This year we received 10 cases of fungal lymphadenitis in calves, out of a total of 55 suspected tuberculosis samples (18.2%). In this post we have compiled images to familiarize you with the variety of the macroscopic looks of these lesions.

Under no circumstances should this sort of lesions not be sent to the laboratory for analysis, as macroscopically it cannot be ruled out that they are tuberculous granulomas.

In all the cases presented below, the laboratory diagnosis was based on the identification under the microscope of the presence of fungal hyphae inside the lesions, but the causal fungal species was not identified. You can read a previously published post where the fungus Rhizomucor pusillus was identified.

Left tracheobronchial lymph node of a 12-month-old male fleckvieh calf. It also had lesions in the retropharyngeal and caudal mediastinal lymph nodes. The lesions crackled when cut as they were mineralized.

Mediastinal and retropharyngeal lymph nodes of a 13-month-old male Belgian blue calf. It also had lesions in his left tracheobronchial lymph node. In this case the lesions did not crackle when sectioned.

Mesenteric lymph nodes of an 11-month-old crossedbred male calf. You can see more pictures of this case in a previous post in the self-learning section “What is your diagnosis? (81) ”. These were spherical lesions, well circumbscribed and with a necrotic core.

Mesenteric lymph node of a 14-month-old male Friesian calf. Multiple 2-3mm lesions are observed throughout the lymph node. The consistency of the nodules is hardened but does not crackle upon section.

Tracheobronchial and mediastinal lymph nodes of an 11-month-old male Angus calf.

Left tracheobronchial lymph node of a 10-month-old crossbred female calf. The carcass showed no more visible lesions, when sectioned the lesion crackled.

Twelve month old crossbred female calf with mineralized granulomatous lesions in the submandibular, mesenteric, tracheobronchial, and mediastinal lymph nodes (pictured).

Mesenteric lymph node of an 11-month-old crossbred female calf. The lesion crackles when sectioned.

Two mesenteric lymph node lesions of an 11-month-old crossbred female calf. The lesions crackle when sectioned. In this case the lesions were also spherical with well defined borders.

An 11-month-old, Angus, female calf with spherical granulomatous lesions, well defined and mineralized in the lung parenchyma (P) and multiple lymph nodes including: tracheobronchial (Ln TB), mediastinal (Ln MD) and mesenteric.