus, no true invasion and associated inflammatory elements, can be useful to distinguish from malignant mesothelioma

Fig. 16

Vasitis nodosa. Ductular proliferation with a microglandular morphology