An unusual case of spontaneous regression of stage IIIB lymphocytic predominant sclerosing Hodgkin's lymphoma

A 53-year-old female patient with no medical history presented with a groin lump and B symptoms. She underwent an USS pelvis to investigate. This revealed an unexpected mass in the epigastrium. A subsequent staging CT and excision biopsy of a groin lymph node and pre-treatment PET CT were performed.

USS showed an enlarged lymph node in right groin (Fig. 1) and an unexpected epigastric mass measuring 74 mm maximum diameter (Fig. 2).
The CT thorax abdomen and pelvis showed lymph node enlargement above and below the diaphragm, the bulk of which formed a conglomerate in the para-aortic area and small bowel mesenteric root. There was moderate splenomegaly of 16 cm with some suspicious hypodense deposits (Figures 4-7). Normal appearances of the liver, pancreas and adrenals. No intrapulmonary nodules or destructive skeletal pathology was noted (images in lung and bone windows not provided). Preliminary staging was IIIB according to the Ann Arbour classification.
A subsequent pre-treatment staging PET CT two months after presentation showed unusual findings; There had been anatomic reduction in size of the previously demonstrated adenopathy, the spleen was now normal in size. No abnormal metabolic activity was demonstrated (Fig. 8-10). Appearances were suggestive of spontaneous resolution of the previous disease.

In 2015 there were 2,110 new cases of Hodgkin Lymphoma diagnosed in the UK, with an 80% survival of 10 years or more in 2010-11 in England and Wales. [1]
Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is a rare subtype of Hodgkin lymphoma. Around 1 in 20 Hodgkin lymphomas diagnosed each year are NLPHL (5%). [2]
NLPHL commonly presents at an early stage with peripheral lymphadenopathy. It rarely presents with "B "symptoms, bulky mediastinal or abdominal nodal disease or at extranodal sites. [3]
The disease is staged according to the Ann Arbour classification, 75% of cases are stage I or II at the time of diagnosis, 25% of cases are stage III and IV at diagnosis and require systemic treatment with chemotherapeutic agents. [4]

Spontaneous regression of any malignancy is a rare occurrence. [5] There are very few case reports describing spontaneous regression of NLPHL in the literature. It is a rare phenomenon and the exact mechanism is not fully understood. There are proposed factors that are thought to influence spontaneous regression of a malignancy; most are attributed to immunological factors. [6]

Following the initial CT scan at presentation, our patient underwent excision biopsy of the right groin lymph node. Histology reported the morphology and immunophenotype of nodular lymphocyte-predominant Hodgkin's lymphoma with sclerosis.
After confirmation of the diagnosis at a regional haematology panel, the patient underwent a pre-treatment staging CT PET. This showed no evidence of abnormal metabolic activity or FDG uptake. The CT images of the scan also confirmed regression in the multiple sites of lymphadenopathy, confirming almost total regression of disease.
The original histology was then reviewed and the diagnosis was confirmed by a second histopathologist. The patient was reviewed in clinic and discussed in the haematology MDT, it was confirmed that the patient had not taken any chemotherapeutic treatment, over the counter or holistic medication. There was also no history of infectious disease. A plan for routine surveillance by CT was decided upon.